A customer called to say OTPs weren't reaching them. We checked the logs. Every request came in, every SMS went out, the provider said delivered. Nothing looked broken. So we asked for a screen recording. What followed was two days of back and forth, guessing at timestamps, and jumping between two tools that don't share a clock. We got there in the end, but it should not have taken that long. That's the part that stuck with me. The replay showed what the user did but didn't know what it called. The traces showed the calls but didn't know what the user did. The answer was sitting between the two tools, and finding it was manual work every time. So Syncline puts them together. Video, backend trace, and the SQL, all on one scrubber. Drag to a moment and you see what the user did and what your server did at the same time. They're matched by trace ID, not by comparing timestamps and hoping. Your backend doesn't need a Syncline SDK. If you already run OpenTelemetry, you point OTEL_EXPORTER_OTLP_ENDPOINT at us and you're done. It's open source and you can self-host the whole thing.

Syncline

Every layer of your stack, folded onto one timeline.

Every layer of your stack, folded onto one timeline.