To monitor API uptime and alert on incidents, set up three layers of observability:

1) External availability checks

Use a monitoring tool to hit your API from outside your network on a schedule.

Check:

• GET /health or /ready
• critical endpoints like login, search, or checkout
• multiple regions if you serve global users

Alert on:

• endpoint down / timeout
• elevated latency
• non-200 responses
• SSL certificate expiry
• DNS resolution failures

Tools:

• Datadog, New Relic, Pingdom, UptimeRobot, Better Stack, Grafana Cloud Synthetic Monitoring
• open source: Prometheus + Blackbox Exporter, Checkly, k6, Playwright for synthetic flows

2) Internal service health

Expose a dedicated health endpoint that reflects service dependencies.

Example:

• /healthz = process alive
• /readyz = can serve traffic
• include checks for:
  • database connectivity
  • cache availability
  • queue/broker connectivity
  • downstream API dependencies

Keep health checks lightweight so they don’t overload production.

3) Error and performance monitoring

Track metrics and logs so you can detect partial outages.

Monitor:

• request rate
• error rate (4xx, 5xx)
• p95/p99 latency
• saturation: CPU, memory, thread pool, DB connections
• dependency failures

Use dashboards with:

• uptime %
• recent incidents
• latency by endpoint
• error budget burn

---

Alerting setup

Create alerts with severity levels:

Page immediately

• API down for 2–5 minutes
• error rate > threshold for critical endpoints
• latency above SLA for sustained period

Notify during business hours

• intermittent failures
• rising latency
• degraded dependency

Ticket / log only

• minor anomalies
• single-region blips
• warning-level saturation

Use:

• PagerDuty, Opsgenie, VictorOps, Slack, email
• route alerts by severity and service owner

---

Good alert rules

Avoid noisy alerts. Use:

• multi-check confirmation
• rolling windows
• hysteresis / cooldowns
• alert only when user-facing impact is likely

Example:

• “API down” only if 3 consecutive probes fail from 2 regions over 3 minutes
• “High latency” only if p95 > 500 ms for 10 minutes

---

Incident workflow

When an alert fires:

1. Confirm the issue with external probes
2. Check recent deploys/config changes
3. Inspect logs, traces, and dependency health
4. Mitigate: rollback, disable feature flag, fail over, scale up
5. Postmortem and add prevention

---

Recommended minimal setup

If you want something simple and effective:

• /health endpoint
• Uptime checks every 1 minute from 2 regions
• Alerts to Slack + PagerDuty
• Metrics for latency/error rate
• Dashboards for uptime and key dependencies

If you want, I can also give you:

• a reference architecture
• Prometheus/Alertmanager rules
• a Datadog/CloudWatch setup
• or a sample health check endpoint in your language/framework.