Evolutionary Architecture & Fitness Functions
Expressing architectural intent as executable, continuously verified constraints so both humans and agents get fast feedback on whether implementations conform to design.
Also known as: fitness functions, Architecture as Code, architecture as code, deterministic constraints, feedback framework (vs. testing framework), konversasjonell arkitektur (conversational architecture), conversational architecture, fart og flyt (speed and flow), behavioral verification vs. capability verification, nine intersections, CALM, CALM Hub, Common Architecture Language Model (FINOS)
How authors use it
Oldest first (extraction date when no publication date is known).
| Author | Their term | Their meaning |
|---|---|---|
| Agents don't know what good looks like. And that's exactly the problem. Luca Mezzalira · 2025-01-01 | behavioral verification vs. capability verification | Behavioral: does the code satisfy functional specs (unit/integration tests). Capability: does the system exhibit required operational qualities (performance, resilience, security) at scale. |
| Agents don't know what good looks like. And that's exactly the problem. Luca Mezzalira · 2025-01-01 | fitness functions | Deterministic, automated checks that continuously verify whether a system stays within its architectural constraints — promoted by Ford & Parsons since 2017 as part of evolutionary architecture. |
| 14) Øystein Ulseth pendler mellom å lede og levere Truls Jørgensen og Audun Fauchald Strand — Heis Podcast · 2026-04-07 | fart og flyt (speed and flow) | The properties a modern architecture should optimise for: teams shipping with minimum friction. Loose coupling and high cohesion are the levers; central architecture boards are now a flow-limiting factor at large scale. |
| 14) Øystein Ulseth pendler mellom å lede og levere Truls Jørgensen og Audun Fauchald Strand — Heis Podcast · 2026-04-07 | konversasjonell arkitektur (conversational architecture) | Andrew Harmel-Law's model of distributed architecture decision-making: teams are empowered to make architecture choices the way they are empowered for development decisions, on the condition that they consult relevant stakeholders, document, and inform a central body — which then no longer 'approves' decisions but receives them. |
| Architecture as Code to Teach Humans and Agents About Architecture Neal Ford and Mark Richards · 2026-04-15 | Architecture as Code | Expressing all aspects of software architecture — structure, constraints, relationships, dependencies — in executable, version-controlled code rather than diagrams or prose, so that conformance can be verified automatically. |
| Architecture as Code to Teach Humans and Agents About Architecture Neal Ford and Mark Richards · 2026-04-15 | feedback framework (vs. testing framework) | A system that notifies architects when implementation diverges from design, framing divergence as information (potential feedback) rather than as failure (test breakage). A new component is not an error — it is a signal to assess. |
| Architecture as Code to Teach Humans and Agents About Architecture Neal Ford and Mark Richards · 2026-04-15 | deterministic constraints | Objective, measurable architectural rules (e.g., cyclomatic complexity limits, dependency direction rules) that can be evaluated computationally without human judgment. |
| Architecture as Code to Teach Humans and Agents About Architecture Neal Ford and Mark Richards · 2026-04-15 | nine intersections | The nine areas where software architecture intersects other parts of the development ecosystem: implementation, engineering practices, infrastructure, generative AI, team topologies, business concerns, enterprise architecture, data, and integration architecture. |
| Strategy Making Gets an AI Boost Gretchen Gavett · 2026-08-18 | calm | As Gratton uses it (quoted): 'the mental space needed to exercise good judgement' — a deliberately protected, practiced state, not passive relaxation, that lets someone navigate uncertainty and pressure. |
| Presentation: APIs for Agents: Rethinking API Programs in the MCP Era Jim Gough, Andreea Niculcea · 2026-09-23 | CALM | FINOS's (financial open-source) 'Architecture as Code' project: a JSON-schema core model for expressing architecture as typed boxes and arrows, plus a CLI, a hosted registry/visual layer ('CALM Hub'), and AI integration (prompts/chat modes). It is the mechanism Morgan Stanley uses to make architecture, patterns, and controls machine-readable and enforceable. |
Documents (13)
- Presentation: APIs for Agents: Rethinking API Programs in the MCP Era Jim Gough, Andreea Niculcea · 2026-09-23 Reader 🖥️
As agent protocols (MCP, then A2A, then whatever comes next) reshape how consumers reach enterprise systems, Morgan Stanley argues platforms should keep APIs as the stable, governed foundation and use Architecture-as-Code (CALM) to encode, version, and automatically enforce security/governance controls and deployment gates across every protocol adapter built on top — so the organization can adopt new interaction protocols quickly, and evolve already-deployed services at scale, without sacrificing safety or consistency. - Strategy Making Gets an AI Boost Gretchen Gavett · 2026-08-18 Reader 🖥️
As curator of The Insider, Gavett presents two arguments that senior leaders should trade fixed, precomputed plans for continuous option-generation under protected human judgment: AI dissolves the bounded-rationality limits that forced strategy-making into static frameworks like SWOT and Porter's five forces (per Felipe Csaszar), and longer, less predictable careers require small low-stakes experiments plus deliberately protected reflection time rather than a single career plan (per Lynda Gratton). - Article: Agentic Fitness Functions: Extending Evolutionary Architecture Beyond Deterministic Rules Hemant Kumar Mahato, Łukasz Sieczkowski, Vijayasenthilkumar Kuppusamy · 2026-08-17 source ↗ Reader 🖥️
