Agentic AI and Code Reviews
Zach Davis, Michelle Gill, Elisabeth Hendrickson, Angie Jones, Sha Ma, Randy Shoup, James Wickett Β· pdf Β· 2026-09-14 source β Reader π₯οΈ
Agent SecurityCoding AgentsContext EngineeringFeedback LoopsMulti-Agent OrchestrationPull Requests & Async Code ReviewSpec-Driven DevelopmentTrust
As AI agents generate code faster than human attention can scale to review it, code review must be reorganized from a single human merge-time gate into a layered, risk-tiered verification system β deterministic checks, continuous author/review-agent loops, structurally independent adversarial review, and specialist multi-agent review β with human judgment deliberately reserved for intent, strategic risk, and accountability rather than mechanical inspection, and every automated decision recorded as a durable, auditable artifact.
practical Β· mixed β A named pattern language (explicitly modeled on Christopher Alexander) argued into existence through empirical motivation (review-capacity bottleneck), illustrated with three detailed organizational case studies (Block, Cloudflare, DryRun Security), and closed with direct recommendations to engineering leaders β practical throughout, with expository pattern definitions and narrative case evidence.
Structure
| Part | Role |
|---|---|
| Introduction and Defining Code Review β establishes the capacity crisis and a precise three-part definition of code review | context / framing |
| The Value of Code Reviews β cites empirical studies showing review's value extends well beyond defect-finding to maintainability and knowledge sharing | evidence / stakes |
| How Does Agentic Code Review Work β reframes trust as earned, not assumed, and lays out the generationβverificationβreleaseβlearn loop with risk-tiered human involvement | thesis statement |
| Patterns for Agentic Code Review (nine named, composable patterns: Small Incremental Changes, Shift Left, Design for Verification, Deterministic Engineering Practices, Context Engineering, Continuous Code Quality Loop, Adversarial LLM Review, Multi-Agent Reviews, Spec-Driven Development) | core content / toolbox |
| Case Studies (Block, Cloudflare, DryRun Security) β show three independently-arrived-at versions of the same layered system under real organizational constraints | evidence / validation |
| Concluding Thoughts β reframes the shift as organizational redesign (responsibility, risk allocation, role blurring, audit records) rather than a tooling upgrade | conclusion |
Key terms
- Code review Pull Requests & Async Code Review
An examination of source code by an entity that is not the author, with the intention of making a judgment that leads to an action (merge, reject, or feedback) β deliberately defined so the 'entity' may be an agent and so review is distinguished from casual reading. - Shift Left
Moving deterministic verification (formatting, type errors, dependency policy, schema checks) as early as possible β into the IDE, pre-commit, or pre-push β so that only genuinely judgment-requiring concerns reach review. - Context Engineering (as applied to review) Context Engineering
Deliberately making a codebase 'agent-ready' by turning it into a repository of operational knowledge, architectural intent, and historical decisions (AGENTS.md, knowledge graphs, indexed incident/postmortem history) β not an optional add-on but infrastructure every other review pattern depends on. - Adversarial LLM Review
Structural independence between the agent that writes code and the agent that reviews it (different model, different session with no shared context, or structured adversarial prompting) β modeled explicitly on GANs (generator/discriminator) and Zero Trust (explicit verification, least privilege). - Multi-Agent Reviews
Decomposing review into specialist agents (security, performance, compliance, standards, correctness, operational readiness) coordinated by a triage agent (selects which specialists run) and a coordinator agent (deduplicates and synthesizes findings into one structured assessment) β an ensemble-learning analogy applied to review.
Propositions
- explicitManual, human-only code review cannot scale with AI-generated code volume, but the solution is neither simply adding more human reviewers nor removing humans entirely β it is redistributing review into a layered, continuous, risk-tiered system (deterministic checks, author/review-agent loops, adversarial and multi-agent AI review, selective human judgment).conf: highextendsAgentic Code Review Β· p12 β Both describe the human moving 'up a level' from reading every diff to owning accountability/judgment; this paper operationalizes that shift into nine named, composable patterns and three real deployments.
