How does this differ from codecrafters.io?
its free
And entirely AI generated
I kept noticing that most "learn to code" content is tutorials you copy-paste, so I never had to actually understand why anything worked. I built this to flip that: each lesson gives you a real spec (e.g. implement the Redis SET/GET protocol) and you write the code yourself, then it actually runs against tests. Right now there are 80+ of these "build X from scratch" courses — Redis, a database, Git, a compiler, a container runtime, a raft KV store, etc. — across Python, Go, Rust, C, C++, and others. Would love feedback, especially on where the early lessons feel too hand-holdy or too sparse.
I've helped people get into programming face to face and also in a site I liked called exercism which also had a multi language track unit test passing style which I really value and it was purely command line, and I can't stress enough how important the command line is for me for people who want to dabble. Nowadays it's easier to get people into the command line because of Claude/codex.
I only have browsed your site from a phone and looks interesting but I wanted to ask if you had particular insights around getting people to approach learning, design through tests, breaking down problems, without having someone to guide them. Have you had a chance to observe people using your tool and adjust or it's been mostly dog fooding something you would've loved to have.
Is this going to remain free? I´d love an open source project like this where I could run the tests in my own machine.
First impression - looks great. Congrats.
I have couple of questions:
* I didn't see any AI mention, was it entirely built by humans without AI ?
* Were will the tests run ? Your servers or the user machines ? If on your servers, how do you plan to cover the costs if you don't charge for the service ?
* Will you accept contrbutions to the teaching material? How can other people contribute to the teaching material ? What is the AI policy for contributors ?
1. We have temporarily removed it due to abuse (people are sending their own project code through it). 2. Tests are run on our dedicated server. I had some spare servers that we bought for our other platform echoed. gg 3. Will you accept contributions to the teaching material? ofc we would. I am also thinking of open-sourcing the project 4. What is the AI policy for contributors? You can use AI(we also used it), but the quality of the course, should match the rest of the courses