IELTS Evaluator
AI band scores for IELTS writing and speaking, live as a web app with paid plans.
- Founder, architect and full-stack developer
What it is
A practice platform where IELTS candidates submit essays and recorded speaking answers and get band scores (0–9) on every official criterion, with strengths, weaknesses and next steps. It is a React web app backed by a Django API.
The problem
Candidates rarely get examiner-quality feedback between attempts, and human marking is slow and expensive. Speaking is hardest: it needs transcription and evaluation without the user waiting on a frozen page.
Architecture
Requests flow left to right. Hover a component for its role.
- React web app client, TypeScript, React Query
- Nginx edge, TLS, reverse proxy
- Django REST API service, JWT cookies, credits
- Stripe external, plans, webhooks
- PostgreSQL data
- Redis queue, Celery broker, cache
- Celery workers worker, evaluation jobs
- AWS S3 data, speaking audio
- GPT-4 and Whisper ai, scoring, transcription
Key decisions
Evaluation runs off the request path
Writing and speaking jobs go to Celery workers through Redis, so the API answers immediately and the client polls for the result instead of holding a connection open while GPT-4 and Whisper work.
Prices follow the cost of AI
Plan prices are derived from the measured GPT-4 and Whisper cost per evaluation plus a fixed margin, so a credit always covers what it costs to deliver.
Highlights
- Practice across all four IELTS modules: listening, reading, writing and speaking.
- Scores Task 1 and Task 2 writing on Task Achievement, Coherence and Cohesion, Lexical Resource and Grammar.
- Speaking answers are transcribed with Whisper and scored on fluency, vocabulary, grammar and pronunciation.
- Credit plans from a 7-day trial to annual, billed through Stripe with auto-renewal.
- Email verification, Google and Microsoft sign-in, JWT in HTTP-only cookies, CSRF protection and API rate limits.