Practice Sandbox

Practice Coding Challenges

Sharpen your skills across frontend, backend, AI, DevOps and more. Pick a track, solve real-world problems, and practice for the role you want — all in the same interview environment recruiters use.

12 challenges

EasyComing soon

Build a Todo App in React

Implement a fully interactive todo list with add, complete, and filter states.

FrontendReactTypeScript
EasyComing soon

Responsive Pricing Page

Craft a pixel-perfect, mobile-first pricing section from a design spec.

Frontend
MediumComing soon

REST API with Node.js

Design and build a CRUD REST API with validation and error handling.

BackendNode.jsTypeScript
HardComing soon

Design a Rate Limiter

Implement a token-bucket rate limiter and reason about its trade-offs.

BackendSystem Design
MediumComing soon

SQL Query Optimization

Diagnose slow queries and optimize schema and indexes for scale.

BackendDatabase
HardComing soon

RAG-powered Chatbot

Wire up retrieval-augmented generation over a document set with an LLM.

AIPython
MediumComing soon

Prompt Intent Classifier

Build a lightweight classifier that routes user prompts to the right tool.

AIPython
MediumComing soon

CI/CD Pipeline from Scratch

Author a pipeline that lints, tests, and deploys a service on every push.

DevOps
EasyComing soon

Dockerize a Microservice

Containerize an app with a lean multi-stage build and healthchecks.

DevOpsBackend
MediumComing soon

Python Data Pipeline

Parse, transform, and aggregate a messy dataset into clean output.

PythonBackend
MediumComing soon

Infinite Scroll Feed

Build a performant infinite-scrolling feed with virtualization.

FrontendReact
HardComing soon

Design a URL Shortener

Model the storage, hashing, and read-heavy scaling of a link shortener.

System DesignBackendDatabase

🚀 We're building out the practice sandbox. Every track above will soon be playable in the full interview environment.