Deterministic fitness functions should remain the primary architectural governance mechanism, but calibrated, evidence-scoped, escalation-capable AI 'agentic fitness functions' should be added as an advisory judgment layer for architectural concerns that are evidence-bound but not reducible to a rule — boundary fidelity, semantic contract drift, stale ADR assumptions — so that architectural judgment itself becomes observable, auditable, and, where patterns repeat, convertible back into deterministic guardrails. - The Hard-Stop Rule: From 3 HCM Monoliths to 120 Domain Microservices Prashanth Pasham · 2026-07-28 source ↗ Reader 🖥️
By imposing an absolute rule -- never modify the legacy HCM monoliths again, only add new domain microservices -- and pairing it with three platform investments (self-service provisioning, an API-gateway routing seam, and a cached feature-flag rollback layer) that keep the resulting per-story cost tax affordable, a team can fund and execute a full monolith-to-microservices migration as a side effect of ordinary roadmap work, with no dedicated migration budget or program. - Presentation: Clean Architecture for Serverless: Business Logic You Can Take Anywhere Elena van Engelen · 2026-07-27 source ↗ Reader 🖥️
Structuring Function-as-a-Service applications with a simplified Clean Architecture — a domain and application layer with zero cloud dependencies, whose separation from infrastructure is enforced not by convention but by Gradle module boundaries, wired to cloud entry points via Spring Cloud Function's dependency injection — lets a team write business logic once and deploy it, materially unchanged, to multiple serverless cloud providers, eliminating vendor lock-in without giving up native cloud capabilities. - An Evolutionary Architecture Pattern for Managing AI's Pace of Change Joe Price, Branimir Đurek, Pavlos Migkiros, Trevor Dearham · 2026-07-27 source ↗ Reader 🖥️
Because AI capabilities, protocols, and threats now change faster than enterprise systems can safely absorb — a gap the authors treat as permanent rather than a phase to wait out — organizations should deliberately concentrate the fastest-moving AI concerns (model routing, identity, action policy, segmentation, content guarding, and audit) into one architectural seam, the AI gateway, so the rest of the enterprise can remain stable, and should build that seam proactively rather than at the higher cost of building it after an incident forces the issue. - Comprehension at AI Speed: Building a Context Store for Evolutionary Architecture Stella Berhe, Stephan Bragner, Vikram Maran, Anand Jayaraman · 2026-07-14 source ↗ Reader 🖥️
Because AI has decoupled writing code from understanding it, engineering organizations must run spec-anchored specification-driven development, test-driven development, and architectural fitness functions together as one verification system so that their combined artifacts form a versioned, queryable "context store" — making comprehension a lifecycle property of evolutionary architecture that both human reviewers and AI agents can draw on, rather than a pre-merge concern that AI-generated speed otherwise outruns. - Podcast: Formal Methods for Every Engineer in an AI-Powered Future Gabriela Moreira (guest); host Shane Hastie (InfoQ) · 2026-07-10 Reader 🖥️
Formal methods are a practical tool for reasoning about the edge cases of complex distributed and concurrent systems, and because AI in 2026 collapses the historic barriers to writing specifications and the glue code that binds them to real implementations, the profession's enduring human work shifts to defining which system behaviours are correct — the judgment AI cannot take over. - What Survived Contact Sam Ruby · 2026-07-01 source ↗ Reader 🖥️
When agents write the code, rigor does not vanish but migrates to the objective and its evaluation; directing an agent is therefore a management act (a hire, not a tool-use) whose one non-delegable duty is owning the objective and the oracle that checks it. - Three more static code analysis sensors Birgitta Böckeler (published on martinfowler.com) · 2026-05-20 source ↗ Reader 🖥️
For maintainability concerns that cross file and module boundaries, computational static-analysis sensors (dependency rules, coupling metrics) can usefully enforce a few structural invariants but cannot judge what coupling is appropriate; the most productive sensor is an inferential, prompt-driven AI modularity review that reads the code itself, with the deterministic tools relegated to enforcement of known rules and to triage of review attention. - Architecture as Code to Teach Humans and Agents About Architecture Neal Ford and Mark Richards · 2026-04-15 Reader 🖥️
Software architecture should be defined as code — capturing structural constraints deterministically — so that both human developers and AI agents can receive fast feedback on whether implementations conform to design intent. - 14) Øystein Ulseth pendler mellom å lede og levere Truls Jørgensen og Audun Fauchald Strand — Heis Podcast · 2026-04-07 source ↗ Reader 🖥️
The best technology leaders pendle (commute) deliberately between leading and delivering — driven not by career ambition but by the joy of building at the right level of abstraction — because crossing that boundary in both directions is what makes you precise: a hands-on background gives leaders pragmatism about complexity and trade-offs, while a leadership background gives builders the holistic, risk-aware perspective that lets them choose what to build. - Agents don't know what good looks like. And that's exactly the problem. Luca Mezzalira · 2025-01-01 source ↗ Reader 🖥️
Agentic AI systems lack the judgment to distinguish correct behavior from merely passing checks, which means that deterministic architectural guardrails — fitness functions, capability verification, explicit boundary definitions — are not optional but imperative; and the sociotechnical readiness of the humans and organizations that must own the generated systems is the overlooked bottleneck.
