We're building a training ground for engineers who refuse shallow learning.

Plenty of resources out there that teach you how to code.But nothing to help you become exceptionalonce you're past the basics. Until now.

These guys ruined my weekend

Djordje Lukic (@rumpl)

Full-time Docker contributor

There are few sites I like as much that have a step by step guide. The real-time feedback is so good, it's creepy!

Ananthalakshmi Sankar

Automation Engineer at Apple

I spent a full day on your course and ended up building the whole thing myself. As a SRE (and mostly a user of SQLite), digging into the internals blew me away.

Raghav Dua

SRE at Coinbase

The Redis challenge was a great way to procrastinate sleeping for a week! A good change of pace from my regular work, and allowed me to explore some cool tech. I'll be back for more.

Rahul Tarak

Pioneer.app & ODX1 Fellow

The Redis challenge was extremely fun. I ended up having to read Redis protocol specification doc pretty carefully in its entirety! The result felt like lightly-guided independent study, if that makes sense. (Which, again, was lots of fun)

Charles Guo

Scala Team at Stripe

I'm learning about how Redis works under the hood, system calls, socket programming in Python; something I've never done before

Akshata Mohan

Senior Data Scientist at Cloudflare

My favorite way to master a language.

Pranjal Paliwal

Winner of HackAtom

I’ve started the SQLite challenge, enjoying it a lot so far. Just the right level of guidance, helpful yet gives you a lot of freedom to explore and learn for yourself.

Cindy Wu

Participant at Recurse Center

In a perfect world, job interviews ask for assignments like CodeCrafters instead of Leetcode. The best way to refresh your programming language skills and learn something new about Redis, Git, SQLite internals.

Vladislav Ten

SWE at Microsoft

The challenge helped me dive into its internals, through *actual* practice. Super fun.

Kang Ming Tay

Software Engineer at Supabase

I was really impressed that they support Haskell, and will probably usethis to learn Rust! The git-based workflow is :chefkiss:

Jonathan Lorimer

Lead SWE at Mercury Bank

Found out from a colleague. It has you build your own version of things like Git and SQLite from scratch. A cool way to build a stronger mental model of how those tools work.

Beyang Liu

CTO at SourceGraph

#1 repo in the world

444,000+ stars

S2022

Backed by YC

Grant Awardee

Rust Foundation

Our Beliefs

Learning without struggle is entertainment • Convenience creates dependence • Depth creates confidence • The difference between a good developer and a great developer is their appetite for difficulty • Mastery isn't gifted; it's earned.

Our Team

We're a small group of engineers, designers, and writers. We care about two things: doing great work, and helping each other get better.

🇯🇵

Andy Li

Developer Experience

Tokyo, Japan

🇮🇩

Arief Hany

Design

Deli Serdang, Indonesia

🇪🇪

Emily Merin

Partnerships

Tallinn, Estonia

🇳🇬

Oluwabusayo Jacobs

Technical Writing

Lagos, Nigeria

🇺🇸

Paul Kuruvilla

CTO

Cupertino, CA

🇺🇸

Sarup Banskota

CEO

San Francisco, CA

🇳🇵

Udeshya Dhungana

Engineer

Lalitpur, Nepal

🇮🇳

Vedant Nene

Marketing

Mumbai, India

🇵🇭

Vencyr Laurence

Ops

Dumaguete, Philippines

Backed by the best technical investors

Our investors don't sit still. They're constantly building, shipping and shaping the tools the world runs on. Below are some highlights of what they've created.

Mike Krieger

Instagram co-founder

Arash Ferdowsi

Co-founder/CTO @ Dropbox

Jitendra Vaidya

Co-founder @ PlanetScale

Paul Copplestone

CEO @ Supabase

Kevin Van Gundy

COO @ Vercel

Evil Rabbit

Founding Designer @ Vercel

JJ Kasper

Maintainer @ Next.js

Leigh Marie Braswell

Partner @ Kleiner Perkins

Damian Schenkelman

VP R&D @ Auth0

Darby Wong

CEO @ Clerky

Brian Douglas

Head of DevRel @ GitHub

Federico Molina

Head of growth @ Auth0

Marcos Lilljedahl

Head of Infra Ops @ Vercel

Kashif Razzaqui

CTO @ Shuttl

Alana Anderson

Managing Partner @ basecase

Cindy Bi

General Partner @ CapitalX

Albert Lie

1st engineer @ Xendit

Nicolas Hourcard

Co-founder @ QuestDB

Zawad Chowdhury

Co-founder @ Intuned

Ashutosh Joshi

Technical Advisor @ Stanford

Gautam Shewakramani

Head of International @ Quora

Bryan Liu

Head of Talent @ Convex

Ankit Jain

Partner @ Xoogler.co

Ali Moiz

Co-founder @ Stonks.com

Amit Singh

Co-founder @ Shuttl

Deepanshu Malviya

Co-founder @ Shuttl

Ethan Fast

Co-founder @ Vcreate

Matthew Sweeney

Head of CS @ Vercel

Mohammad Gufran

Senior SRE @ Nebius AI

Ray Jang

CEO @ Atria

Varun Shoor

Founder/CEO @ Kayako

Chris Field

Co-founder @ Clerky

Juan Campa

Founder @ Membrane.io

Puspesh

Founder @ Durianpay

Cam Urban

Founder @ Roxy Device

Vijay Sharma

Founder @ Belong.co