- explicitcorroboratedCode review's value substantially exceeds defect-finding: citing a Microsoft study and two further empirical papers, most review activity addresses maintainability, style, alternate-solution discovery, and knowledge sharing β 'evolvability' risk β rather than catching functional bugs, which means any redesign of review must preserve these non-defect functions, not just correctness checking.conf: highsupports βBugs in Large Language Models Generated Code: An Empirical Study Β· p8 β If a meaningful share of LLM bugs require semantic judgment rather than pattern-matching against known human mutant operators, this reinforces the claim that review's value (and now testing's value) lies beyond simple defect-pattern matching β in catching maintainability, intent-fit, and non-obvious category errors.
- explicit'No human in the loop' should be a deliberate, risk-and-evidence-justified configuration choice, never a default, and every agentic review decision must produce a durable, inspectable record (what was evaluated, under which policy, with what confidence, by whom) to preserve organizational accountability.conf: highextendsAgentic Code Review Β· p13 β Directly answers the 'borrowed confidence' risk of a closed self-reviewing loop sharing blind spots: this paper's requirement for durable, inspectable audit records plus risk-tiering is the proposed structural remedy.
- explicitAI code generation, left to its defaults, produces large synthesized change sets that overwhelm human and AI reviewers alike, so keeping changes small becomes more important under AI, not less β because large diffs are harder for AI reasoning to evaluate too, not only for human attention.conf: highsupportsGitHub Brings Stacked Pull Requests to Public Preview Β· p2 β Both identify shrinking change-set scope (stacked/incremental PRs) as the lever that reduces the review bottleneck, rather than simply demanding reviewers process more per unit time.
- explicitdevelopedReviewing code with the same model/session/assumptions as the agent that wrote it reproduces the author's own blind spots; adversarial review requires structural independence (a different model, a context-isolated session, or structured adversarial prompting) modeled on GAN generator/discriminator dynamics and Zero Trust's explicit-verification and least-privilege principles.conf: highsupportsAgentic Code Review Β· p10 β Corroborates the recommendation to run heterogeneous/independent reviewers: the cited experiment found minimal overlap between four review tools' findings, which is the concrete evidence this paper's Adversarial LLM Review pattern argues for by analogy.extends βHow I write software with LLMs Β· p5 β Where the other document frames adversarial, structurally-independent review theoretically (via the GAN/Zero-Trust analogy), this article supplies a concrete, named production workflow (architect/developer/1-3 reviewers, escalation on disagreement) that instantiates the same principle.
- explicitAgents lack the tacit institutional memory (hallway conversations, accumulated intuition) that lets human reviewers catch things like an undocumented client dependency; organizations that skip deliberate Context Engineering find their agentic-review failures trace to missing organizational memory, not insufficient model intelligence.conf: highsupportsGit real: AI agents arenβt just for solo developers anymore Β· p3 β Both treat remembering organizational decisions across people and sessions as a team-scale requirement that a personal-scale harness or review setup doesn't need, reinforcing Context Engineering as infrastructure, not configuration.
- explicitdevelopedSpec-Driven Development relocates the primary review gate from implementation to the plan: once intent is reviewed and hardened up front, code review's job shifts from trying to catch what went wrong to verifying that a trusted, already-approved plan was faithfully executed β because by the time code exists, the most consequential (and hardest to reverse) decisions have already been made.conf: highextends β10 Things Developers Want from their Agentic IDEs in 2025 Β· p7 β This piece names developers' desire for spec-driven artifacts as durable, session-surviving contracts; the other extraction specifies the mechanism β review relocates from implementation to the plan once the spec is hardened.
- implicitAcross three case studies (Block, Cloudflare, DryRun Security) operating under very different constraints (internal AI-first scale-up, CI-native infrastructure vendor, AI-native security startup), each organization converged independently on the same layered-escalation shape β shift-left, small increments, continuous author/reviewer agent loop, then adversarial or multi-agent review β because the same underlying constraint (code generation is cheap, organizational attention is not) forces the same architecture regardless of starting point.conf: medium
- explicitcorroboratedAs agentic systems absorb mechanical code generation and review, professional role boundaries blur (developer/tester, and now architect/developer/product manager), and the decisive remaining human skill shifts toward writing precise specifications, designing risk-tiered verification policy, and exercising judgment on ambiguity and strategic fit β not toward reviewing more code faster.conf: highsupports βBugs in Large Language Models Generated Code: An Empirical Study Β· p10 β The taxonomy's split between prompt-caused categories (Misinterpretation, Missing Corner Case β failures of ambiguous intent) and generatively-caused categories (Hallucinated Object, Wrong Attribute) gives empirical grounding to the claim that the decisive human skill is writing precise specifications and judging ambiguity, not mechanically re-checking code.
