Summary

Walketalk is the LMS of an English academy that until then only taught in person, one student at a time. The platform did not digitize an existing process: it built the online side of the business end to end, from the sale to the classroom.

One system covers all three sides of the operation. Students buy, book, and study. Teachers publish their availability, teach, and leave a record of every class. Admins enroll students into recurring slots, reassign teachers, grant make-up classes, handle refunds, and watch the business metrics.

The classroom

• A CEFR placement test that positions the student before the first class.
• Self-correcting grammar exercises and videos assigned by the teacher, student by student.
• A written summary from the teacher after each class, visible to the student.
• A full class history, with balance and expiry dates always in sight.

Bookings and payments

• Session packages or single classes paid by card, with tax calculated at checkout.
• Enrollment in a fixed weekly slot with a specific teacher, plus one-off bookings on aggregated availability: the student picks a time slot, not a teacher.
• Every class publishes itself to Google Calendar, with a Google Meet link and an email invitation.
• Credit-based balance with per-credit expiry and FIFO consumption, three-day rescheduling windows, and automatic right-of-withdrawal eligibility.

Technical decisions

The platform is the single source of truth: Google Calendar is used purely as a publishing channel, while availability, enrollments, and bookings are computed in the database. Everything is stored in UTC with real multi-time-zone support (teachers set availability in their local time, students read it in theirs), and every automated process is idempotent: unique indexes on weekly class generation, deduplication of payment webhooks, and retries with backoff on Google API calls.