Kattis!

A fun social platform for hackers to solve interesting puzzles, build quick hacks, code game bots and collaborate to solve real-world challenges.

Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems.

Duel with friends and foes in head-to-head programming battles!

Coderbyte is a place built for anyone to practice and perfect their programming skills. Challenges are added almost every day so you can work on applying your algorithmic thought process on any problem you want at anytime. Coderbyte is built on improving your ability to work on common logic, mathematical, and algorithmic problems you might one day encounter.

CheckiO is expanding the world’s code literacy through gameplay.

Devskiller is an online testing platform that helps companies verify programming skills. It’s designed to directly address the key problems of hiring the IT talent: • Programming skills quality assessmentDevskiller helps to verify tech skills of programming languages, frameworks and libraries, imitating a real programming environment.• Customized online testingAssessing candidates at the first screening step results in a smaller, better-qualified and suited IT candidate pipeline before the time-consuming process of interviewing.• HR user-friendly toolDevskiller is easy to use for staff with no technical background, decreasing high costs of engaging the tech team.• EducationDevskiller helps also to evaluate the progress of education of programmers.In short, our customers use the platform to reduce the number of unnecessary interviews by 60-70% and to decrease the time-to-hire by 30-50%. »

Achieve code mastery through challenge.Improve your skills by training with others on real code challenges

We provide a way to track progress of many different tools developers use and turn it into an achievements and leaderboard based game. It makes work at a software company similar to playing multiplayer game. Our test group showed that developers (especially those who consider themselves gamers) gain extra productivity and it keeps them motivated and focused on their tasks.

CodeEval is platform for hosting coding challenges which has over 20,000+ competitive developers.

VIM Adventures is an online game based on VIM's keyboard shortcuts (commands, motions and operators). It's the "Zelda meets text editing" game. It's a puzzle game for practicing and memorizing VIM commands (good old VI is also covered, of course). It's an easy way to learn VIM without a steep learning curve.You play a blinking cursor appearing one day in a semi text based world of Textland inhabited by little people but ruled by bugs. You soon discover that your arrival was foretold by an old prophecy and that you're expected to restore order to the world (in case you didn't make it to level 2 yet...). »

Topcoder gathers the world’s experts in design, development and data science to work on interesting and challenging problems. Members are provided with opportunities to demonstrate their expertise, improve their skills, and win cash, while helping real world organizations solve real world problems.

The programmer testing solution that matches your job descriptions and helps you hire great developers faster.

Assess your candidates technical skills with automated online coding interviews. Save Time, Reduce Recruitment Costs and Hire Better Developers

Businesses are run by people. It is the quality of the people that work at any given workplace that determines the success/failure of that particular company. So, how do you ensure that you have the best people working with you at all times? By taking a page out of the book that is Interact, and ditching the traditional interviewing process.

Create your interview or use our templates for FREE. Interview as many candidates as you want for FREE. See candidates' answers and scores for FREE.