SaaS Logging: Structured Logs and What to Actually Track

Logs are your SaaS’s forensic toolkit. The better your logs, the faster you resolve incidents, discover bugs, and win legal/compliance battles. Here’s your real-world action guide for next-level logging in .NET SaaS (2026+).

1. What to Log (and Why)

• Errors, exceptions, and slow/failed requests—with full request context/correlation ID
• Security-critical: logins, permission changes, admin actions, failed access attempts
• Billing and business events: new charges, plan changes, refunds, user deletions
• Infrastructure: deployment, scaling, DB failover, backup result
• Compliance/audit: PII/role/plan accesses, data exports/changes

2. Structured Logging: JSON, Not Strings

• Use Serilog, NLog, or Microsoft.Extensions.Logging with JSON or NDJSON formats
• Enrich logs with request/user/tenant IDs, trace context
• Forward logs to ELK, Seq, Loki, or cloud search/alert engine
• Mask/redact secrets, compress data, apply GDPR log deletion policy

3. Implementing in .NET

• Set up logging in Program.cs, DI for per-request state/log context
• Structure logs at Information, add specifics at Warning/Error/custom event
• Don’t log sensitive token/password data, and rate limit “chatty” logs in prod
• Sample config (Serilog in appsettings.json/code)

4. CodeBlock DevKit: Logs-as-Framework

CodeBlock DevKit provides structured logging by default: JSON output, admin dashboards, summary/search for founders, compliance aids, and GDPR-compliant erasure.

SaaS Logging Launch Checklist

• All key operational, error, business, and compliance events covered
• Logs structured, enriched, and forwarded to dashboards/search
• PII/secrets masked or excluded
• GDPR/retention windows, export/delete policy live
• Alerts and review processes documented for team/support

Explore more:

• SaaS Monitoring: What Logs, Metrics, and Traces You Actually Need