Propositions touching this concept (18)
By publication month, oldest first (extraction month when no publication date is known).
2025-01
- explicitestablishedDeterministic guardrails (fitness functions, capability tests, boundary definitions) around nondeterministic agents are not optional but imperative.
2026-04
- explicitdevelopedDefining architecture as code creates a fast feedback loop that lets architects detect when implementation diverges from design.
- explicitestablishedAI agents can only work toward acceptable solutions when deterministic constraints exist to define success.
- implicitdevelopedArchitecture can be objectively and precisely defined across all nine intersections of the development ecosystem.
2026-05
- explicitRituals and predictability calm the human brain and create the conditions for trust; they function as social infrastructure that persists even when team composition changes.
2026-07
- implicitcorroboratedGuardrails, fitness functions, and CI/CD pipelines are not optional overhead but the mechanism that converts AI-driven velocity into safe value rather than accumulated debt.
- explicitRunning spec-anchored SDD, TDD, and architectural fitness functions together, on one cadence, as a single verification system produces the context store as an emergent byproduct; none of the three disciplines is individually new, but their deliberate integration is.
- explicitEach of the three disciplines collapses into a specific, named failure mode when its accompanying social practice is absent: specs decay into "spec-first-then-discard" documentation theater, TDD becomes a coverage-gate tax written after the fact, and fitness functions get bypassed by a synchronous review board or an overloaded single senior engineer.
- explicitA leader should maintain 'happy high status' — projecting calm and control under chaos — because the team feeds off the leader's emotional state and panic cascades.
- implicitThe composure a leader projects is a deliberate performance decoupled from felt experience — calm is manufactured internally and then displayed, not experienced.
2026-08
- explicitDeterministic fitness functions should remain the primary enforcement mechanism for measurable architectural invariants — dependency direction, contract shape, latency budgets, security posture, policy checks.
- explicitAgentic fitness functions add value specifically where architectural risk is evidence-bound but judgment-heavy — boundary fidelity, semantic contract drift, workflow coupling, stale ADR assumptions — not where a rule or threshold already suffices.
- explicitA life can be modeled as eight threads — four of productivity (mastery, knowing, cooperating, amplifying/AI) and four of nurture (relationships/friendship, calm, adventure, and managing energy) — that are present at all times; people, usually unconsciously, choose which threads to strengthen and which to leave fragile, and over-investing only in productivity threads is what produces burnout.
- explicitdevelopedLonger working lives (50-60 years) combined with AI-accelerated change mean careers are becoming both longer and harder to predict, and leaders should respond with three practices rather than a single fixed plan: prepare before you need to (small, low-stakes experiments), commit to what lasts (durable capabilities and relationships), and protect time for judgment (deliberately protected reflective 'calm').
2026-09
- explicitBecause architecture, patterns, and deployments are held as versioned, machine-readable data (CALM Hub as 'golden source'), a platform team can push a new 'platform opinion' across all existing production deployments as a zero-downtime 'operational rollout' without the owning teams initiating anything.
- explicitAutomated deployment gates (pattern-conformance lookup, CALM CLI JSON-schema + spectral validation, later smoke tests/security review/drift detection) give developers PR-style feedback before promotion and apply identically whether it's the 1st or the 100th deployment.
- explicitcontestedTime-to-production for a new Morgan Stanley API dropped from roughly two years (the first API) to about six months, and now to one to two weeks, which Jim attributes to CALM's automated security approvals.
- implicitEncoding platform opinions as versioned, machine-readable architecture — rather than as documentation or discretionary policy — is what simultaneously enables both automated per-deployment gates and mass, centrally-triggered operational rollouts; both draw on the same underlying CALM data model.
Tensions
How far can day-2 operations be handed to self-healing / autonomous remediation?
from: What did the participants of the Thoughtworks 'Future of Software Engineering' Europe retreat (mid-2026) conclude about how agentic AI is reshaping software engineering?
- Looking back at the Future of Software Engineering unconference (Bartosz Ocytko): A self-healing platform foundation should make whole classes of failure 'disappear', with increasingly autonomous background 'guardrail' agents refactoring, adding tests, and protecting invariants.
- AI Is Changing Software Engineering. The Fundamentals Still Matter. (Abby Bangser): Detection, context, and suggestion are safe wins, but automated remediation must remain an intentional, context-specific decision, not a default end state.
