How do I catch regressions before they reach players?

Test the areas a change affects (on real devices), monitor crash rate per version after release with alerts, and verify fixes did not regress anything, so regressions are caught before or right after they ship. Regressions come from changes breaking things that worked, and the mistakes are not testing the affected areas (so regressions ship), not monitoring per version after release (so they are not caught fast), and not verifying fixes. To catch regressions: test what a change affects, not just the change itself (a change can break related functionality), especially on real devices where regressions hide on your machine, monitor crash rate per version after release with alerts (so a regression that slipped through is caught within minutes, a crash spike or new crash on the new build, rather than from player reports days later), and verify fixes per version (confirming they did not regress anything). Per-version monitoring is the key safety net for what testing missed. Bugnet's per-version crash tracking with alerts catches a regression within minutes of shipping and verifies fixes, so regressions are caught before or right after they ship, letting you roll back or fix before they spread, rather than discovering them from a wave of player reports.

How do I know if an update introduced a regression?

Monitor crash rate and crashes per version, a regression shows as a new crash or a crash-rate spike on the new build that was not there before. The mistake is not monitoring per version, so a regression is invisible until players report it. With per-version tracking, you compare the new build against the previous one: if a crash appears on the new build that was not on the prior one, or the crash rate spikes on the new build, the update introduced a regression. This shows up fast (within minutes of shipping, if you monitor with alerts), letting you catch the regression while it has reached only a fraction of players. The new crash's stack trace and the per-version comparison point at what the update broke. Bugnet tracks crash rate and crashes per version with alerts, so a regression from an update surfaces fast (the new build's crash rate climbing or new crashes appearing), and the captured context shows what broke, so you can confirm the update introduced a regression, identify the cause, and roll back or fix it before it spreads, rather than not knowing an update regressed something until players report it days later.

Why do my fixes sometimes break other things?

Because a fix is a code change, and any change can have unintended effects, a side effect in the changed code, an interaction with other code, or a case the fix did not account for, introducing a new regression. Fixes break things for the same reason any change does: new code (even fix code) is the least-tested, can affect things beyond what it directly touches, and might not account for every case, so a fix that resolves the target issue can introduce a new bug. This is why fixes need verification, not just confirmation that they build. The mistake is assuming a fix is safe and not checking whether it regressed anything. To catch fix-introduced regressions: make targeted fixes (a narrow change has less surface area to break things), test the change and the areas it affects, and verify per version after shipping (confirm the target issue is resolved and, importantly, that no new crash appeared, which would indicate the fix regressed something). Bugnet tracks crashes per version, so after a fix you can confirm it resolved the target issue and watch for any new crash it introduced, catching a fix that broke something within minutes, so even a fix that causes a regression is caught fast and can be corrected, rather than a fix silently breaking something else and you not knowing.

Common Regression Testing Mistakes

Quick answer: The biggest regression testing mistakes are not testing changed areas, no per-version monitoring, and not verifying fixes, fix these by testing what changed and monitoring per version.

Regression testing catches when changes break things that worked, and common mistakes let regressions ship. Here are the most common regression testing mistakes and how to avoid them.

Not Testing the Areas a Change Affects

A common regression testing mistake is testing only that a change works, not that it did not break related functionality, so regressions in the affected areas ship. A change can break things beyond what it directly touches, and not testing those areas misses the regression.

The fix is testing the areas a change affects, not just the change itself, especially on real devices. Bugnet complements this by catching the regressions that slip through: it captures crashes per version, so a regression testing missed surfaces fast from real players, with the context to fix it.

Not Monitoring Per Version After Release

A second mistake is not monitoring per version after release, so a regression that slipped through testing goes unnoticed until players report it. Without per-version monitoring, regressions spread before you catch them.

The fix is monitoring crash rate per version after release with alerts. Bugnet tracks crash rate per version and alerts on spikes, so a regression surfaces within minutes of shipping, letting you roll back or fix before it spreads, the safety net for regressions testing missed.

Not Verifying Fixes Don't Regress

A third mistake is not verifying that a fix did not itself regress something, when a fix is a change that can introduce its own regression. An unverified fix might have caused a new problem while resolving the old one.

The fix is verifying fixes per version: confirm the target issue is resolved and no new crash appeared. Bugnet tracks crashes per version, so after a fix you can confirm it resolved the issue without introducing a regression, catching a fix that broke something fast.

Avoid the big regression testing mistakes: not testing changed areas, no per-version monitoring, and not verifying fixes. Test what changed and monitor per version.