CodeCrafters

Could you build Claude Code yourself? We’re betting you can. Introducing our newest challenge: Build Your Own Claude Code app.codecrafters.io/courses/claude… You’ve been treating AI agents like a black box. It’s time to crack the box open. Build a working coding agent step-by-step and discover what’s generally under the hood.

Introducing our new website. Build something you didn't think you could. codecrafters.io

Is your coding agent really smart or did it just memorize the test answers? Today we're launching CCBench, a benchmark for evaluating coding agents on small-scale codebases (<10k LoC) that aren't part of LLM training data. It's designed to answer a simple question: How well do agents perform on tasks that aren't part of public training data? ccbench.org Does your favourite agent top the rankings?

This challenge is still in beta. So it's free to try! It's live in 5 languages currently. Support for more languages coming soon.

Could you build Claude Code yourself? We’re betting you can. Introducing our newest challenge: Build Your Own Claude Code app.codecrafters.io/courses/claude… You’ve been treating AI agents like a black box. It’s time to crack the box open. Build a working coding agent step-by-step and discover what’s generally under the hood.

Today we're announcing to give $4,000/yr/engineer to the open source projects we depend on. codecrafters.io/blog/oss-pledge

@rauchg Here’s a master list of ideas github.com/codecrafters-i…

IIT BHU, welcome to the party. We're making CodeCrafters free for all @IITBHU_Varanasi students, staff and alumni.

You're invited to the underground coding club, UC Berkeley. CodeCrafters is now free for all @UCBerkeley students, alum, and staff. codecrafters.io/berkeley

We finally got into IIT. Today we're announcing our partnership with @iitroorkee to make CodeCrafters free for its students, staff and alumni. codecrafters.io/iitr Silicon Valley's favourite challenges. Now at IIT Roorkee.

Today we're making CodeCrafters free for students, staff, and alumni of @NUSingapore. Silicon Valley's favorite coding challenges. Now making its way through Singapore. codecrafters.io/nus

This repository is a compilation of well-written, step-by-step guides for re-creating our favorite technologies from scratch.

Codecrafters wants to challenge seasoned developers with hard-to-build projects tcrn.ch/49ekcXn

Tune in tomorrow for a Q&A with Joe & Stepan, the founders of @instant_db Instant is a modern Firebase that makes you productive by giving your front end an easy, real-time database. It is backed by Paul Graham, Greg Brockman, Amjad Masad and many more. Set a reminder here to speak with Joe & Stepan: x.com/i/spaces/1OdJr…

Join us in our first ever X Spaces session. We're hosting @JoeAverbukh & @stopachka , the founders of @instant_db. Set a reminder here:  x.com/i/spaces/1OdJr…

Starting this week. Stay tuned.

Today we're sharing news about our $1.8M seed fundraise. codecrafters.io/blog/seed

Today, we're joining @getsentry, @convex and others, in going Fair Source. codecrafters.io/blog/fair-sour…

For 10 lucky winners, we're giving away a free copy of the physical book. amazon.com/dp/0990582930 RT the main tweet and start the challenge to become eligible.

Ultimately, you’ll discover how programming languages work and how code is executed, at a fundamental level. Get started here: app.codecrafters.io/courses/interp… The challenge is completely free while in beta.

Today, we’re announcing our latest challenge: Build your own Interpreter. app.codecrafters.io/courses/interp…