Product Analytics

We recommend PostHog for product analytics across web and mobile applications. PostHog provides event tracking, funnels, retention, cohorts, session replay, feature flags, and experiments in one platform.

Why PostHog

• Multi-platform: Official SDKs for Next.js (web) and Expo (React Native)
• Generous free tier: 1M events, 5K recordings, 1M feature-flag requests per month at no cost
• Full product analytics: Funnels, retention, cohorts, user paths, A/B testing
• Cloud or self-hosted: Start with PostHog Cloud; self-host when required
• Open source: MIT license, transparency, no vendor lock-in

PostHog Cloud Pricing

Free Tier (No Credit Card)

The free tier resets every month. Most companies stay within these limits. See PostHog pricing for full details.

Usage-Based (Beyond Free Tier)

Pay only when you exceed free limits. You can set billing limits per product to avoid unexpected costs. Rates start at roughly $0.00005/event for product analytics.

Integration

Web (Next.js)

• Use posthog-js (or posthog-node for server-side events)
• Defer loading with next/dynamic so analytics do not block the UI
• See Vercel React skill: load analytics after hydration

Mobile (Expo)

• Use posthog-react-native
• Peer deps: expo-file-system, expo-application, expo-device, expo-localization
• Wrap the app with PostHogProvider

Events to Track

• Page/screen views (often auto-captured)
• Key actions: signup, feature usage, conversions
• Custom properties for segmentation (e.g. plan, source)

Self-Hosting

When data must stay on your infrastructure:

• Hardware: ~4 vCPU, 16 GB RAM, 30+ GB storage (e.g. Hetzner VM)
• Stack: Docker Compose (PostHog, ClickHouse, Kafka, Redis, PostgreSQL, MinIO, Caddy)
• Domain: A record for Let's Encrypt SSL

See PostHog self-host docs for setup. Note: paid-plan features (e.g. advanced experiments) are Cloud-only.

Related Documentation

• ADR 011: Product Analytics - Decision record and alternatives considered
• Logging - Server and client logging (distinct from product analytics)