I built a guided Build your own DNS Server challenge

In plain words

This is a self-paced coding challenge that guides developers through building a DNS forwarding server. Available in Rust, Go, and Python, it is designed for intermediate developers and covers DNS protocol fundamentals, packet creation, and query handling. Participants use their preferred tools to complete progressive stages that build upon each other, ultimately resulting in a working DNS server that can create, read, and respond to DNS packets.

written from the facts on this page · September 2026

From the sources

Advanced programming challenges for experienced engineers. Rebuild real production tools like Redis, Git, and SQLite from scratch in your IDE.

You're welcome to study the full challenge structure and stage instructions for free. A membership is needed for submitting code and viewing solutions. Want to try a free challenge? Try Build your own Shell — it's free this month. DNS is a protocol used to resolve domain names to IP addresses. In this challenge, you'll build a DNS server that's capable of responding to basic DNS queries. Along the way you'll learn about the DNS protocol, DNS packet format, DNS record types, UDP servers andfrom app.codecrafters.io

In the maker’s words, at launch

Hey everyone. It's Sherub here, author of the Build your own DNS Server challenge on CodeCrafters. Currently it’s available in Rust, Go, and Python and is free while in beta. https://codecrafters.io/dns-server I've kept the challenge accessible but still challenging for an intermediate developer. This…

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  My goal was to create a DNS server as simple as the LDAP server I've been contributing to (glauth) and here it is: https://github.com/fusion/kittendns A few things to know about it: - It is easy to configure using a Toml file - I am using it to bail my coredns/etcd instances when under attack - (yes, it also works as a service location server) - It comes with a simple, plain English, rule engine that doesn't do much at this point - It can be used with LetsEncrypt. I use it to retrieve certificates for my home servers. - RFC: all the nice ones :) Anyway, feedback is…

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