CSB — School Operations Platform

Problem

The school needed one system for its academic and accounting operations: every change traceable, existing spreadsheet data imported safely, and official documents produced in Bengali.

Solution

Built a NestJS modular-monolith backend with a consistent API contract, Prisma middleware that records an audit entry for every data change, bulk Excel/CSV import with a dry-run mode, and Playwright-based PDF generation with Bengali font support. A Next.js admin app and a Flutter parent app run on the same API.

System architecture

1. Modular monolith: each school domain (academic, accounting) is its own NestJS module behind one API.
2. One response contract for every endpoint: success and error envelopes plus consistent pagination.
3. Prisma data layer with middleware that writes an audit record for every mutation.
4. Clients: a Next.js admin web app and a Flutter companion app for parents, both on the same API.
5. Deployed with Docker behind Nginx.

Backend logic

• Audit logging lives in the data layer, so no endpoint can change data without leaving a record.
• Bulk Excel/CSV import runs as a dry run first, reporting problems before anything is written.
• PDF documents are rendered with Playwright and Chromium, with Bengali fonts embedded.
• Predictable error and pagination formats keep the web and mobile clients simple.

Tech stack

Outcome / impact

• Academic and accounting work runs on one system.
• Changes can be traced after the fact through the audit trail.
• Parents get a mobile app on the same data as the admin team.

Result: One auditable platform for the school's academic and accounting work, with web and mobile clients on a single API.

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