Indie SaaS KPI Design and Measurement: MAU, ARR, NPS, and Churn

Without clarity on what to measure, your improvement loop never runs.

KPI Selection Principles

North Star Metric (pick exactly one)
  ↓
Leading KPIs (3–5 metrics)
  ↓
Lagging KPIs (ARR/Churn → review monthly)

For indie SaaS, the North Star is usually Weekly Active Users (WAU) or
number of times users succeed (e.g., "tasks completed", "articles published").
ARR and MRR are outcomes, not goals.

MAU / WAU / DAU — Your "Active" Definition Is Everything

-- MAU: Monthly Active Users
SELECT COUNT(DISTINCT user_id) AS mau
FROM user_events
WHERE created_at >= date_trunc('month', NOW())
  AND event_type IN ('page_view', 'task_create', 'task_complete');

-- WAU (last 7 days)
SELECT COUNT(DISTINCT user_id) AS wau
FROM user_events
WHERE created_at >= NOW() - INTERVAL '7 days';

-- Retention: active last month AND this month
SELECT COUNT(DISTINCT curr.user_id) AS retained
FROM (
  SELECT DISTINCT user_id FROM user_events
  WHERE created_at >= date_trunc('month', NOW())
) curr
JOIN (
  SELECT DISTINCT user_id FROM user_events
  WHERE created_at >= date_trunc('month', NOW() - INTERVAL '1 month')
    AND created_at < date_trunc('month', NOW())
) prev USING (user_id);

Recording events from Flutter:

await supabase.from('user_events').insert({
  'user_id': supabase.auth.currentUser?.id,
  'event_type': 'task_complete',
  'properties': {'task_type': 'daily_check'},
});

ARR / MRR — Essential If You Charge

MRR = paid users × monthly ARPU
ARR = MRR × 12

Monthly churn = (paid end of last month - paid end of this month) / paid end of last month
NRR = (retained + upsell - churn) / last month's MRR

Healthy benchmarks for indie/small SaaS:

• Monthly churn < 5%
• NRR > 100% (upsells offsetting churn)
• Free-to-paid CVR > 3%

NPS — "Would You Recommend?" Is a Leading Indicator

NPS = % Promoters (9–10) - % Detractors (0–6)
Target: > 0 (40+ is best in class)

Send one email 30 days after sign-up via Resend API:

// Edge Function: send-nps-survey
const score = parseInt(payload.score);
await supabase.from('nps_responses').insert({
  user_id: payload.user_id,
  score,
  comment: payload.comment,
  responded_at: new Date().toISOString(),
});

Dashboard Design

Weekly: WAU, new signups, task completion rate
Monthly: MAU, MRR, churn rate, NRR, NPS

Supabase + Metabase (self-hosted) works well. The Supabase Studio SQL editor is
often enough for indie scale. Write events continuously to user_events — you
can always aggregate anything later.

Summary

North Star    → WAU or success-action count (industry-dependent)
Leading KPIs  → retention rate / feature usage / NPS
Lagging KPIs  → MRR / churn rate / ARR
Iron rule     → define "active" before writing any query

The act of measuring alone surfaces improvement ideas. Build the recording
infrastructure first — analysis follows naturally.