Lazy Bird mascot

Lazy Bird catches the bug

but is too lazy to fix it.

Technical interviews often test problems you may not have encountered in production. Lazy Bird bridges that gap. Each system is a realistic, broken application that lets you practice diagnosing and fixing real performance issues before you face them in interviews or on the job.

How It Works

1

Clone

Pick a broken system and run it locally with Docker

2

Debug

Investigate the issue using real tools and metrics

3

Fix

Implement the solution and verify it!

Stuck? Each system includes a DETONADO — a step-by-step guide with the solution if you need help.

Get Started

Pick one of the available broken systems:

Data Integrity

Flash Sales

Try it

Database Performance

Employee Directory

Try it

Asynchronous Patterns

Product Catalog

Try it
Explore All 5 systems