📋 Observability + Analytics · Cheat Sheet · v1 · pin tab
See Your App · tactical reference.
5 rules · 4 layers · 8 prompts · the 6 morning numbers · the 5 crisis checks · the 5 Stripe events that wake you up.
🏆 5 golden rules · pin forever
Memorize these.
1 · You can't fix what you can't see. Instrument BEFORE you scale.
2 · 5 events > 50. Track few things well. Add as you grow.
3 · Errors silently kill conversion. Sentry is non-negotiable.
4 · Watch session replays. 10 min of replays beats 10 hrs of guessing.
5 · Make money feel real. Wire Stripe events to wake you up.
🏗 The 4 layers · 4 free tools
What watches what.
| Layer | What it sees | Tool | Free tier |
|---|
| 1 · ERRORS | Crashes · exceptions · slow loads · failed API calls · rage clicks | Sentry | 5k errors/mo · 50 replays/mo · 1 user |
| 2 · PRODUCT | Events · funnels · session replays · heatmaps · A/B tests · feature flags | PostHog | 1M events/mo · 5k replays/mo · unlimited team |
| 3 · INFRA | Web Vitals · traffic · build time · DB queries · auth events | Vercel + Lovable + Supabase | Built in · already paid · just open the tab |
| 4 · REVENUE | MRR · ARR · churn · failed payments · disputes · LTV | Stripe | Built into Stripe · webhooks free |
⚡ 8 prompts · the workshop kit · in run order
Each has a gold copy button on its slide.
⭐ Phase 1 · DECIDE what to track
P01 · 5 must-watch metrics for your stage (pre-install · 5 min) — north-star + 5 metrics tailored to your stage. Panel: Casey Winters + Lenny Rachitsky + April Dunford.
P02 · Pick your observability stack (pre-install · 5 min) — 3 stacks ($0 / $50-200 / $500+ MRR) with the install order. Panel: Charity Majors + David Cramer + James Hawkins.
🛠 Phase 2 · INSTRUMENT in 30 min
P03 · Sentry · 10-min install + first error (Act 3 · slide 21 · Exercise 1) — install · capture test error · session replay enabled · alert rules. Panel: David Cramer + Mitchell Hashimoto + Charity Majors.
P04 · PostHog · 10-min install + first funnel (Act 4 · slide 27 · Exercise 2) — install · 5 events firing · 1 funnel live · session recordings + flags configured. Panel: James Hawkins + Casey Winters + Lenny Rachitsky.
P05 · Stripe → Slack/email alerts (Act 6 · slide 37 · Exercise 3) — webhook deployed · 5 events wired · "🎉 someone paid" + "😱 someone churned" pings. Panel: Patrick Collison + Justin Welsh + Will Larson.
📊 Phase 3 · USE DAILY
P06 · Build your morning dashboard (Act 7 · slide 40 · Exercise 4) — single URL · 6 cards · 5-min daily check. Panel: Edward Tufte + Stephen Few + Justin Welsh.
P07 · Weekly KPI auto-digest (Act 9 · slide 49) — every Sunday 9am · "win / worry / fix" email. Panel: Lenny Rachitsky + Justin Welsh + Stephen Few.
P08 · Crisis prompt · "what broke?" (Act 9 · slide 50 · use whenever) — calm methodical 5-step triage. SAVE THIS PROMPT. Panel: Charity Majors + Will Larson + Tanya Reilly.
☀️ Your morning dashboard · 6 numbers in 5 min
Tomorrow 9am. Every day.
1 · Visitors today
Vercel Analytics · top of page · up or down vs yesterday?
2 · Signups today
PostHog · 1 number · did we add users?
3 · Activation 7d
PostHog funnel · % of signups that hit your "aha"
4 · New MRR today
Stripe · how much $ did we add?
5 · New errors
Sentry · last 24h · anything BROKEN?
6 · 1 session replay
PostHog · daily UX gut-check · 2 min
Bookmark + add to phone home screen. The morning ritual that separates "I think we're growing" from "we grew 4% w-o-w, here's the 3 issues."
🚨 Stripe events that wake you up
5 events · 5 alerts.
| Event | What it means | Action | Priority |
|---|
| checkout.session.completed | 🎉 New customer subscribed | Celebrate. Optionally welcome email + onboard. | HIGH |
| customer.subscription.deleted | 😱 Customer churned | Email them today. Ask why. Save-attempt sequence. | HIGH |
| invoice.payment_failed | ⚠️ Card declined | Email customer within 1 hour. Stripe retries auto. | MEDIUM |
| charge.dispute.created | 🚨 Chargeback initiated | Respond in Stripe within 7 days w/ evidence. | HIGH |
| invoice.paid | 💚 Recurring payment landed | Quiet log. Update MRR. Optional thank-you ping. | LOW |
Tonight: wire the first 2 (success + churn). Add the rest next week.
🆘 When something breaks · the 5-step triage
Save P08. Paste in panic.
- 1SENTRY · sort by "first seen, last 24h" · ANY new error types?
sentry.io/issues?statsPeriod=24h
- 2DEPLOY HISTORY · any deploy in the window when symptom started? Vercel · Lovable · or
git log · candidate to roll back?
- 3SUPABASE LOGS · any RLS errors / DB timeouts / auth failures?
supabase.com/dashboard/[project]/logs
- 4POSTHOG FUNNEL · drop-off spike in same time window? Which step? Which segment?
- 5STRIPE WEBHOOKS · any payment failures / webhook delivery issues?
stripe.com/dashboard/webhooks
You'll catch 90% in 90 seconds. The other 10% are slow leaks the weekly digest catches.
💰 Free tier limits · when to upgrade
When you'll graduate.
| Tool | Free tier | Upgrade trigger | Next tier $ |
|---|
| Sentry | 5k errors/mo · 50 replays/mo · 1 user | ~$5k MRR or 2+ teammates | $26/mo (Team) |
| PostHog | 1M events/mo · 5k recordings · 100 flags | ~$10-20k MRR (many never upgrade) | ~$0.00031/event PAYG |
| Vercel Analytics | 2.5k events/mo | ~1k visitors/day | $20/mo (Pro · 100k events) |
| Supabase | 500MB DB · 1GB storage · 50k MAU | ~500 active users | $25/mo (Pro) |
| Stripe | Free forever | n/a | 2.9% + 30¢ per transaction |
For Build Sprint: all free tiers cover you to ~$5-10k MRR. Total stack cost at Day 30: $0/mo.
📋 Post-workshop checklist · do TONIGHT
Before tomorrow 9am.
- Sentry installed · first test error captured · alert rule enabled
- PostHog installed · 5 events firing · 1 funnel live
- Stripe webhook deployed · 🎉 + 😱 alerts pinging Slack/email
- Vercel Analytics enabled · 1 click in Vercel dashboard
- Morning dashboard URL bookmarked on phone home screen
- Weekly digest cron deployed · test email landed in inbox
- Posted to cohort chat · screenshot of first event/dashboard · tagged @meganmartinsone · #30DaystoShip
By Sunday's Public Pitch Day: walk in with REAL metrics. "We have X users · Y% activation · Z MRR. Here's the funnel."
📣 Sunday · Public Pitch Day at NS
Bring real numbers.
📅 When
Sunday · all day
NS Library
📊 Bring
Live dashboard
Real metrics · session replays · Stripe MRR · weekly digest
🎬 Film crew
NS official crew
Interviews · B-roll · be camera-ready
The flex: investor asks "how's it going?" — you don't say "great!" You pull up your dashboard. Numbers. Replays. Confidence.