Post by **Rachel Laycock**, CTO of **Thoughtworks**, published on **September 2, 2026** on *Rachel's Ramblings*, the martinfowler.com section she runs, roughly **8,000 characters**. The text is a **deliberate response** to [[houck-dx-what-are-code-reviews-for-2026-08-05]], following a public disagreement between the two authors on a **Code Remix** panel hosted by **Moderne**. Laycock accepts Houck's quantified diagnosis (+**106%** lines per diff at **Meta**, +**64%** median PR size on the DX side) and the list of non-defect-finding functions of review, then shifts the question: *« why are we waiting until code review to do all of those things? »* (A) The guiding principle is the shortening of feedback loops learned at Thoughtworks — if feedback has value, don't remove it, move it closer to the decision it informs. Each function attributed to review is reassigned upstream: exploring alternatives before implementation, knowledge transfer through **pair programming**, collective ownership through **mob programming** and team design sessions, architectural alignment through shared design followed by **fitness functions**, and automation of everything deterministic — *« We really shouldn't still be arguing about whitespace in 2026. »* (B) Exception-based review replaces systematic review: a fundamental architectural change, a sensitive security boundary, a large blast radius, an unfamiliar area of a critical system, or simply a team's declared lack of confidence. (1) Automating review with an agent that mimics the human reviewer is dismissed as *« automating the ceremony rather than questioning why the ceremony exists »*. (2) Houck's cognitive debt is acknowledged as real, but the mandatory PR is judged a weak defense: *« We need engineers to understand systems, not diffs. »*
#code review#exception-based review#pull request
Rachel Laycock · CTO de Thoughtworks · sur *Rachel's Ramblings* (martinfowler.com).
Issue of the **Engineering Enablement** newsletter from **DX** signed by **Brian Houck**, published on **August 5, 2026**, approximately **13,000 characters**. The text opens with a quantified observation: at **Meta**, significant lines per diff merged by a human increased by **106%** in one year and diffs per developer per month by **51%**, with more than **80%** of this growth coming from agentic AI, while the share of diffs reviewed within 24 hours declines; DX's analysis for its part measures a median pull request size up **64%**, while developers want to devote about **7%** of their time to review. (A) Before handing review over to AI, Houck reframes the usage question: *"What problem was code review solving before AI arrived?"* If the answer is defect detection, full automation becomes inevitable; the **Bacchelli & Bird** study (*Modern Code Review*, ICSE 2013) shows that defect-related comments account for only **14%** of comments actually written. (B) Part of the burden is *self-inflicted*: the 2016 Microsoft study of **911 developers** already identified turnaround time, review size, and understanding the motivation for the change as the top three obstacles, and only **26%** still wrote a detailed description. (1) **RADAR** at Meta serves as the reference deployment for risk stratification. (2) Three ordered moves: fix the fundamentals, design AI around human judgment, protect what review invisibly produces. The corpus already includes [[monperrus-end-of-code-review-agents-supersede-2026-06-11]], which pushes automation to the point of replacement, and [[laycock-thoughtworks-reviewing-all-this-code-2026-09-02]], the direct response to this text.
#code review#code review#review queue
Brian Houck · signataire de l'édition · sur la newsletter Engineering Enablement de DX ; fonction non affichée par la page.