Topics / Building software

How is AI used in code review?

AI that reviews code changes, finds problems before merge, or picks the human reviewer.

33 passages from 13 organizations; 23 checked against the source.

What the record shows

Uber and Cloudflare run AI review across most code changes

An Uber staff engineer said its uReview tool analyzes over 90% of the roughly 65,000 diffs (pull requests) landed each week, and engineers who interact with it mark 75% of its comments as useful. Cloudflare, which sells AI infrastructure, says it had 100% AI code reviewer coverage across all repos on its standard CI pipeline over 30 days. Klarna says 80% of its engineers and data scientists had connected an AI copilot that can create and review code as of June 2025.

From Sonal Mahajan (Uber), Cloudflare and Klarna.

Accounts differ on whether a person makes the final review call

Warp, which sells AI tooling, says its reviewer agent surfaces issues and a human makes the final call on quality and correctness. An Uber distinguished engineer described automated agents handling code review with human reviews or escalations. A Shopify principal engineer lists automated PR review as a mode that often runs with no human in the loop.

From Warp, Uday Kiran Medisetty (Uber) and Burke Libbey (Shopify).

These summaries are this site's, not quotations. Each was checked by a second reader, who confirmed it says no more than the passages it cites. The organizations' own words follow.

93% of our PRs are now automatically handled by Review Buddy so that the highest quality engineers are spending time on the 7% of PRs that truly matter,

Geoff CharlesChief Product Officer (CPO) · Executive, Ramp

Talk: What product looks like when coding is solved | Geoff Charles (Ramp CPO), Lenny's Podcast (YouTube channel); Geoff Charles's talk at the Lenny and Friends Summit, recorded 2026-09-10, September 25, 2026, at 09:34.

  • 93% function agent share, share of PRs, as of 2026-09. Level not stated

Checked against the source [ Grade B ] Said in the last year Ramp: $1.5 billion revenue, annualized revenue (ARR), by early June 2026 Passage page

We're now seeing agentic code reviews that look at code changes through a series of different lenses. In the past, it would have been impractical for a cloud infrastructure engineer and a security engineer to review every single code change. With agents, that becomes possible.

Venkat VenkataramaniVP of Engineering, Applied Infra · Leader, OpenAI

Press report: Inside OpenAI's agentic software factory, The Pragmatic Engineer, September 15, 2026, at 2. Death of the IDE & pull requests. Reported by Gergely Orosz.

Checked against the source [ Grade C ] Said in the last year OpenAI: $20 billion revenue, ARR, 2025 Sells AI tools Passage page

a growing share of sessions aren’t initiated by humans, but by automated managed agents handling code review, self-healing CI failures, completing E2E PRs with visual validation, triaging on-call alerts, debugging incoming bugs, and handling a variety of code maintenance tasks with human reviews/escalations.

Uday Kiran MedisettyDistinguished Engineer · Practitioner, Uber

Post: Running a Software Factory Efficiently at Uber Scale, Uber engineering blog, August 27, 2026.

Checked against the source [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

if this is an autonomous diff coming from Minion, we want to give a human reviewer some confidence that this diff has gone through a lot of self-improvement already

Uday Kiran MedisettyDistinguished Engineer · Practitioner, Uber

Talk: Agentic SDLC at Uber: Building Blocks for Uber's Software Factory (talk, AI Engineer World's Fair 2026), AI Engineer (conference organizer) YouTube channel, August 21, 2026.

Checked against the source [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

We are definitely still bottlenecked on reviews, especially for things that are touching some architecture pieces. And it's actually more subtle than just being bottlenecked on review, … we can carve out time differently. It's … bottlenecked on human ability to even fully conceptualize what we're doing.

Mike KriegerHead of Anthropic Labs · Leader, Anthropic

Context. Answering a question from the host on whether code review is a bottleneck and whether code could be merged without a person looking at it.

Interview: How Anthropic Builds: Lessons from Labs, AI Engineer (YouTube), July 2, 2026, at 10:13.

Checked against the source [ Grade C ] Said in the last year Anthropic: $47 billion revenue, run-rate, May 2026 Sells AI tools Passage page

actually talked to Claude about the code and say, all right, these are the questions that I would have. Can you go investigate it? So it is kind of … code review, but still human-driven, and for the really important ones. And for the ones that are cosmetic visual changes, it's much more like we'll fix forward if we need to fix forward.

Mike KriegerHead of Anthropic Labs · Leader, Anthropic

Context. Continuing his answer on review. The sentence before this passage, on not reviewing every line of a pull request, is not quoted because the two passes disagreed on its wording.

Interview: How Anthropic Builds: Lessons from Labs, AI Engineer (YouTube), July 2, 2026, at 11:13.

Checked against the source [ Grade C ] Said in the last year Anthropic: $47 billion revenue, run-rate, May 2026 Sells AI tools Passage page

So one of the reasons we built … artifacts that we shipped a couple of weeks ago was partially for that, which is you would send somebody a PR, and then they'd be like, I don't know, man, this is like 2000 lines of code. It looks like code to me. And what we started doing instead is sharing much more like, here's a … artifact. Here's the explanation. Here's the intention of the change. Here's the trade-offs that were made.

