What I Look for When a Risky PR Lands
The article outlines the key review criteria the author applies when a high-risk pull request (PR) is submitted, focusing on aspects like correctness, security implications, test coverage, and potential side effects to ensure safe deployment.
Background
- PR stands for "pull request" — a proposed code change in collaborative software development, typically reviewed by teammates before being merged into the main codebase.
- A "risky PR" is one that touches critical systems (e.g., authentication, payments, data pipelines) or makes large, hard-to-revert changes. The author, Jake Lundberg, is a senior infrastructure engineer writing from experience reviewing such changes at scale.
- The post focuses on the **post-merge** phase — what to check *after* the PR has already been approved and merged, because some failure modes only surface in production with real traffic.
- Key items the author checks: deployment logs, error rates, latency metrics, database query performance, memory/cpu usage, and any alerting or monitoring signals that might indicate the change caused a regression.
- The mindset is that even well-reviewed code can behave unexpectedly in production, so treating post-merge as an active investigation rather than a handoff is a form of due diligence.
- This is part of a broader engineering culture around "safe deploys," gradual rollouts, and observability — not just testing in staging.