- What Survived Contact (Sam Ruby): Self-healing has, in practice, only moved halfway: diagnosis is automated while remediation is deliberately withheld from the machine.
Assessment: Ruby's report is descriptive (where practice actually stands) and Ocytko's is aspirational (where platforms could go); the gap between 'remediation is withheld' and 'failure modes disappear' is precisely the distance the optimists are projecting across. Bangser supplies the reason the gap may not close on efficiency grounds alone — the withheld human step is also the learning step.
Is the value question genuinely settled by evidence, or does uncertainty and sampling bias still dominate?
from: What did the participants of the Thoughtworks 'Future of Software Engineering' Europe retreat (mid-2026) conclude about how agentic AI is reshaping software engineering?
- Notes from FOSE Europe (Giles Edwards-Alexander): The evidence is in; the value is clearly here and here to stay.
- Finding Comfort in the Uncertainty (Annie Vella): Nobody has it figured out; there is more uncertainty than certainty, and the shared set of questions is the real outcome.
- What Survived Contact (Sam Ruby): 'Rigor migrates' is about as settled as this young field gets, but the room is a non-random, incumbent-tilted sample, and the doubt is currently better evidenced than the hope.
Assessment: The single sharpest divergence, and it sits directly under the headline whether-to-how convergence: they narrate the same shift but disagree on what it establishes. Edwards-Alexander and Herlein read the room's confidence as evidence; Vella and Ruby read the same room as a self-selected in-group. Ruby has the better of it methodologically — he is the only one to interrogate the sample and to notice the evidence is asymmetric (upside anecdotal, downside studied), which is uncomfortable precisely because the cohort's confidence is built on the weaker side.
Where is the locus of safety for non-engineers / citizen developers building software?
from: What did the participants of the Thoughtworks 'Future of Software Engineering' Europe retreat (mid-2026) conclude about how agentic AI is reshaping software engineering?
- Looking back at the Future of Software Engineering unconference (Bartosz Ocytko): In a tightly-constrained self-healing platform — not universal upskilling.
- What Survived Contact (Sam Ruby): In the director's management skill — a non-engineer steering an agent has made a hire, and the requirement is that they can manage by objective.
- AI Is Changing Software Engineering. The Fundamentals Still Matter. (Abby Bangser): In API-first, MCP-accessible tooling that supports rather than restricts the new builders.
- Why did Martin Fowler invite 60 engineers to a ski resort? (Ivett Ördög): It is genuinely unsolved — the tension between democratisation and its risks is an open question.
Assessment: Four different answers to the same governance question: the platform (Ocytko), the director's discipline (Ruby), the tooling interface (Bangser), or nobody-knows-yet (Ördög). Ruby and Ocytko are the true opposites — Ruby puts the burden on a human management skill, Ocytko designs the human out by making failure modes disappear in the platform. That both are held by attendees of one retreat is a measure of how unsettled the citizen-developer problem is.
Is code a durable artifact to be maintained, or an ephemeral byproduct regenerated from a more durable source (spec/objective)?
from: What is the future of software development in the agentic/AI age?
- We've Stopped Arguing About Whether AI Changes Software (Greg Herlein): Code is (or is becoming) ephemeral — a disposable byproduct the agent regenerates from the spec; the spec is 'the point.'
- Fragments: February 4 (Martin Fowler (Feb 4)): When coding is free, the specification-plus-tests becomes the durable, primary engineering artifact.
- Software Design in the Agentic Age: Place Your Bets (Mathias Verraes): Specifications could replace code as the source of truth, but throwaway regeneration is a bet he is unwilling to make; keep code durable and revertible.
- Why did Martin Fowler invite 60 engineers to a ski resort? (Ivett Ördög): Code endures because the winning agents behave like engineers moulding a maintained codebase, not compilers regenerating from scratch.
- What Survived Contact (Sam Ruby): The durability question is a category error — what endures is neither the code nor the prose spec but the objective and its oracle.
Assessment: The most-cited open question of the corpus, and genuinely unresolved (Herlein: 'no consensus here. None.'). The 'code is the better spec' counter is strong — code is unambiguous, executable, deterministic, whereas a prose spec is reinterpreted each run, which sits in tension with verifiability being the quality bar. Ruby's move is the most defensible: it dissolves the code-vs-spec fight by locating durability in the evaluation rather than any representation. Verraes and Ördög expose the load-bearing empirical unknown — nobody has data on regenerate-vs-patch cost or on long-term evolvability of agent-maintained code.
Where does the non-delegable human asset now live — the harness/platform, the oracle, the fundamentals, or the developer's understanding?
from: What is the future of software development in the agentic/AI age?
- Notes from FOSE Europe (Giles Edwards-Alexander): In the harness — the continuously-evolving scaffolding of architecture guidance and rigour around the agents — though it must stay team-distributed, not centralized.
- What Survived Contact (Sam Ruby): In the oracle — the objective's evaluation is the single thing the person directing the model cannot delegate back to it.
