Four apps,one source of truth.

Staff, teachers and parents all change records. When something goes wrong, the business needs to know who changed what, and when.

A single hook captures each record before it changes, stores only the fields that changed, and writes a readable message with the actor, role and origin — without slowing the request. An hourly job archives old logs to cold storage once the collection grows, never touching recent history.

Families agree to weekly slots, but billing, attendance and payouts need real dated classes.

On the first of each month, a scheduled job turns every confirmed weekly slot into dated classes in one batched pass, skipping anything already in the past.

Parents are billed per completed class; teachers are paid per student at hourly and half-hour rates, with penalties.

Monthly jobs build invoices from completed classes with duplicate-billing guards and price teacher payslips line by line. PDFs render in queued workers, and staff release payouts in batches with Excel exports.

An SOS from a class, a reschedule or a support reply has to reach the right person immediately.

Real-time channels are split per role and per user, so each app only receives the events meant for it.