Sample application / Production

Northwind Labs

Which channels make money, and which bugs get in the way?

2026-10-04 – 2026-11-02
Last 30 days · UTC · Read only

$490/mo across 3 paying customers affected

Checkout is failing for people who already pay.

Visitors

30,773

Daily uniques summed over 30 days

Signups

662

Completed signup events

Monthly recurring revenue

$18,420

Current active subscriptions · USD

Visitors over the last 30 days

Where paying revenue comes from

First-touch channel, joined by person to successful payments in the selected 30 days. MRR is the current subscription snapshot.
Channel	Visitors	Signups	Paying customers	Revenue	MRR
Organic search	10,770	231	48	$7,200	$6,800
Developer communities	6,154	132	36	$5,400	$4,800
Direct	7,693	165	29	$4,350	$4,100
Paid search	3,692	79	12	$1,800	$1,600
Social	2,464	55	8	$1,200	$1,120

Errors, ordered by money at risk

At risk is current MRR from affected paying customers, not a prediction of churn or proven lost revenue.

Issue	Status	Events	People	Paying	At risk
app/checkout/summary.tsx:41	Unresolved	84	61	3	$490/mo
POST /api/billing/session returned 502lib/billing/session.ts:68	Investigating	31	27	1	$190/mo
Chart could not load its dataapp/dashboard/chart.tsx:22	Unresolved	12	8	1	$99/mo
Loading help chunk failedapp/help/page.tsx:12	Resolved	9	9	0	$0/mo

Unresolved / Checkout

TypeError: Cannot read properties of undefined (reading 'plan')

84 events · 61 people · $490/mo · 3 paying customers

At risk means affected subscription MRR. It does not mean this revenue was lost.

Stack summary

PlanSummary (app/checkout/summary.tsx:41)
CheckoutPage (app/checkout/page.tsx:18)

Hypothesis: selectedPlan is undefined while billing data loads.

Replay summary

0:00 — Opens /pricing
0:41 — Chooses the Team plan
1:58 — Opens /checkout
2:36 — Clicks Continue three times
2:37 — TypeError; checkout stops

Demonstration summary. Input values masked; no recording is loaded.

Paying customers affected

All names, companies and subscriptions are fictional.

Person	Company	First-touch channel	MRR
Ada Okafor	Cedar Studio	Organic search	$190
Ravi Patel	Paperlane	Developer communities	$190
Mira Lindqvist	Fieldwork	Direct	$110

Fix with Claude Code or Cursor

Copy the evidence into your coding agent. It can inspect your repository and open a fix for review.

Investigate the fictional Northwind Labs checkout issue for 2026-10-04 through 2026-11-02 (UTC).

TypeError: Cannot read properties of undefined (reading 'plan')
Stack: PlanSummary (app/checkout/summary.tsx:41) -> CheckoutPage (app/checkout/page.tsx:18).
84 error events, 61 people affected, 3 paying customers with $490/month in current MRR. This is affected subscription MRR, not proven lost revenue.
Replay summary: /pricing -> /checkout -> Continue clicked three times -> TypeError; input values masked.
The selected plan can be undefined while billing data loads. Inspect this hypothesis in the repository; do not treat it as a confirmed cause. Add a loading guard and reproduce the checkout path. Run the relevant checks and open a pull request for review. Do not deploy or change production flags.

This is demonstration data; no live workspace, credentials or customer records are included.

Revenue by channel

Organic search produces the most paying revenue here. Developer communities bring fewer visitors but more revenue than Direct.

First-touch channel, joined by person to successful payments in the selected 30 days. MRR is the current subscription snapshot.
Channel	Visitors	Signups	Paying customers	Revenue	MRR
Organic search	10,770	231	48	$7,200	$6,800
Developer communities	6,154	132	36	$5,400	$4,800
Direct	7,693	165	29	$4,350	$4,100
Paid search	3,692	79	12	$1,800	$1,600
Social	2,464	55	8	$1,200	$1,120

Revenue is successful payments in the selected period, before refunds, fees or tax. Channels use the first recorded source on the person; this sample is not a causal attribution model.