reactioncommerce/reaction: technical due diligence, read from its repository

The median source file here is 33 lines. 4 files exceed 1,000 lines, the largest being 2,549. Size is not a defect on its own — some problems genuinely live in one place — but these are where merge conflicts, review fatigue and single-owner knowledge concentrate, and they are the first thing that slows an inheriting engineer down.

Deleted lines per line added rose from 0.89 to 1.13 between the first and second halves of this history. Rework is normal and often healthy, but a rising ratio means an increasing share of the team's time is spent replacing code that already exists rather than building what does not. Whether that is deliberate repayment or churn is a question for the team.

The code is pinned to Node.js 18 (end of life 2025-04-30). None of these receives security fixes any more; the first stopped on 2025-04-30. Moving off an unsupported runtime is rarely a one-line change, so a buyer should ask whether the upgrade is planned and what it touches.

5 third-party CI actions are referenced by a tag or branch rather than a commit, so they run whatever that tag points to on the day. Tags have been moved to malicious commits in real supply-chain attacks, and a piped script is whatever the server returns that minute. Pinning to a commit is the fix, and it is small.

Nothing in the service initialises an error reporter (Sentry, Rollbar, Bugsnag, Honeybadger or an APM agent). An exception in production reaches a person only if someone is reading the logs, which usually means a customer reports it first.