WnSOJ - Work and Solve online judge!

WnSOJ is a platform where you can solve programming and math tasks, learn new algorithms and concepts and find job. Platform offers effective testing system, categorized problemset, editorials and solutions, submissions, job search, users and statistics.

Check it out at wnsoj.xyz!

Architecture

• Backend: Django + Django REST Framework (DRF)
• Judge workers: Postgres-backed JudgeJob workers using isolate
• Realtime: FastAPI (ASGI) SSE service in realtime_service/ (streams verdict/progress from Redis pub/sub)
• Frontend: Next.js (App Router) in frontend/ (Tailwind UI)
• Auth (browser): Django session cookies (sessionid) + CSRF (csrftoken) — no JWT, no localStorage
• Internal API: Django /api/* is not public and is protected by a shared secret header (X-Internal-API-Key)
  • Next.js server-side requests include the internal key automatically
  • Browser-side mutations go through Next.js route handlers under /backend/*, which proxy to Django and attach the internal key
• Streaming (verdicts): Browser connects to Next.js /backend/submissions/*/stream (SSE), Next proxies to the FastAPI realtime service

Getting Started

Backend (Django)

1. Clone:

git clone https://github.com/spike1236/WnSOJ.git
cd WnSOJ

2. Create a virtualenv (recommended) and install Python deps:

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

3. Install runtime requirements:
   • g++ (with -std=c++23 support; GCC 13+ recommended)
   • python3.12
   • isolate (cgroups v2-based)
4. Create .env from .env.template and fill in values:
   • SECRET_KEY, DEBUG, DB settings
   • INTERNAL_API_KEY (shared with Next.js)
   • REALTIME_ORIGIN (Next.js -> FastAPI realtime service, default http://localhost:9000)
   • CSRF_TRUSTED_ORIGINS (include your local/prod frontend origin, e.g. http://127.0.0.1:8081 if you proxy through nginx)
5. Apply migrations (and optionally create an admin user):

python3 manage.py migrate
python3 manage.py createsuperuser

6. Run:

python3 manage.py runserver
python3 manage.py run_judge_worker --worker-id judge-local-1 --box-id 1
uvicorn realtime_service.main:app --host 127.0.0.1 --port 9000

Open http://127.0.0.1:8000 (Django-rendered pages) or start the Next.js frontend (below).

Frontend (Next.js)

In a separate terminal:

cd frontend
npm install
BACKEND_ORIGIN=http://localhost:8000 REALTIME_ORIGIN=http://localhost:9000 INTERNAL_API_KEY=dev-secret npm run dev

Open http://localhost:3000.

Notes:

• INTERNAL_API_KEY must match the Django INTERNAL_API_KEY in .env.
• REALTIME_ORIGIN should point to the FastAPI realtime service.
• REALTIME_REDIS_URL is the realtime Redis setting.
• In dev, Next.js will proxy /admin/, /static/, /media/ to Django. Browser API calls use /backend/* route handlers.

Deployment

See DEPLOY.md.

About Project

Problems and submissions

Platform provides an extensive set of olympiad programming tasks. To submit solution you need to be signed in system. You can register or sign in into existing account and submit solutions to problems. The testing system runs in separate judge worker processes. Judge jobs are stored durably in Postgres and each worker process owns one fixed, locally locked isolate box id. System will automatically test your solution in isolated sandboxes provided by isolate and report verdict, max used time and max used memory.
Also, each problem has editorial and solution in C++ language.
Platform administrators can add new problems.

Jobs

In the platform you can also find or publish/edit/delete job. There are 2 types of accounts:

1. Common account - these users can find job and communicate with employers by email or phone.
   Open job that you liked, read the description and if job suits you, communicate with employer by email or phone.
2. Business account - these users or companies can publish, edit or delete jobs, also find and communicate by email or phone with other users.
   Publish job, edit it if it is need, and just wait until some qualified specialist will communicate with you by email or phone number.

Profile

In the profile, you can see user's username and statistics about problems: submissions statistics and last 10 attempts. Email and phone number are shown only on your own profile.
Also you can change your icon or password in 'Edit profile' page.

Internal API (Not Public)

The Django REST endpoints under /api/* are intended for internal use (Next.js server + nginx private connectivity) and are protected by INTERNAL_API_KEY. Requests without the correct X-Internal-API-Key receive 404.

The browser should talk only to the Next.js app. Client-side mutations use Next.js /backend/* route handlers which proxy to Django and attach the internal key.

The realtime SSE service is also internal-only and expects the same X-Internal-API-Key header (Next.js proxies SSE streams to it).

Deployment (Nginx)

Recommended approach:

• Public: Next.js on /
• Public: Django on /admin/, /static/, /media/
• Do not expose Django /api/ publicly (it is protected, but should still be treated as internal-only)
• Keep the realtime SSE service internal-only (Next.js proxies to it)

Set env vars:

• Django: INTERNAL_API_KEY
• Realtime: INTERNAL_API_KEY and REALTIME_REDIS_URL
• Next.js: BACKEND_ORIGIN (internal Django origin), INTERNAL_API_KEY (same value), REALTIME_ORIGIN (realtime service origin)

Technologies

Following technologies and libraries were used to create this project:

• Django
• Django REST Framework
• FastAPI
• Uvicorn
• Next.js
• PostgreSQL
• isolate
• Redis
• Pillow
• ZipFile
• io

Components (CSS and JS)

Following components were used to create this project:

• Bootstrap
• CodeMirror
• marked
• katex
• FontAwesome
• Tailwind CSS

Author

• Rakhmetulla Akram - spike1236

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
See LICENSE file for details.