Software Engineer, Applied AI - Frontier Engineering

Mercor's mission is to organize human intelligence to power the AI economy. We're a leading AI data company, building the layer between human expertise and frontier models. Millions of domain experts on the platform are paid over $4 million per day to train frontier AI models. Mercor's APEX benchmark family measures AI's real-world impact on professional work. Mercor Enterprise brings this same infrastructure to Fortune 500 companies: helping companies capture how their best people actually work, translating that expertise directly back into agents.

Mercor is creating a new category of work where expertise powers AI advancement. Achieving this requires an ambitious, fast-paced and deeply committed team. You’ll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society. Mercor is a profitable Series C company valued at $10 billion. We work in-person five days a week in our San Francisco, NYC, or London offices.

As a Software Engineer on Applied AI, you’ll build, deploy, and operate systems that sit directly between frontier AI research and data delivery.

This is a high-ownership, deeply technical role. You’ll work through ill-defined problems, prototype quickly with researchers and customers, and take systems from early experiments to reliable, scalable production. You’ll own projects end-to-end: spanning requirements gathering, creating data creation pipelines, and improving model-adjacent infrastructure, while partnering closely with frontier AI labs and Mercor’s internal teams to ship high-impact applied AI solutions.

• Partner closely with frontier AI labs to understand their data, post-training, and evaluation needs

• Build and operate scalable data pipelines for post-training workflows and model evaluations

• Design and build scalable systems for synthetic data generation and data quality, and work directly with customers to understand requirements and develop technical solutions

• Prototype new data types, benchmarks, and evaluation frameworks

• Lead technical discussions with customers

• Direct frontier exposure. You’ll work closely with researchers at leading AI labs, building infrastructure that directly accelerates cutting-edge research.

• Coding + customer work. This role blends deep technical execution with customer interaction. Engineers who enjoy both building and communicating tend to thrive.

• Fast-moving, high-ownership environment

• Technically demanding, collaborative work

• “Building the plane while flying it”

• In-person culture (SF, 181 Fremont)

• Aligned with frontier research timelines

• Strong backend engineering fundamentals in a modern language (Python, Go, Rust, etc.)

• Experience with model training and inference

• Strong grounding in statistical analysis and experimental design for measuring model performance and improvements

• Familiarity with evaluation methods for large language models

• Comfort working through ambiguity and shipping iteratively

• Enjoys ownership and customer-facing problem solving

• Thinks entrepreneurially and moves quickly

• Balances speed with engineering rigor

• Communicates clearly with technical and non-technical users

• Direct exposure to frontier AI research

• Real ownership and visible impact

• Technical depth paired with human interaction

• Fast feedback loops and high leverage

• There are very few roles that combine this level of technical rigor, customer proximity, and research exposure.

• Bi-annual performance bonus structure

• Generous equity grant vested over 4 years

• Up to $15k Relocation bonus

• $10K proximity bonus (if you live within 0.5 miles of our office)

• $1.5K monthly stipend for meals

• Free Equinox membership

• $200 monthly laundry reimbursement

• $200 monthly personal wellness reimbursement

• Health, Dental, Vision insurance