Open Source Applied Engineer Talent Network

$100–150/hrrate as listed

Mercor is building a bench of active open source contributors to design coding evaluations and test cases across Python, Java, C, JavaScript, and TypeScript. Work is remote and asynchronous, with observed rates of $100–150/hr depending on language depth and contribution history.

Summary, eligibility guidance and screening preparation are prepared by Sidequest from the platform's posting. Check the source listing before applying.

What the work involves

You write and review evaluation tasks that probe how well AI systems handle real engineering work — not toy exercises. In practice that means constructing problems drawn from the kinds of issues you already triage in open source: a failing build under a specific toolchain, a subtle concurrency bug, a refactor that has to preserve public API behavior. Each task ships with test cases that actually discriminate — passing for a correct solution, failing for the plausible-but-wrong one — plus a rubric or reference solution that another engineer can audit.

A second strand of the work is analysis. You run models against real-world use cases in your language, catalogue where they break down (hallucinated APIs, mishandled build systems, plausible code that fails under load), and write that up for the research team in terms specific enough to act on. Clear written communication matters more here than it does in most contract engineering work.

What the platform screens for

Verifiable contribution history. Mercor's screen leans heavily on a public GitHub or equivalent profile with frequent, substantive commits to well-used projects in the last 12 months. Drive-by typo fixes and self-authored repos with no users won't clear the bar.
Depth in at least one language. Expect follow-ups on the internals of your ecosystem — GIL semantics, JVM memory model, undefined behavior in C, the TypeScript type system, whatever matches your claim.
Evaluation judgment. Can you tell a hard task from a merely long one, and write tests that fail for the right reasons?
Architecture and performance reasoning, since many tasks turn on scalability and code quality rather than correctness alone.

Logistics

Fully remote and asynchronous, structured as a talent network rather than a single fixed engagement — you're matched to projects as they come up. Commitments are typically part-time and flexible, often 10–20 hours per week, though some projects request more. Pay observed in the $100–150/hr range; actual offers vary by language, project, and screening outcome, and nothing here is a guarantee. Git, CI/CD fluency, and comfort operating with minimal oversight are assumed throughout.

What they look for

Sustained, high-quality contributions to widely-used open source repositories within the last 12 months
Deep expertise in at least one of Python, Java, C, JavaScript, or TypeScript, including its major libraries and frameworks
Test design — writing discriminating test cases and reproducible failure conditions
Software architecture, performance tuning, and scalable code patterns
Git, CI/CD pipelines, and open-source governance workflows (code review, issue triage, RFCs)
Clear technical writing for asynchronous, distributed collaboration

Before you apply

Would you pass this screen?

Drawn from what this listing actually requires. Answered in your browser — nothing is sent to us, and we do not store your answers.

Do you have at least 5 merged pull requests or equivalent contributions to public open-source repositories in the last 12 months?
Active open-source contributions · required
Do you have production or substantial open-source experience in at least one of these languages: Python, Java, C, JavaScript, or TypeScript?
Language expertise · required
Are you comfortable with Git workflows and have you used at least one CI/CD system (GitHub Actions, GitLab CI, Jenkins, CircleCI, etc.) in a real project?
Git and CI/CD fluency · required
Do you have a GitHub account or equivalent public profile where your open-source work is visible?
GitHub or equivalent public profile · required
Have you worked asynchronously in a distributed team or collaborated on an open-source project where you could not rely on real-time communication?
Distributed team experience · preferred

0 of 5 answered

Included with this listing

Interview prep — 10 questions

Matched to what this platform's screening actually measures. Answer each out loud in 60–90 seconds: claim → concrete example → implication.

What it tests: Whether the candidate has genuinely shaped an active open-source project, not just submitted cosmetic PRs. Can they articulate impact and understand how their work was received by the community?
A strong answer: The candidate names a specific repository and contribution, explains the technical problem it addressed (not just 'improved code'), and describes tangible outcomes—merged PRs, issues resolved, or feedback from maintainers that shows the work mattered.
Where people lose it: Candidates describe minor fixes (typos, formatting), contributions to inactive/small projects, or vague claims like 'helped with performance'—which signals either shallow involvement or inability to judge what counts as meaningful work.