Competitive Programming Expert - Freelance AI Trainer en Spain, España

Mindrift connects specialists with project-based AI opportunities for leading tech companies, focused on testing, evaluating, and improving AI systems. Participation is project-based, not permanent employment.

We're building competitive-programming problems and their automatic graders (test cases + checkers) used to train advanced AI coding models. You'll create problems, write both correct and deliberately-wrong solutions, and design the tough test cases that catch subtly-broken code. Your work is what makes the training signal trustworthy.

• Write original algorithmic problems - clear statement, sound constraints, an intended solution;
• Write correct solutions in C++ and Python;
• Write realistic wrong solutions (common mistakes) to test against;
• Build and harden test cases: generators, edge cases, stress and "hacking" tests;
• Write checkers/interactors (testlib) for problems with more than one valid answer;
• Confirm the quality bar: correct solutions pass, wrong ones fail, within time limits.

• Strong competitive programming background, shown by a public profile - a Codeforces rating (see levels below), OR an IOI / ICPC / national-olympiad record;
• Fluent contest C++ (STL, complexity); comfortable writing Python;
• Can explain why a solution is wrong and build an input that breaks it;
• Strong written English (C1+).

Levels (by Codeforces rating, or equivalent olympiad achievement):

• Associate - 1700-2100 (Expert / Candidate Master): easier problems;
• Expert - 2200-2600 (Master / Grandmaster): harder problems
• Senior / Reviewer - 2600+ (Int'l Grandmaster) or IOI/ICPC medalist: hardest problems + quality review.

• IOI / ICPC alumni and top competitive programmers especially encouraged to apply;
• Experience setting or testing problems for real contests (Codeforces rounds, ICPC, national olympiads, online judges);
• Testlib experience (checkers, validators, generators);
• Experience creating data for LLM code benchmarks or similar RL / evaluation datasets.

Please submit your CV in English and indicate your level of English proficiency.

Paid per accepted task. Your rate depends on the qualification tier you reach and how efficiently you complete tasks - up to the equivalent of $90/hr. Because payment is per task, a faster pace raises your effective hourly rate.

For this project, tasks are estimated to require around 10-20 hours per week during active phases, based on project requirements. This is an estimate, not a guaranteed workload, and applies only while the project is active. Tasks must be submitted by the deadline and meet the listed acceptance criteria to be accepted.

To apply, share: your competitive-programming handle(s) + current/peak rating, any problem-setting experience, and IOI/ICPC/olympiad history.

Apply → Pass qualification(s) → Join a project → Complete tasks → Get paid