TCF slot releasescaught in 0.18sautomatically.

Real-time exam-slot monitoring for TCF Canada, the French proficiency test. Six cities — Toronto, Calgary, Edmonton, Victoria, Vancouver, Winnipeg. Monthly, cancel anytime.

Start monitoring$20 CAD / month→How it works→

563Active monitors

308Slots released this week

100%Weekly detection rate

100%City monitor uptime

Live figures, snapshot 2026-09-08

TENSOR STUDIO — CASE STUDIESNº 02SAAS · MONITORING & SUBSCRIPTIONS · 2026

TCF Monitor

A bilingual subscription site and a monitoring fleet, designed and engineered end to end: 97 pages from one generator, six cities each with their own watcher.

Nº 01PAGES SHIPPED97One Python generator

Nº 02LANGUAGES2Chinese and English, hreflang paired

Nº 03CITY MONITORS6One service each

Nº 04WATCHDOG5mA cron watching the watchers

CODEEXAM CENTREMONITORSRELEASED · WKWEEKLAST ALERTSTATE

YYZToronto46325424hACTIVE

YYCCalgary8834this weekACTIVE

YEGEdmonton39this weekACTIVE

YYJVictoria31this weekACTIVE

YVRVancouver39this weekACTIVE

YWGWinnipeg31this monthACTIVE

6/6 CENTRES ONLINE · 308 RELEASES THIS WEEKLIVE FIGURES · SNAPSHOT 2026-09-08

01FRONTENDStatic site · Vanilla JS97 pages built by one Python generator, no framework
02BACKENDCloudflare Worker · D1Dashboard, subscriber accounts, alert pipeline
03MONITORSPython · systemdOne watcher per city, plus a five-minute watchdog
04PAYMENTSStripeMonthly subscriptions, sold per city

( RELEASE )

Build
Tests
Deploy
Sitemap
IndexNow

Challenge

Seats appear without warning and vanish in minutes, so the product had to notice before people do and keep noticing, unattended, for months.

What we built

A bilingual site generated from one codebase, not two
A watcher per city, each its own service
A watchdog that monitors the monitors
A retrying outbox, so a transient failure delays an alert instead of losing it
Stripe subscriptions sold per city
Sitemap and IndexNow on each release

Status

Live at tcfmonitor.com, with paying subscribers.