I have been assigned a task to plan and implement centralised user tracking and observability system for our product. I have read about various options available but I can’t decide which will be better for our use case.

Expectations:
Logs, Traces, metrics and user activity tracking

• Alters for errors
  Automatic ticket creation by webhook or similar for uncaught exceptions
  Data visualisation or searching

TechStack:
Frontend: Svelte
Backend: Nest JS
Database: PostgreSQL
ORM: Prisma

• Docker
• Kubernates

Environments:

• Production
• Staging
• PR

Solutions Reviewed:

• Sentry
• OpenTelemetry
• Grafana
• Posthog
• prometheus

Approach:
I’m planning to use Posthog for user activity tracking, OpenTelemetry to for logs, traces and metrics, Sentry for error tracking and alerts, and Grafana for data visualisation

Questions:

• Do I need these all to achieve expectations? All seems preety much same.
• Grafana also provides alerts, Do I need sentry?
  If OpenTelemetry can collect logs, traces and metrics, Do I need sentry for error tracking?
  Where can I store the data collected by OpenTelemetry?