Arguments
Human-only, single-gate code review cannot be preserved as AI accelerates code volume; it must be redistributed into a layered, continuous, risk-tiered verification system. strength: high
Explicit premises:
- Senior engineers already received dozens of merge-review requests per day before full agentic adoption.
- AI further multiplies code volume and generation rate.
- Human code review persists today because of three interlocking forces β trust, compliance, and accountability β not because it is uniquely effective at finding defects.
Implicit premises:
- Whatever replaces single-gate human review must preserve review's non-defect functions (knowledge sharing, risk triage, maintainability signal), not just correctness checking.
- Neither extreme β status quo manual review, nor fully autonomous review with no human β satisfies trust, compliance, and accountability simultaneously.
Inferences:
- The resulting system (deterministic shift-left + continuous author/reviewer loop + adversarial/multi-agent AI review + human escalation for ambiguity and accountability) is close to a forced architecture given these constraints, not a stylistic preference.
- Organizations that try to resist the change (pure manual review) or go fully autonomous (no durable accountability trail) are both predicted to fail β illustrated by Block's initial failed homegrown AI review and by every case study's retention of a human escalation path.
Independent, structurally adversarial review is necessary wherever an author agent and a reviewer agent might otherwise share assumptions, because shared-context review cannot catch shared blind spots. strength: medium
Explicit premises:
- GAN theory: a discriminator with independent parameters gives an honest signal about a generator's weaknesses precisely because it does not share the generator's training.
- Zero Trust's explicit-verification and least-privilege principles: nothing is trusted by default, and each check gets only the minimum context it needs.
- Case evidence: Block's local adversarial agent and DryRun's 'exploitability test' both implement independent evaluation in production.
Implicit premises:
- Model- or session-level diversity reliably produces non-correlated error profiles in practice (assumed by analogy to GANs/Zero Trust, not independently measured within this paper).
- The cost of a second, independent review pass is justified for the risk tier it's applied to.
Inferences:
- Adversarial review should be risk-tiered β reserved for security-sensitive or complex-logic changes β rather than applied uniformly, given the explicit cost/latency tension the paper itself flags.
- As model diversity in an organization's toolchain narrows (e.g. everyone standardizes on one vendor's model), the value of this pattern should degrade, though the paper does not draw this inference itself.
Narratives
- At Block, agent-generated draft PRs sat untouched because the engineer who had delegated the work to an agent no longer felt the same ownership over it β exposing that 'generating code is cheap, but organizational attention is not.'
β Supports the central thesis that the crisis is organizational-attention scarcity, not code-generation capability, and motivates why the response had to be a system (shift-left, stacked small PRs, continuous loop, agent-reviews-agent) rather than simply asking humans to review faster. - DryRun Security's early multi-tenant security incident β customer data accessible across tenant boundaries, discovered shortly after entering beta in 2023 β forced the company to encode what had been a near-miss into a permanent, machine-checkable policy rather than letting it remain tribal knowledge.
β Supports the Context Engineering proposition: shows concretely how an institutional lesson that would normally live 'only in memory, Slack threads, or tribal review habits' gets converted into durable, agent-retrievable organizational knowledge. - Cloudflare's CI-native reviewer processed 131,246 review runs across 48,095 PRs in one month, producing only 1.2 findings per review on average β a deliberately low number, interpreted by Cloudflare as evidence the system prioritizes signal over noise.
β Supports the proposition that risk-tiered, signal-disciplined review can operate at real organizational scale, and illustrates why developer trust in automated review depends on avoiding noise as much as on catching real issues.
Questions addressed
- β
Can we trust an agent's judgment in code review?
