Claim: the ideal PR is 50 lines long
A claim that the “ideal” pull request is around 50 lines of code, based on metrics like faster merges and fewer reverts, has triggered debate over how software changes should be structured and reviewed. Many engineers argue that line count is a poor proxy for quality, noting that real features, refactors, and tests often require hundreds or thousands of lines and that tiny PRs can fragment context, increase coordination overhead, and invite bikeshedding. The emerging consensus is that a good PR represents a coherent, reviewable unit of work that can be safely deployed, with size treated as a flexible guideline rather than a hard target to optimize or enforce.
Overall reaction to the “50-line ideal” claim
- Many see the claim as overgeneralized or even “silly” without context.
- Others think the core idea—smaller, focused PRs are easier to understand and safer—is broadly true but should be treated as a guideline, not a rule.
- Several note the article is from a company that benefits from smaller/stacked PRs, and view it partly as product advertising.
Arguments in favor of smaller PRs
- Easier to review thoroughly; less chance of rubber-stamping.
- Often correlate with fewer reverts and faster merge times in the cited data.
- Lower cognitive load for both author and reviewer; easier to schedule quick reviews during small time windows.
- Better at isolating behavioral changes, making reverts and debugging simpler.
- Help prevent “monster PRs” that frequently slip bugs and are hard to reason about.
Arguments against strict line-count targets
- Lines of code are seen as a poor proxy for complexity or value.
- Arbitrary limits (e.g., 5- or 50-line caps) can destroy context, force awkward slicing, encourage omitting tests, and make features harder to review as a whole.
- Very small PRs can cause excessive context-switching, fragmented understanding, and “death by a thousand PRs.”
- Refactors, redesigns, new subsystems, schema changes, or large test additions often legitimately span hundreds or thousands of lines.
Context, content, and “unit of work”
- Many argue the real “ideal” is: one coherent, deployable unit of behavior per PR, however many lines that is.
- Commits vs PRs: several prefer small, logical commits inside a larger PR, with clean history for reverts and archaeology.
- Some emphasize that test code should often be in the same PR; others suggest separate PRs for non-critical test additions.
Metrics, causality, and process
- Multiple commenters stress correlation ≠ causation; small PRs might just be inherently simpler/low-risk work.
- Concern that managers will Goodhart this into targets (“PRs must be ~50 lines”) detached from actual quality.
- Experiences vary widely: some teams improved reliability by enforcing smaller PRs; others found strict limits slowed delivery and worsened reviews.