Post-incident software repair is the work done after an outage is resolved - stabilizing the system, closing the gaps that allowed the failure, and implementing safeguards that prevent the same failure from recurring.
It’s the difference between “we fixed it” and “we fixed it and it won’t happen again.”
Why It Matters
During an active incident, the goal is to restore service as fast as possible. That means shortcuts: rolling back instead of fixing forward, increasing resource limits instead of finding leaks, disabling features instead of debugging them. These are the right calls under pressure.
But those shortcuts leave technical debt. The root cause is still in the codebase. The monitoring gap that let the failure go undetected for an hour is still there. The missing test that would have caught this in CI is still missing.
Post-incident repair closes that debt before the next incident.
What Post-Incident Repair Involves
Root cause fix - If the incident was resolved with a rollback or temporary workaround, the underlying code issue still needs to be fixed properly. This means writing the fix in a branch, adding tests that cover the failure scenario, deploying to staging, and releasing to production with monitoring.
Monitoring improvements - Most production incidents expose a gap: something failed for longer than it should have because there was no alert. Post-incident repair includes configuring the specific alerts that would have caught this failure earlier.
Test coverage for the failure scenario - The failure scenario that just hit production is now a known case. Adding a test for it means it can’t silently reappear in a future deploy.
Runbook updates - If your team had to figure out the diagnosis from scratch, that knowledge should be documented. A runbook for “database connection pool exhausted” means the next engineer who sees this symptom doesn’t start from zero.
Architecture changes - Some incidents expose structural problems: no circuit breaker on a third-party dependency, no connection pooling for background workers, multi-tenancy isolation enforced inconsistently. These require larger changes, but they belong in the post-incident backlog.
The Post-Incident Review
Post-incident repair starts with a post-incident review (also called a postmortem). This is a blameless examination of:
- What happened and when (timeline)
- Why it happened (root cause analysis)
- What was done to resolve it
- What will prevent recurrence
The output is a written document and an action list with owners and timelines. Without this document, post-incident repair tends to stall - the urgency passes, the context fades, and the same conditions that caused the incident remain.
Timeline for Post-Incident Work
- Post-incident review: within 24-48 hours of resolution, while context is fresh
- Immediate fixes (monitoring, temp workaround replacement): within 1 week
- Structural improvements (test coverage, architecture changes): within 2-4 weeks, prioritized against other work
We Can Help
If you’ve recently recovered from a production incident and want to make sure it doesn’t happen again, we can conduct a post-incident review and implement the fixes. We’ve worked on post-incident repair for Rails applications across a range of failure types.
Contact us to discuss your incident, or read about our emergency software services.