Software Engineer (Mid-level)

About Mercor

Mercor is training models that predict how well someone will perform on a job better than a human can. We use our platform to source, vet, and onboard expert contractors who help train AI models in a wide variety of domains. Our technology is so effective it’s used by all of the top 5 AI labs. We scaled from $1–$500M in revenue run rate in the last 17 months, making us the fastest growing company in the world. Our growth is accelerating : 11% week-over-week in July, 18% in August, and 19% in September. The team is small, profitable, and growing as fast as we can hire exceptional people.

About the Role

As a Software Engineer at Mercor, you’ll join a small, product-driven engineering team building modern backend systems that power critical workflows for some of the most advanced AI companies in the world. You’ll own projects end-to-end, designing, building, and shipping production systems that directly impact customers. From day one you’ll write production-grade code, reason about systems holistically, and make decisions that tie directly to business outcomes. You’ll work closely with product and design, moving fast while upholding a high bar for code quality, scalability, and simplicity.

At the end of the process, you’ll be team-matched to where you can have the most impact, on one of the following :

Talent platform side – building next-generation tools that automate recruiting end-to-end, intelligently match candidates to roles, and power global hiring with seamless contracts and payments.

Applied AI / human data side – partnering with top AI researchers from the AI labs like OpenAI, Anthropic, and Google to create post training datasets to improve foundational model capabilities.

What You’ll Do

Design and build scalable backend APIs, services, and infrastructure.

Collaborate across the stack with product and design to ship features quickly.

Write clean, maintainable code and contribute to documentation.

Participate in code reviews, technical design discussions, and retros.

Solve real-world customer problems under real-world constraints.

Contribute to core systems that power training, evaluation, and scaling for leading AI labs.

What We’re Looking For

Strong coding fundamentals in at least one modern language (Python, Go, Rust, etc.).

Understanding of data structures, algorithms, and distributed systems.

Familiarity with APIs, SQL / NoSQL databases, and cloud platforms (AWS / GCP).

Bias toward ownership, curiosity, and asking the right questions.

Ability to break down ambiguity and ship simple solutions to complex problems.

Why Mercor

Impact : Your work powers how the world’s leading AI labs train and test their models.

Learning : Get early insights into frontier model capabilities months before the market.

Growth : Work on both infrastructure and research-adjacent projects with fast paths to ownership.

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