Comparison
Architecture decision recordvsRequest for comments
Architecture decision record
you asked why the queue was chosen and someone found a one-page file in the repository from 2023.
A short document recording one decision: the context, the options, what was chosen and what it costs. It lives with the code, is numbered, and is never edited after acceptance — a later decision supersedes it rather than rewriting history. Its value is entirely in the future: it is what stops a new team from either blindly keeping a constraint that expired or cheerfully re-making a mistake somebody already paid for.
Full entry →Request for comments
you wrote up the plan and left it open for a week so people could argue in the margins before you built anything.
A proposal circulated for comment before a decision is made, aimed at people who would otherwise be surprised. Unlike a decision record it is a live document with an audience and a deadline, and its main product is often the objections rather than the approval. It is worth distinguishing them clearly: the RFC is the conversation, the ADR is the sentence you write down afterwards.
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