- Jimmy Nilsson's Post — reflections after the Thoughtworks 'Future of Software Development' retreat (Jimmy Nilsson): In the fundamentals plus a renewed 'Extreme Humanism' — the durable disciplines and the conspicuously human element.
- AI Is Changing Software Engineering. The Fundamentals Still Matter. (Abby Bangser): In right-sized boundaries and the operational loop — humans must stay in operations because their learning is the irreplaceable asset.
- Fragments: February 9 (Martin Fowler (Feb 9)): In the developer's model-building and shared understanding — the craft of devising abstractions to reason about the domain.
Assessment: This is the deepest structural disagreement — every author agrees a human residue remains but nominates a different residue, and the choice determines what to invest in and what to teach. The harness-centric (Edwards-Alexander), oracle-centric (Ruby), fundamentals-centric (Nilsson/Bangser), and understanding-centric (Fowler) camps are not merely emphases: they imply different career ladders, different hiring, and different failure modes. Ruby's oracle and Bangser's operational-learning are the most operationally concrete; Nilsson's is the least argued. The absence in the corpus of anyone who holds 'nothing is non-delegable' is itself telling (see unexamined assumptions).
How far should software be automated — toward the fully-autonomous dark/software factory, or held back to bounded autonomy with humans in the loop?
from: What is the future of software development in the agentic/AI age?
- Why did Martin Fowler invite 60 engineers to a ski resort? (Ivett Ördög): Full automation is genuinely viable in context and she is 'ironically' being pulled toward the dark-factory camp.
- Looking back at the Future of Software Engineering unconference (Bartosz Ocytko): The aspirational endpoint is a largely self-evolving software factory; humans build and operate the backbone rather than the application.
- AI Is Changing Software Engineering. The Fundamentals Still Matter. (Abby Bangser): Bounded autonomy — keep humans in the operational loop; automated remediation must stay an intentional decision.
- What Survived Contact (Sam Ruby): Self-healing has stalled halfway on purpose: diagnosis is automated, remediation withheld from the machine.
- Software Design in the Agentic Age: Place Your Bets (Mathias Verraes): Dark factories are safe only for orgs that already have high test coverage, skilled engineers, and a quality culture; most should cover fundamentals first and stay revertible.
Assessment: The spectrum runs from Ördög/Ocytko (full automation is arriving and desirable) to Bangser/Ruby/Verraes (deliberately withhold the last step). The decelerationists have the better of the safety argument today — Ruby's 'nobody will cede the blast radius' and Bangser's 'removing humans removes learning' identify concrete, unmet prerequisites — but Ördög's context-dependence (backends, COBOL) shows the boundary is domain-specific, not absolute. The real disagreement is less about capability than about who absorbs the blast radius when an autonomous fix goes wrong.
Does the current evidence favor optimism or doubt about agentic engineering's payoff?
from: What is the future of software development in the agentic/AI age?
- Jimmy Nilsson's Post — reflections after the Thoughtworks 'Future of Software Development' retreat (Jimmy Nilsson): Optimistic: the mature, nuanced, human-centred discourse among leading practitioners is a good predictor of a healthy trajectory.
- The Future Of Software Engineering (Thoughtworks): Pessimist-realist: there is an active regression underway that most optimism ignores.
- What Survived Contact (Sam Ruby): Doubt is currently better-evidenced than hope, and that asymmetry is the uncomfortable thing to watch.
Assessment: The sharpest divergence in the corpus, because it is about the epistemic ground of every other claim. Nilsson's optimism is explicitly consensus-of-the-in-group and self-flagged as biased; Ruby and the Thoughtworks report both bring the only genuinely external evidence (DORA reversal, HBR intensification, outside surveys) — and it points the other way. On the current record, the skeptics have the stronger footing precisely because the optimistic case is methodologically weakest (a 'sample of one,' as Ruby says of his own best data). The whole cohort's cautious optimism may be an artifact of who was in the room.
Open gaps (27)
- incompleteThe article never addresses who reviews and maintains the calibration set and rubric over time, across potentially many fitness functions (boundary fidelity, semantic contracts, ADR drift, and whatever else a team adds) — this could reproduce, at the rubric-review layer, exactly the finite-senior-reviewer-capacity bottleneck the pattern is proposed to relieve at the code-review layer. This corpus already flags a structurally identical concern about spec-authoring capacity in extract-context-store-evolutionary-architecture#g1.Article: Agentic Fitness Functions: Extending Evolutionary Architecture Beyond Deterministic Rules — read next: Look for treatments of AI-eval/rubric maintenance cost at scale — how many rubrics one architecture team can realistically own and keep current.
- illogicalThe article treats judge disagreement as valuable signal of a real architectural trade-off that should always escalate to a human, but also recommends promoting recurring agentic findings into deterministic rules once the team 'agrees they represent real violations.' No criterion is given for distinguishing a finding that has become stable enough to deterministic-ize from one where persistent disagreement is itself the correct, ongoing state — the two prescriptions pull in opposite directions without a stated tiebreaker.Article: Agentic Fitness Functions: Extending Evolutionary Architecture Beyond Deterministic Rules — read next: Look for a worked example or decision procedure for when to stop escalating a recurring disagreement and instead write a rule.
