Have you worked with Prometheus and OpenTelemetry?

Yes, in my Flutter projects, I have used Prometheus and OpenTelemetry for monitoring and tracing applications.

Prometheus was used to collect metrics from backend services that interact with the Flutter application. This allowed tracking API performance, errors, and response times.

OpenTelemetry was used for distributed tracing to see the chain of calls between the mobile application and the server side. In Flutter, integrating OpenTelemetry helps collect data on UI performance, network requests, and errors.

Example of integrating OpenTelemetry in Flutter:

import 'package:opentelemetry_api/opentelemetry_api.dart';

final tracer = OpenTelemetry.instance.getTracer('my_flutter_app');

void fetchData() {
  final span = tracer.startSpan('fetchData');
  try {
    // perform network request
  } finally {
    span.end();
  }
}

Thus, these tools help improve the quality and stability of applications, identify bottlenecks, and respond quickly to issues.