Logging Standards

Field Details
Status Active
Last Updated 04-22-2026

Purpose

To establish consistent logging practices that improve debugging and system observability

Scope

Applies to: All backend services, frontend applications, APIs

Does not apply to: Third-party libraries

Log Levels

Level When to Use
ERROR Something broke and needs immediate attention
WARN Something unexpected but the app continues
INFO Key business events (user created, payment processed)
DEBUG Detailed flow info — dev/staging only, never production

Rules

  • Log only required infomation and limit it to less characters. Logging too much is also not helpful
  • Never use inbuild stdout utils always use the logger
  • Never log passwords, tokens, card numbers, or PII
  • Always log at the entry point of a request and on errors
  • Include enough context to debug without opening the code
  • Debug logs should be disabled in production

What to Log

// Good examples:
log.info("Invoice created | invoiceId={} userId={}", invoiceId, userId);
log.error("Payment failed | orderId={} reason={}", orderId, e.getMessage());

// Avoid:
log.info("done");                    // lacks context
log.debug("user: " + user.toString()); // avoid string concatenation
log.info("Token: {}", authToken);      // never log sensitive data

Log Format

All logs must follow this structure (handled by the logging framework config):

YYYY-MM-DD HH:mm:ss | LEVEL | service-name | traceId | message

Example:

2024-01-01 10:32:11 | ERROR | payment-service | abc123 | Payment failed | orderId=99

Common Mistakes

System.out.println("here");           // use logger instead
log.error(e.toString());              // log message + exception separately
log.info("password: {}", pass);       // never log sensitive data

Exceptions

Debug logs may be enabled in staging environments for troubleshooting

Changelog

Version Date Author Change
1.0.0 04-22-2026 Tibin Sunny Initial version