Structured Logging (ARCH8158)

Key kotlin.logging.structured-logging · Severity info · Category logging

Flags string templates / concatenation inside logger calls - the message is formatted even when the level is off and the values are not structured.

Incorrect

logger.info("user $userId logged in from $ip")

Correct

logger.info("user {} logged in from {}", userId, ip)

Fix

Use the logger’s placeholder syntax with arguments.