- unasked questionThe essay uses the Dreyfus model to characterize agents as novice/advanced-beginner but never asks whether the Dreyfus model, developed for human skill acquisition, is even the right frame for AI systems that learn in fundamentally different ways. Agent capabilities may not map onto a linear human progression scale at all.Agents don't know what good looks like. And that's exactly the problem. — read next: Literature on AI capability evaluation frameworks that are not anthropomorphic (e.g., benchmarks, formal verification, capability elicitation research).
- implicit premiseThe argument that 'more context degrades output' treats current LLM context-handling limitations as a stable architectural constraint rather than a temporary engineering limitation. If context handling improves significantly, the 'deterministic guardrails' prescription may need rebalancing.Agents don't know what good looks like. And that's exactly the problem. — read next: Research on long-context model performance, retrieval-augmented generation, and structured context management.
- incompleteThe cost of this approach relative to its benefit is never argued. Extra interfaces, Gradle module boundaries, DI wiring, and CDK complexity have a real engineering cost, but the talk never weighs that against the — for many teams, mostly hypothetical — benefit of actually being able to switch or dual-run cloud providers, when most organizations pick one primary cloud for reasons (pricing, existing platform investment) unrelated to code portability and rarely execute a true migration even when the code is portable.Presentation: Clean Architecture for Serverless: Business Logic You Can Take Anywhere — read next: extract-outsourced-ai-still-own-the-risk#p10 raises the structurally identical unresolved premise in the AI-vendor-lock-in context ('portability is achievable enough to function as a real hedge') — worth reading together to test whether 'engineered portability' claims generalize across domains or share the same unexamined cost side.
- uninformedThe Q&A's observability answer treats 'generic logger + cloud-specific sink config' as basically solving cross-cloud observability, but doesn't address the harder problems: correlating a single business transaction's logs, traces, and metrics when parts of it run on AWS and parts on Azure, distributed tracing across clouds, or cost/retention differences between CloudWatch and Azure Monitor.Presentation: Clean Architecture for Serverless: Business Logic You Can Take Anywhere — read next: extract-infoq-data-driven-platform-engineering (platform engineering and observability federation across a real multi-cloud platform) and writing on OpenTelemetry's cross-cloud adoption as the actual mechanism for correlating traces, not just directing log lines.
- illogicalThe talk frames Terraform CDK's cross-cloud reuse as a portability win ('same lingo... different dialect'), while simultaneously showing that the actual resource definitions are provider-specific (an AWS Lambda + API Gateway + IAM permission block looks nothing like an Azure Function App block). What's actually portable is the tooling/metalanguage (write infra in Kotlin instead of HCL), not the infrastructure-as-code itself — only the business-logic layer, not the infrastructure layer, is genuinely portable. The talk doesn't name this distinction, which risks readers concluding CDKTF gives infrastructure portability it does not.Presentation: Clean Architecture for Serverless: Business Logic You Can Take Anywhere — read next: Compare with writing that distinguishes tooling-level multi-cloud consistency (shared IaC language) from artifact-level portability (the same deployable config running on either cloud) — e.g. Gregor Hohpe on multi-cloud strategy and exit costs.
- incompleteThe Amazon outage is presented as an outcome of the exact context gap this article diagnoses, but the article's own cited source (CNBC) attributes the outage to "changes merged without proper review" — a review-gate failure — not to a documented absence of persisted intent, behavior, or conformance records specifically. The causal attribution to the context gap, versus a more generic review-diligence lapse, is asserted rather than demonstrated from the available reporting.Comprehension at AI Speed: Building a Context Store for Evolutionary Architecture — read next: Follow further Amazon incident reporting or post-mortems, if published, to see whether investigators identified a missing intent/behavior/conformance record specifically, or a simpler story of a skipped approval step that a context store would not by itself have prevented.
- incompleteNo treatment of the social-and-organisational fate of the artefacts themselves. Dependency-cruiser configs, custom coupling-analyser CLIs, and imported Modularity Skill packs are all new load-bearing artefacts. Who owns them? Who updates them when the architecture should change? In the absence of an owner, the rules outlive the intent behind them and become either silently violated or silently obsolete — the classic linter-suppression-debt pathology, scaled to architecture.Three more static code analysis sensors — read next: Cutler on institutionalised overload and waste; Fearless Change (Manns & Rising) on what it takes for organisational invariants to survive; Tornhill's Software Design X-Rays on attaching social/ownership data to code-quality signals; Vlad Khononov's modularity work directly (since his Skills are now part of the harness).
