Performance Degradation & Timeouts Since Django & Stack Upgrades
We’ve been experiencing significant performance issues and intermittent timeouts on our app ever since we upgraded:
- Django from v2.x to v4.2
- Heroku stack from 20 to 22
Prior to these upgrades, our response times were solid and timeouts were virtually non-existent. Over the past week, we’ve noticed: a) Longer page-load times (up to 5–10 seconds on endpoints that were previously sub-second) b) Occasional H12 request timeout errors during moderate traffic spikes c) Increased memory usage and dyno restarts that correspond to those timeouts
We’ve checked our application logs, continue to optimize database queries, and temporarily scaled up our dynos, but the root cause still seems tied to the upgrades themselves.
I) Have you experienced similar behavior when upgrading to Django 4.2 or the Heroku-22 stack? II) Any learnings, recommendations or best practices for tuning our configuration to restore performance to pre-upgrade levels?
If there are known workarounds — whether it’s specific buildpack versions, config vars, or tweaking dyno settings — any guidance would be helpful.