Reframed rather than answered yes/no: the right question is how to structure processes so trust is earned (through evidence, risk-tiering, and durable records) rather than assumed or denied outright. - β
Does removing humans from code review eliminate the review bottleneck?
No β it relocates the bottleneck upstream (to specifying intent precisely) and downstream (to managing risk and impact after release); the authors explicitly warn that 'removing that human checkpoint only shifts the bottleneck.' - β
Is there one correct architecture for agentic code review that all organizations should adopt?
No β explicitly rejected; the patterns are framed as an independently composable toolbox, not a maturity ladder, because organizations vary in criticality, regulation, and risk tolerance. - β
Can generic, context-free AI reviewers substitute for human review of architecture and cross-system impact?
No β both Cloudflare and Block explicitly identify architectural judgment, cross-system impact, and subtle concurrency bugs as areas where AI reviewers remain weaker than humans. - β Can smaller or less-resourced engineering organizations afford the Context Engineering, Multi-Agent Reviews, and operational-reliability investment (retries, circuit breakers, model failback) this pattern language recommends?
Gaps
- incompleteAll three case studies are well-resourced, AI-forward organizations (Block at 3,500 engineers with 90% daily AI tool usage; Cloudflare operating at web infrastructure scale; DryRun Security built AI-native from day one). The paper never addresses whether a smaller, legacy-constrained, or less-funded team can afford the Context Engineering and Multi-Agent Reviews infrastructure it recommends, or what a minimal-viable version of the pattern language looks like.
Read next: Look for case studies or guidance from smaller teams or resource-constrained organizations adopting agentic code review, to see which patterns remain accessible without Block/Cloudflare-scale investment. - incompleteThe Adversarial LLM Review pattern assumes different models, sessions, or prompts reliably produce non-correlated blind spots, but the paper never reports a direct measurement of this within its own case studies (e.g., actual overlap/divergence rates between reviewer configurations on the same code) β it argues the claim by analogy to GANs and Zero Trust rather than demonstrating it empirically.
Read next: Look for direct empirical studies measuring overlap between different AI code-review tools/models on the same findings set, to test whether model diversity reliably produces complementary (not just different) coverage. - incompleteThe paper names role blurring (developer/tester, architect/developer/product manager) as a consequence of this shift but does not explore team-structure implications: whether this favors smaller cross-functional teams over specialized roles, how career ladders change when junior engineers no longer accumulate manual-review reps, or how interpersonal trust between humans on a team is affected when most review traffic is mediated by agents rather than colleagues reading each other's code.
Read next: Team-topology and career-development literature on what happens to junior-engineer skill formation and team trust when agent-mediated review replaces most human-to-human code review.closed byHead of Claude Code: What happens after coding is solved | Boris Cherny β Gives a concrete, affirmative answer to one of the three sub-questions this gap names as unexplored: role blurring does favor smaller, cross-functional teams over specialized roles, as shown by the Claude Code team's own structure (every role codes, roughly 50% overlap between engineering/product/design, with Boris predicting the title 'software engineer' itself may disappear). The gap's other two sub-questions β career-ladder effects on junior engineers and interpersonal trust effects of agent-mediated review β remain unaddressed by this interview and are carried forward as this extraction's own gap.
Closes gaps elsewhere
- Agentic Code Review Β· g4 β Partially operationalizes 'human on the loop': Cloudflare's risk-tiered review (lighter review for small changes, full specialist stack for large or security-sensitive ones) plus explicit approval policies (approve-with-comments vs. block-merge vs. human break-glass override) give a concrete selection rule for which changes get human eyes, and Block's practice of reserving humans for 'ambiguity, risk, system impact, product intent' gives a rule for what stays human. Still no numeric sampling-rate formula or representativeness guarantee, so the gap narrows rather than fully closes.
- From Async Code Reviews to Co-Creation Patterns Β· g2 β Directly engages the audit/compliance/regulated-industry framing that gap flagged as missing: DryRun Security's SOC 2-driven tenant-isolation controls and the paper's closing argument that agentic systems can produce a durable, queryable record of 'which policies were applied, how evaluations were conducted, and why decisions were made' β a potentially stronger audit foundation than traditional human review, provided the records are treated as durable artifacts rather than transient logs.
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