A Calm, Step-by-Step Approach to a Production 500 Error

A sudden spike of HTTP 500 errors is stressful, but the investigation almost always follows the same path. Work through it in order and resist the urge to guess.

1. Establish scope

• Is it every request or one endpoint?
• Every user or a subset?
• When exactly did it start?

The start time is your most valuable clue: compare it with deployments, configuration changes, certificate expiries and upstream incidents.

2. Find the first real error

Search the application logs for the earliest stack trace around the start time. Later errors are often side effects. Look for the exception type, the failing line and the input that triggered it.

ERROR POST /api/orders -> 500
KeyError: 'customer_id'

An error like this points to a changed payload or contract rather than an infrastructure fault.

3. Check what changed

Most incidents are caused by change: code, configuration, data, dependencies or traffic. If a recent deployment lines up with the start time, a rollback is usually the safest first mitigation.

4. Mitigate first, then fix

Restore service with the lowest-risk action available, then take time to understand the root cause properly and add a test or alert so it cannot silently recur.

5. Write it down

A short timeline — what happened, how it was detected, what fixed it, what will prevent it — turns a bad day into a visible contribution.

Need a second pair of eyes during an incident? See our production troubleshooting support.