In full
We design the audit trail alongside the schema, not stapled on before an inspection. Reconstructing history should be a query, not a project.
The Fourths · Engineering for regulated industries
Blog / Platform Engineering
Audit trails as a first-class architectural concern.
An audit trail bolted on at the end is a log file. Designed in from the start, it is a feature you can stand behind.
Platform Engineering · 7 min read · May 2026
The short version
What is wrong with a normal log?
Most logs tell you something happened. Few tell you who did it, the state before and after, and let you reconstruct it months later without a forensic exercise.
What makes an audit trail trustworthy?
Append-only, attached to every modification of regulated data, and queryable by the people who field the regulator's questions.
What is the test?
Ask "what happened to this record on this date." The answer should take seconds and need no apology.