- incompleteThe article treats the dependency-cruiser rule set as a substitute for a markdown structure guide, but it skips the question of whether enforcement and explanation are interchangeable. A rule that says 'clients cannot import services' enforces a constraint but does not teach why the layering exists — and the moment the constraint is wrong, the team has no shared prose to reason with. This silently relocates design intent into tooling that few people maintain, and few people can read.Three more static code analysis sensors — read next: Ousterhout 'A Philosophy of Software Design' on the role of design documents; Parnas on module specifications; Hickey 'Simple Made Easy' for the distinction between rules-as-policy and rules-as-understanding.
- incompleteHeavy reliance on Khononov's externally maintained Modularity Skills pack as the thing that makes Sensor 3 work. The article does not examine: skill-pack versioning, drift, security/supply-chain assumptions, or what happens when the skill author changes their mind. The harness now has a third-party dependency at the level of taste, not just at the level of code.Three more static code analysis sensors — read next: Khononov's Learning Domain-Driven Design and his coupling talks; literature on prompt drift; the emerging 'skills-as-dependency' discussion (Osmani's agent-skills writing).
- incompleteThe coupling-analyser is described as a vibe-coded custom CLI. The article acknowledges it would benefit from suppression of legitimate high-coupling hubs but does not engage with the more interesting question: if your coupling tool requires hand-curated exceptions for every architectural pattern, you are effectively encoding architectural intent in two places (the rules AND the exception list). At that point, why not skip the metric layer and go directly to the inferential review?Three more static code analysis sensors — read next: Tornhill, Software Design X-Rays; the dependency-cruiser community's own discussion of when DSM-style tools earn their keep.
- incompleteThe article observes that the AI modularity review found duplicate routes, scattered parameters, and misplaced auth — i.e. exactly the things a senior reviewer would find in a half-hour read of the code. There is no contrastive baseline against human-only review, against pair-review with the original implementing agent, or against a much cheaper rubric like 'review every file changed >X times in the last 30 days'. Without such a baseline, the proposition 'the review is the best available sensor' is unfalsifiable on the evidence given.Three more static code analysis sensors — read next: DORA reports' methodology on baselines; Beck on test-commit-revert and 'starving genies' as alternative scaffolds for keeping AI-edited code honest.
- incompleteNo engagement with the relationship between this approach and existing fitness-function / architecture-as-code tooling (ArchUnit, NetArchTest, ts-arch, Modulith, even Structure101). dependency-cruiser is one point in a much larger design space; treating it as 'the' dependency-rules sensor leaves the reader without a sense of where the boundary lies between custom configuration and adopting an established framework.Three more static code analysis sensors — read next: Ford/Parsons/Kua 'Building Evolutionary Architectures' on fitness functions (which she links to in the framing); ArchUnit; ts-arch.
- incompleteThe framing assumes the agent is always the implementing actor and the human (plus other agents) are the reviewers. It does not consider the inverse case — where humans implement and the AI modularity review is the rubric against which their code is judged — even though the same tooling would work. This matters because it shapes whether the harness is 'AI guardrails' or 'organisational architecture discipline that happens to use AI'.Three more static code analysis sensors — read next: Cutler on operating-system design; Beck on team practices.
- incompleteThe binary 'migrated' metric requires 100% of traffic for 30+ days, but the article never addresses what happens when a fraction of traffic must legitimately stay on the monolith forever (e.g. an old partner integration that will never be upgraded) -- is that endpoint simply never declared migrated, indefinitely, with no path to closing it out?The Hard-Stop Rule: From 3 HCM Monoliths to 120 Domain Microservices — read next: Look for practitioner writing on managing the migration 'long tail' of clients who cannot upgrade -- API deprecation and sunset strategy literature -- to see how others resolve the tension between a strict binary completion metric and an unmigratable minority of traffic.
- incompleteBoth headline numbers -- the ~70% peak-cost savings and the ~50% (4-to-6-hour) upfront tax -- are presented as stable constants across five years, but cloud pricing, wages, and story complexity plausibly shifted substantially between 2021 and 2026; the article gives no methodology or time series, only single-point averages, so a reader cannot tell whether either ratio actually held steady or drifted.The Hard-Stop Rule: From 3 HCM Monoliths to 120 Domain Microservices — read next: Look for any published time-series cost or velocity data from Paycor/Paychex, or for other companies' cost-optimization case studies with longitudinal tracking, to see whether single anecdotal ratios of this kind are durable enough to reuse as planning assumptions.
- incompleteScale dependence of pendling. The whole career story plays out inside two large Norwegian financial-services organisations (Storebrand, Fremtind) that recognise technical depth as legitimate seniority. The conversation never tests whether pendling is feasible — or how it changes shape — in small startups (no role to come back to), pure consultancies (the IC vs. leader frame may not apply), public-sector hierarchies (rigid grade structures), or US-style stock-comp tracks where stepping back is also stepping out financially.14) Øystein Ulseth pendler mellom å lede og levere — read next: Pair with Charity Majors' 'Engineer-Manager Pendulum' original essay to see her conditions for it working; pair with Will Larson on staff-engineer archetypes for the IC-track question; pair with Norwegian-public-sector accounts (NAV optimising for fast flow) for the bureaucracy edge case.
