Most expensive infrastructure decisions are made in a pull request where nobody sees the price. Adding a cost diff to Terraform PRs moves the conversation to the moment it is cheapest to change. This guide covers setup, usage estimates, thresholds and the limits of estimates.
Many developers want to contribute to open source and stall at the first step. A practical path from choosing a project and an issue to reproducing the bug, following CONTRIBUTING rules, making a small change, writing the pull request, handling review and DCO or CLA requirements.
Most review comments are about naming and style, while the bugs walk past. How we review for correctness instead: follow the data, probe edge cases and error paths, look for races and trust boundaries, keep PRs small and hand style to machines.