Mike KriegerHead of Anthropic Labs · Leader, Anthropic

Context. Continuing his answer on review bottlenecks. The product name before 'artifacts' is rendered unclearly in the recording's transcripts, so the passage is cut around it.

Interview: How Anthropic Builds: Lessons from Labs, AI Engineer (YouTube), July 2, 2026, at 10:30.

Checked against the source [ Grade C ] Said in the last year Anthropic: $47 billion revenue, run-rate, May 2026 Sells AI tools Passage page

You get a pretty high degree of confidence on merge. Today, almost a fifth of all the pull … are merged without any human review or without any human testing. … that is a number that we care a lot about and want to bring higher and higher, of course, within the guardrails of producing really high quality code.

Daksh GuptaCo-founder · Executive, Greptile

Talk: AI-Generated Code Is Already Competing With Human Code, AI Engineer (YouTube), September 27, 2026, at 11:50.

  • 20% share prs merged without human review, as of the talk (almost a fifth). No person in the loop

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

every time there's a pull request, we have a swarm of agents. And they go and look at every file that's changed, every file that's related to the files that change to figure out if there's bugs. And it also spins up your code in a sandbox, … dependencies, spins up local host, clicks around to try to break things, mocks inputs, and everything else to figure out if the code is broken.

Daksh GuptaCo-founder · Executive, Greptile

Talk: AI-Generated Code Is Already Competing With Human Code, AI Engineer (YouTube), September 27, 2026, at 00:27.

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

So then I started tracking the counts of P0s, P1s, and P2s in all of these changes. And interestingly, once again, there was not that much of a difference. In fact, three out of the four agents that we tested performed better than humans in terms of the rate at which … were producing P0s. They were producing fewer P0s than humans were. Similarly, the case with P1s and P2s. Broadly speaking, human-generated PRs were about equal in quality to … PRs based on this data.

Daksh GuptaCo-founder · Executive, Greptile

Talk: AI-Generated Code Is Already Competing With Human Code, AI Engineer (YouTube), September 27, 2026, at 07:07.

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

And so I started tracking the number of iterations, the number of review rounds between when the pull request was opened and when it was merged. Sure enough, very little difference. … Once again, very little if any statistical difference between human-generated and AI-generated pull requests in terms of how many iterations before they're ready to merge.

Daksh GuptaCo-founder · Executive, Greptile

Talk: AI-Generated Code Is Already Competing With Human Code, AI Engineer (YouTube), September 27, 2026, at 07:57.

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

This tool basically visualizes our dependency graph internally with some external dependencies as well, … But what's more interesting is we can go build CLI tools that guarantee that certain invariants can't be broken. And what this does is when Claude builds a new package or adds a dependency that's leaky, we now have CI/CD changing or a simple git commit history that tells us exactly where things break. And by this, we're actually able to make our architecture change. We haven't changed our architecture in the last three or four months.

Vaibhav GuptaCo-founder and Chief Executive · Executive, Boundary (BoundaryML)

Context. Gupta is describing how the team keeps the BAML code base from drifting when engineers do not review each other's code.

Talk: Fighting Slop with Slop, AI Engineer (YouTube), July 31, 2026, at 4:05.

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

We do no code reviews. We require every engineer to work on things in parallel, and we have no standardization how people do AI.

Vaibhav GuptaCo-founder and Chief Executive · Executive, Boundary (BoundaryML)

Context. Opening of a conference talk by the chief executive of Boundary, the company that builds the BAML programming language, on how its team works.

Talk: Fighting Slop with Slop, AI Engineer (YouTube), July 31, 2026, at 0:26.

Checked against the source [ Grade B ] Said in the last year Sells AI tools Passage page

I think we found that the state-of-the-art in December was you can probably, run this for about two weeks. By the end of those two weeks, you’d find that, hey, you want to, change the color of a button. Well, it turns out this button is implemented in, 10 different places, and they, have All these different variations, and oh, you forgot one of them, and actually it’s a slightly different color in one spot.

Walden YanCo-founder and Chief Product Officer · Executive, Cognition

Context. Yan was describing an internal experiment building real products by auto-merging AI-written code with no code review, to see how many weeks it could run before the codebase became unmanageable.

Podcast: The Age of Async Agents: Cognition's Walden Yan and OpenInspect's Cole Murray, Latent Space, May 28, 2026, at 00:44:21. Reported by Swyx.

Checked against the source [ Grade C ] Said in the last year Sells AI tools Passage page

Back in 2024, we were seeing that engineers would get their first review within three hours. Now, in 2026, that has grown to nine hours, in addition to all of the volume changes. So in short, code review is now the bottleneck that we are running into.

Will BondStaff Engineer, AI Foundations team, Development Platform organization · Practitioner, Uber

Context. Will Bond is describing a metric Uber tracks, the time to a first review of a pull request.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 01:05.

