If you wanna test a live deploy try this website : https://full-stack-dsa-and-algorithms-engine-1.onrender.com/ (It runs on a free tier so it might be a bit slow , Note: No scheduled session cleanup / memory eviction was implemented. On Render free tier upon inactivity Render restarts fresh on the next request which clears all in-memory session state as a side effect)

Full Stack DSA and Algorithms Engine

A full-stack DSA Engine: a FastAPI backend implements the actual data structures and algorithms, a React frontend renders and animates them. Each visitor gets their own isolated session (via a cookie), so multiple people can use the app at the same time without stepping on each other's data.

Features

• Linked List — append, merge sort, clear
• Stack — push, pop
• Sorting Visualizer — bubble / insertion / selection sort with a full step-by-step trace you can play, pause, and step through frame by frame

Architecture

• main.py — FastAPI app. All state lives server-side, keyed by a per-visitor session id set as an httponly cookie on first request.
• frontend/ — React + Vite. src/api.js centralizes API calls and makes sure the session cookie is always sent (credentials: 'include').

Running locally

Backend

python -m venv venv
source venv/bin/activate  
pip install -r requirements.txt
uvicorn main:app --reload

Runs on http://localhost:8000.

Frontend

cd frontend
npm install
npm run dev

Runs on http://localhost:5173.

By default the frontend talks to http://localhost:8000/api and the backend allows requests from http://localhost:5173. To point elsewhere, set VITE_API_BASE (frontend) and FRONTEND_ORIGINS (backend, comma separated).

API overview

Endpoint	Description
POST /api/add-node, GET /api/get-nodes, POST /api/sort-list, POST /api/remove-list	Linked list
POST /api/add-stack-node, POST /api/pop, GET /api/get-stack-nodes	Stack
POST /api/sort/set-array, GET /api/sort/get-array, POST /api/sort/run	Sorting