Aviationstack is a scalable REST API for real-time flight tracking, historical flight data, airport info, and global aviation data.
from $49.99/mo
About CodeCrafters
What is CodeCrafters?
CodeCrafters is a platform for experienced developers who want to deepen their understanding of core computer science concepts by rebuilding the tools they use every day. Instead of watching tutorials or solving algorithm puzzles, you build real systems — like a Redis clone, a Git client, an HTTP server, or a SQLite database — from the ground up, in your own programming language and editor.
Who is it for?
CodeCrafters is designed for professional software engineers, SREs, and principal engineers who already know how to code but want to master system internals. It is not for beginners learning to program — the challenges assume solid coding proficiency and focus on architecture, protocols, and low-level details.
How does it work?
Pick a challenge (e.g., Build your own Redis, 97 stages), open your preferred IDE, and git push to get instant test feedback. Real-time results and hints appear in seconds. Challenges range from 7 to 97 stages, covering topics like TCP servers, HTTP protocol, LDAP, peer-to-peer networking, and agent loops. Code examples and anonymous mode are available on paid plans.
Real use cases
Use CodeCrafters to upskill before a system design interview, to gain confidence reading protocol specifications, or simply to satisfy curiosity about how distributed systems, message queues, and databases work under the hood. It is also popular for team learning via a Teams plan with leaderboards and Slack integration.
Key features
- Real systems, not toy projects — Rebuild Redis, Git, SQLite, Kafka, HTTP server, Shell, grep, BitTorrent, Interpreter, and more from scratch.
- Code in your own environment — Use your IDE, extensions, and terminal. No toy editors or restrictions.
- Instant feedback via git push — Run automated tests and receive results and hints in seconds.
- Multiple stages per challenge — Deep, progressive learning (e.g., 97 stages for Redis, 47 for Shell).
- Multi-language support — Complete challenges in your language of choice (Python, Go, Rust, Java, etc.).
- Anonymous mode — Hide your progress publicly (Membership plan).
- Turbo tests for instant feedback — Membership feature for faster iteration.
SaaSpartout Score
6.9
/10
Editorial score from our review methodology — not user ratings.
◆ AI advisor — 30 seconds, no signup
Why are you looking at Testing tools today?
CodeCrafters Pricing
CodeCrafters pricing: from $39/mo.
For comparison: the median starting price in Developer Tools is $19.99/month, measured across 301 tools we track. See the full SaaS Pricing Index →
Free Plan
Limited content access, community features. No credit card required. Best for trialing the platform.
Membership Plan
No limits on content. Includes turbo tests (instant feedback), code examples, anonymous mode, and over $1,000 in perks. Plans available in 3-month, 1-year, and lifetime options. Starting at about $39 per month (annual).
Teams Plan
Everything in Membership, plus unlimited seat re-assigns, team leaderboard, team usage analytics, Slack app. Swappable seats, billed annually. For teams of 5 or more.
Free trial: Limited access without credit card. Paid plans offer a full feature set.
Frequently asked questions
Does CodeCrafters have a free plan?
Yes, CodeCrafters offers a free plan with limited content access and community features. No credit card required.
How much does CodeCrafters cost?
Membership starts at about $39 per month (billed annually) with 3-month, 1-year, and lifetime options. Teams plans are available for 5+ members with annual billing.
What languages can I use on CodeCrafters?
CodeCrafters supports multiple programming languages including Python, Go, Rust, Java, JavaScript, and more — you code in your own IDE and language of choice.
Who is CodeCrafters best for?
It is best for experienced software engineers, SREs, and principal engineers who want to master system internals. It is not suitable for beginner programmers — challenges assume strong coding skills.
What are the top alternatives to CodeCrafters?
Alternatives include Exercism (guided programming practice), Advent of Code (algorithmic puzzles), and O'Reilly (tutorials/books), but CodeCrafters is unique in focusing on rebuilding real systems from scratch like Redis, Git, and SQLite.
How long do CodeCrafters challenges take?
Each challenge has multiple stages — for example, Redis has 97 stages, Shell has 47, Git has 7. Completion time varies from a few days to several weeks depending on the challenge and your pace.
