Quick answer: Replay files let engineers reproduce bugs deterministically. A replay-driven repro system that takes a replay file and replays it through the game beats manual reproductions.
Replay-based repro is the most-reliable. The work is upfront; the payback is forever.
Capture deterministic replay
Record inputs, RNG seeds, network packets. Reading them back reproduces the exact session.
Player upload at bug report
SDK attaches a replay file to the bug report. Engineer plays back; bug reproduces.
Per-bug replay archive
Each bug stores its repro replay. Future regressions tested against the archive.
Replay framework
Replays as test cases. CI runs them. Regressions caught at PR time.
“Replays are the gold standard for reproduction.”
If your game can support deterministic replays, the bug-fixing acceleration is significant. The investment is months; the payoff is years.