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Practice Writing
Complex Software.

Recreate Redis, Git, Docker — with your own hands. Gain expert-level confidence by taking action and diving deep, learning from the world's best.
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Learn to do it right — from the best.

Build complex projects and discover best practices through
expert-reviewed recommended approaches.
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JJ Kasper
Maintainer of Next.js

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Reviewer for JavaScript
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Marcos Lilljedahl
Docker contributor & ex
Head of DevOps @ Vercel

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Reviewer for Golang
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Juan Campa
Chromium Hacker @ Mighty &
ex Architect @ Zynga

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Reviewer for Rust
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Stan Lo
Ruby Infra @ Shopify &
Rails contributor
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Reviewer for Ruby
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Paul Kuruvilla

CTO, CodeCrafters


Solutions Author
Trusted by engineers at top companies with learning budgets
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Hear it from our members

Engineers at top teams love The CodeCrafters Way™
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)
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Charles Guo
Scala Team at Stripe
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I'm learning about how Redis works under the hood, system calls, socket programming in Python — something I've never done before
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Akshata Mohan
Senior Data Scientist at Cloudflare
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I've started the Docker challenge, enjoying it a lot so far. Just the right level of guidance, helpful and still gives you a lot of freedom to explore and learn for yourself.
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Maya Farber Brodsky
Recurse Center Participant
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My favorite way to master a language.
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Pranjal Paliwal
$35k winner of HackAtom
Found out from a colleague. It has you build your own version of things like Git and Docker from scratch. A cool way to build a stronger mental model of how those tools work.
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Beyang Liu
CTO at SourceGraph
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The Docker challenge helped me dive into its internals, through *actual* practice. Super fun.
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Kang Ming Tay
Software Engineer at Supabase
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I was really impressed that they support Haskell, and will probably usethis to learn Rust! The git-based workflow is :chefkiss:
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Jonathan Lorimer
Lead SWE at Mercury Bank
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The instant feedback right there in the git push is really cool. Didn't even know that was possible!
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Patrick Burris
Senior Software Developer at CenturyLink
Projects that go
way beyond the basics
The most respected engineers got there by improving the depth of their understanding — and you can too.

Recreate timeless software and experience advanced system design concepts, while developing an appreciation for tools you use everyday.

Most languages supported.
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)
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Charles Guo
Scala Team at Stripe
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Inspiration directly from
how the experts do it
Reading good code is as important as writing code.

First build the project your way. Then compare with the CodeCrafters approach. And finally, navigate the official source code to see how it's done.

A great headstart into becoming an OSS contributor.
These guys ruined my weekend
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Djordje Lukic (@rumpl)
Full-time Docker contributor
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Adventures that you'll
love bragging about
Our members have showcased their CodeCrafters experience during Learning Fridays, at book clubs, on their blogs, CVs... even email footers.

Which friends will you show your projects?
I spent a full day on your Docker building course and ended up building the whole thing myself. As a SRE (and mostly a user of docker), digging into the internals blew me away.
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Raghav Dua
SRE at Coinbase
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The world's best got better by doing.

Hear from Pete Koomen, co-founder & CTO of Optimizely, on how he learns.