Monitoring Sentry Datadog

Recommendation: Start with Sentry (fast setup, free tier). Add Datadog when you need metrics/dashboards.

Sentry Quick Setup (Python)

# pip install sentry-sdk
import sentry_sdk

sentry_sdk.init(
    dsn=os.environ["SENTRY_DSN"],
    traces_sample_rate=0.1,
    environment=os.environ.get("ENVIRONMENT", "production"),
)

Sentry Quick Setup (Node.js)

// npm install @sentry/node
const Sentry = require("@sentry/node");

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  tracesSampleRate: 0.1,
  environment: process.env.ENVIRONMENT || "production",
});

Key Metrics to Track for Gemini Apps

Implementation Steps

1. Create Sentry project at sentry.io (or self-hosted)
2. Install SDK and initialize in app entry point
3. Add DSN to environment — Secret Manager or platform env vars
4. Tag requests — Add user context, request IDs
5. Set up alerts — Error spike, latency threshold
6. (Optional) Add Datadog — Install agent, configure APM

Common Mistakes

• traces_sample_rate=1.0 in production — Sample at 0.1 or lower to control costs
• Missing environment tag — Always set environment to distinguish staging/production
• No source maps (Node.js) — Upload source maps for readable stack traces
• Ignoring Gemini API errors — Catch and report google.api_core.exceptions explicitly