Crucible

Stop building from scratch.
Start working in real code.

Crucible is a simulation platform where you fix bugs and build features in production-grade codebases.

Practice the work. Build a verified portfolio. Prove you're ready.

Try 5 Tickets Free See Pricing

5 tickets free. No credit card required.

Sample Ticket TKT-9F2A In Progress

Users can still access app after logging out

crucible-starter

Reported by: Mike Torres (Engineering) • Priority: P2

We're getting reports from users that after clicking "Log Out," they can briefly still hit authenticated endpoints with their old session token. I think this is a race condition in the logout flow...

This is what a real Crucible ticket looks like. No tutorials. No hand-holding.

Real engineering work. Simulated environment.

Not tutorials. Not toy projects. The same types of tasks you'd get in your first week on the job.

Debug & Fix

Race conditions, security vulnerabilities, N+1 queries, validation gaps. Trace bugs from vague user reports to root cause.

Build & Ship

New API endpoints, frontend components, validation logic. Implement features from a ticket spec just like a real team.

Verify & Prove

Push your code, our test suite runs automatically. Pass it and it's a verified entry in your portfolio with resume bullets and interview prep.

How It Works

1

Get a Ticket

You're assigned a bug report or feature request, written like it came from a real team.

2

Clone & Code

Clone the repo, investigate the codebase, write your fix or feature. Your own private GitHub repo.

3

Push & Verify

Push your code. Our automated test suite verifies your solution works correctly.

4

Portfolio Entry

Every completed ticket becomes a verified portfolio entry with interview talking points.

The Portfolio Problem

Every bootcamp grad has the same todo apps and weather widgets. Hiring managers can't tell who can actually work in existing code.

Typical Junior Portfolio

  • Projects built from scratch following tutorials
  • No evidence of debugging or investigation
  • No proof they can navigate unfamiliar code

After Crucible

  • Verified fixes and features in a real codebase
  • Portfolio entries with interview talking points
  • Resume-ready portfolio with interview talking points

What You'll Work On

TypeScript, Next.js, Prisma, REST APIs. The stack companies are actually hiring for.

Security

XSS vulnerabilities, missing auth checks, input sanitization

Performance

N+1 queries, missing indexes, memory leaks, slow endpoints

Logic

Race conditions, off-by-one errors, broken state management

Features

New API endpoints, frontend components, validation schemas

Data

ORM queries, schema mismatches, data integrity issues

Integration

API contracts, async flows, error handling, middleware

Build Skills That Actually Transfer

Every ticket you complete is practice for the work you'll do on the job. Debug, build, ship, repeat — on your schedule.

Start Free

5 tickets free. No credit card required.