  • 3 hours first review time 2024, 2024
  • 9 hours first review time 2026, 2026

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

Currently, we still have humans approving the code, but we see a short path in the near future to a percentage of our code landing automatically, having automatic approvals, right?

Will BondStaff Engineer, AI Foundations team, Development Platform organization · Practitioner, Uber

Context. Will Bond is describing where Uber expects code review to go as it moves to an agentic software development life cycle.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 11:39.

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

One of the biggest learnings in this process was like the model doesn't know that it's wrong. It always confidently says 100% sure that, yeah, this is the review for your code. Go ahead. But we saw that, no, it actually needs a lot of guidance from the teams, because each team has its own style guide, its own patterns or … anti-patterns that they want to look for.

Ameya KetkarSpeaker, AI Engineer World's Fair 2026 (job title not stated) · Practitioner, Uber

Context. Ameya Ketkar is describing what Uber's team learned while adding observability and evaluation to its uReview code-review agent.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 06:35.

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

One thing that we learned is that actually writing the skill was very easy, like teams just very quickly wrote a skill by asking Claude to write one, go over my previous PR reviews and write me a skill, but the hard part was how to run these skills at scale with consistent quality and low cost, and that required a lot of iterations, not only from the [uReview] team side, but also … for each team who was trying to write these rules.

Ameya KetkarSpeaker, AI Engineer World's Fair 2026 (job title not stated) · Practitioner, Uber

Context. Ameya Ketkar is describing how Uber's teams wrote their own code-review skills for uReview.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 09:44.

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

But rather than killing the outer loop, I think that we believe and the industry has just started to really kind of coalesce on this idea that … really expanding the outer loop. Rather than removing humans from the code review process, we are moving their responsibilities up a layer.

Will BondStaff Engineer, AI Foundations team, Development Platform organization · Practitioner, Uber

Context. Will Bond is closing the talk on what happens to human reviewers as agents write and review more of the code.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 13:43.

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

Uber spent the time to invest in building an in-house solution due to some of the constraints that we have. One of those is we currently use [Phabricator] and have for a long time and are in the process of migrating to GitHub. Most of the solutions do not provide support for [Phabricator].

Will BondStaff Engineer, AI Foundations team, Development Platform organization · Practitioner, Uber

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 01:22.

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

[uReview] does … around 25,000 comments a week, and we get 10% of them actually get some feedback … We also saw that the overall address rate was around 67%, and almost three quarters of the high severity issues were usually addressed by the developers

Ameya KetkarSpeaker, AI Engineer World's Fair 2026 (job title not stated) · Practitioner, Uber

Context. Ameya Ketkar is reporting results for uReview, Uber's code-review system. The address rate is how often a developer acts on a comment, as he defined it earlier in the talk.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 10:13.

  • 25,000 comments ai review comments, per week. AI assists a person
  • 67% review comment address rate, as of the talk. AI assists a person

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

we saw that against like a very naive implementation, our costs were down by 60%, and our quality and our accuracy was up by around 70%.

Ameya KetkarSpeaker, AI Engineer World's Fair 2026 (job title not stated) · Practitioner, Uber

Context. Ameya Ketkar is summarizing the effect of the observability and evaluation work on uReview, Uber's code-review system.

Talk: Building uReview, Uber's Multi-Agent Code Review Engine (talk, AI Engineer World's Fair 2026), AI Engineer (YouTube), August 28, 2026, at 10:50.

  • -60% ai review cost change, against a naive first implementation
  • 70% ai review quality change, against a naive first implementation

Not yet checked [ Grade B ] Said in the last year Uber: $52 billion revenue, FY2025 Passage page

engineers don't trust AI opinions. They just trust clear findings tied to standards that we … agreed upon. … it stopped sounding more like, maybe this is a problem and started sounding more like this violates a standard that we actually care about.

Rajesh BhatiaSenior Director of Engineering, Cloudflare · Leader, Cloudflare

Context. Describing early misses with Cloudflare's internal AI code reviewer, before the team tied its findings to machine-readable engineering standards.

Talk: From Assisted to Delegated: Cloudflare's AI Engineering Stack (interview, Background Agents Summit 2026), Ona (YouTube), May 6, 2026, at 26:40.

Not yet checked [ Grade B ] Said in the last year Cloudflare: $2.2 billion revenue, FY2025 Sells AI tools Passage page

Our Network Firewall team audited rampartd using a multi-agent consensus process where every requirement was scored COMPLIANT, PARTIAL, or NON-COMPLIANT with specific violation details and remediation steps reducing what previously required weeks of manual work to a structured, repeatable process.

CloudflarePublished by the organization itself (post), no named author

Post: The AI engineering stack we built internally, on the platform we ship, Cloudflare blog, April 20, 2026, at Act 3, "Engineering Codex: engineering standards as agent skills".

Not yet checked [ Grade B ] Said in the last year Cloudflare: $2.2 billion revenue, FY2025 Sells AI tools Passage page

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