https://www.semicolonandsons.com/episode/production-logs-best-practices

Logs are a fundamental part of diagnosing and fixing issues in your production system. I talk about 1) the importance of having a single command to immediately tail all relevant logs; 2) the need to ensure one line of log corresponds to one event (in order to play well with unix tools); 3) how to use the timeless awk command to parse your logs; 4) the value of being comprehensive in what you log, so that you can better diagnose issues and re-run failed requests after a bug has been fixed; 5) my system for recreating entire user session journeys by parsing my logs.