Free GitHub repositories created by the developer community to help people prepare for coding interviews, system design, algorithms, and even behavioral questions.
Here’s a curated list of the best types of GitHub repositories (all free!) for interview and coding support:
- Algorithm and Data Structure Practice
Repo: The Algorithms
Link: https://github.com/TheAlgorithms
Description: Implementations of algorithms in many languages (Python, Java, C++, etc.)
Repo: Leetcode Patterns
Link: https://github.com/SeanPrashad/leetcode-patterns
Description: Covers common patterns behind Leetcode questions - helps recognize question types fast
Repo: 500 Data Structures and Algorithms Problems and Solutions
Link: https://github.com/mission-peace/interview
Description: A curated list of common problems and their solutions with explanations
Repo: Coding Interview University
Link: https://github.com/jwasham/coding-interview-university
Description: A complete self-taught CS curriculum to pass coding interviews at big tech companies
- System Design
Repo: System Design Primer
Link: https://github.com/donnemartin/system-design-primer
Description: #1 resource on GitHub for learning system design - clear, practical, and beginner-friendly
Repo: Awesome System Design
Link: https://github.com/madd86/awesome-system-design
Description: Curated list of system design resources, guides, and video lectures
- Frontend-Specific
Repo: Frontend Interview Handbook
Link: https://github.com/yangshun/front-end-interview-handbook
Description: Covers HTML, CSS, JavaScript, React, and behavioral questions
Repo: 30 Seconds of Code
Link: https://github.com/30-seconds/30-seconds-of-code
Description: Short and useful JavaScript code snippets for frontend developers
- Backend / Fullstack
Repo: Backend Interview Questions
Link: https://github.com/arialdomartini/Back-End-Developer-Interview-Questions
Description: A collection of backend-focused interview questions covering databases, APIs, and more
Repo: Awesome Interviews
Link: https://github.com/DopplerHQ/awesome-interview-questions
Description: Categorized interview questions by language and stack (Node.js, Python, Java, etc.)
- Behavioral & General Interview Prep
Repo: Tech Interview Handbook
Link: https://github.com/yangshun/tech-interview-handbook
Description: Includes coding, system design, and behavioral prep in one comprehensive guide
Repo: Awesome Interview Questions
Link: https://github.com/MaximAbramchuck/awesome-interview-questions
Description: Huge list of behavioral and technical questions by topic and language
- Mock Interviews & Project Practice
Repo: Project-Based Learning
Link: https://github.com/practical-tutorials/project-based-learning
Description: Learn by building real-world projects - great for portfolios and interview prep
Repo: Build Your Own X
Link: https://github.com/codecrafters-io/build-your-own-x
Description: Learn core concepts by building your own database, Git, Docker, etc.
:hammer_and_spanner: How to use them effectively
Star and follow the ones that match your role (frontend, backend, fullstack, etc.)
Use the issues/discussions tab to connect with others
Practice daily - many of these have challenge modes or daily coding lists
Follow GitHub users who created these repos - they often share updates and tips