English Global Express — API backend for an online language school

An online English school needed a backend that would handle three distinct roles — administrator, teacher and student — each with their own dashboard, permissions and data access. The school was growing, and the existing setup of spreadsheets and messengers could not scale: homework got lost, file sharing was chaotic, and there was no single place to track student progress.

• teachers needed to assign homework, attach files and review submissions — all in one place;
• students needed a personal space with their schedule, homework history and uploaded materials;
• the admin needed to manage groups, assign teachers and monitor overall activity;
• the frontend team was building in React/Next.js and needed a clean, documented REST API to work against.

A RESTful API on ASP.NET Core with a clear separation of concerns: Identity handles registration and login, JWT tokens carry role claims, and every endpoint is guarded by policy-based authorization.

• JWT authentication with refresh tokens and role-based access (Admin, Teacher, Student)
• Homework management: create, assign, submit and grade — with file attachments on both sides
• File upload service with size and type validation
• Group and classroom management: timetables, student lists, teacher assignments
• Entity Framework Core with SQL Server, migrations and seed data for quick local setup

• The frontend team received a documented API and integrated it without back-and-forth — contracts were agreed upfront via Swagger.
• Three roles, three dashboards, one API: each user sees only what belongs to them.
• Homework flow — from assignment to submission to grading — replaced a chain of messages and shared drives.
• The architecture is ready for growth: adding new entities (e.g. quizzes, payments) is a controller and a migration, not a rewrite.