- incompleteThe people who can't pendle. Ulseth's account is sympathetic to both directions but assumes the listener has the option of swinging both ways. It does not address those who are only-leaders (lost technical currency) or only-deliverers (no taste for organisational complexity) — and whether they should be coached, paired, or left in their lane. There is a real possibility that pendling is a personality privilege as much as an organisational one.14) Øystein Ulseth pendler mellom å lede og levere — read next: Camille Fournier on technical-leadership transitions; Cutler on the costs of forcing technical contributors into managerial roles; Allen Holub on accountability and the limits of role-fluidity.
- incompleteThe architect's function is never defined. The talk asserts that architecture has not changed in its core function, only in practice — but it does not say what the function is. The closest thing to a definition is 'enabling speed and flow via loose coupling and high cohesion', which is more a goal than a function and which collapses architecture into platform engineering in some readings.14) Øystein Ulseth pendler mellom å lede og levere — read next: Vlad Khononov on coupling in distributed systems; Ruth Malan on architecture as 'the design decisions that are hardest to change'; Team Topologies for the sociotechnical framing Ulseth invokes.
- incompleteBredde/dybde sounds clean but is operationally underspecified. How does a sjefsarkitekt choose which initiatives to take as 'mine'? Ulseth nods that they should be 'both important and interesting' and that the two usually overlap — but the harder cases (important-but-boring, interesting-but-marginal) are not discussed. This is the place where pendling-by-design either works or quietly collapses into one side.14) Øystein Ulseth pendler mellom å lede og levere — read next: Cutler on how leaders allocate attention; deep-dive into 'staff-plus' patterns where senior ICs balance technical and political work.
- incompleteThe claim that AI raises the incentive to live good engineering culture is asserted but not mechanised. Continuous delivery has been well-described for 20 years and only patchily adopted. Why will AI succeed in changing this where the prior decade's tooling, DORA reports, and platform engineering did not? A causal story is missing.14) Øystein Ulseth pendler mellom å lede og levere — read next: DORA 2025/2026 specifically on AI's interaction with delivery practices; Birgitta Böckeler and Martin Fowler on AI-coding feedback loops; Kent Beck's TCR work as the practice end of the same idea.
- incompleteNo data on whether pendling actually produces better outcomes. The argument is largely 'I felt better and have heard I do better.' The episode lacks any reference to organisational research on whether engineer-manager pendulum careers correlate with better team or product outcomes — and whether the benefits go to the individual, the team, or the organisation.14) Øystein Ulseth pendler mellom å lede og levere — read next: Pragmatic Engineer / Newcomer on staff-plus role outcomes; LeadDev surveys on engineer-manager transitions; academic work on bidirectional career mobility in knowledge work.
- uninformedUlseth notes he has not yet seen conversational architecture practiced and that sociotechnical architecture is a new acquaintance — yet these are the frameworks he is now bringing into Fremtind's IT strategy. The talk does not engage seriously with the published critiques of these models (e.g. that Team Topologies under-specifies platform-team funding, or that Harmel-Law's model assumes a maturity teams may not have).14) Øystein Ulseth pendler mellom å lede og levere — read next: Andrew Harmel-Law's own book and the Architecture Decision Records literature; critical reviews of Team Topologies (Manuel Pais et al.).
- incompleteThe four-rebuilds story is reported as triumph but never costed. Destroying and rebuilding the platform architecture four times has a cost — for the consuming squads who must re-learn it, for the regulators who must re-approve it, for the institutional memory that bleeds out at each rebuild. The article reports the platform team's experience ('it worked perfectly for us') without checking the consumer side. The same testimony from the squads might read very differently.How a Culture of Data-Driven Conversations Can Support Platform Engineering — read next: Ford, Parsons & Kua on evolutionary architecture (the disciplined version of what Petean is describing). Hohpe on architecture decision records and the institutional cost of irreversibility. Naur on programming-as-theory-building — what gets destroyed in a rebuild that isn't in the code.
- uninformedThe talk asserts deployment gates catch non-conformance but never addresses what happens when an architecture is gate-compliant yet still architecturally wrong in a way the pattern didn't anticipate — a limitation the corpus has already surfaced independently for agentic fitness functions (structural conformance checks prove an import exists or a schema parses, not that the change is architecturally sound).Presentation: APIs for Agents: Rethinking API Programs in the MCP Era — read next: extract-agentic-fitness-functions-evolutionary-architecture, which explicitly separates deterministic structural gates from judgment-heavy architectural review.
- incompleteThe whole cross-retreat comparison rests on an acknowledged seam: the author read only the public summary of the earlier retreat, so he cannot separate 'the conversation genuinely grew' from 'the earlier summary simply compressed this out.' The central 'what changed' claim is offered on face value with that limitation showing.What Survived Contact — read next: Obtain the fuller record (not just the public key-takeaways summary) of the earlier Thoughtworks retreat and re-run the comparison against like-for-like source material.