Definition
Code review culture describes the norms that govern how changes enter Bitcoin Core. The project treats careful, independent review as its most valuable and scarcest resource. Project documentation states plainly that in-depth reviewing and testing are the bottleneck, and that reviewing is the most effective way for a new contributor to help. Writing code is comparatively easy; convincing skeptical reviewers that consensus-critical code is correct is the hard part.
A shared review vocabulary
Reviewers communicate in compact terms. A Concept ACK endorses the goal of a change; an Approach ACK endorses the method; a tested or untested ACK (tACK/utACK) reports that the reviewer examined the code and, where stated, ran it. A Nit flags a minor, usually non-blocking issue. A NACK is a substantive objection that must carry a technical rationale to count. This shared language makes the state of a proposal legible at a glance.
No coding by committee
There is no formal vote and no committee that ratifies changes. Maintainers read the review thread, weigh objections on technical merit and reviewer expertise, and merge only when rough agreement exists. The culture deliberately rewards adversarial scrutiny over speed, which is appropriate for software that secures a monetary network and cannot easily be patched after the fact.
This culture is the practical face of lazy consensus and is enforced day to day by each Bitcoin Core maintainer.
In Simple Terms
Code review culture describes the norms that govern how changes enter Bitcoin Core. The project treats careful, independent review as its most valuable and scarcest…