Senior Software Engineer, Infrastructure/Platform

Job Description

Job Description

San Francisco, CA · On-site · Full-time
Compensation: $250,000–$350,000 + competitive equity

About the Company

A well-funded AI research lab (Series A) that builds the data-generation, evaluation, and agentic infrastructure used to train frontier AI models, with leading foundation-model labs among its customers. Backed by top-tier venture investors and prominent AI-industry angels, with a founding team drawn from leading quant firms, big tech, and top AI research labs.
Founded 2025 · 11–50 people · Industry: AI research / data infrastructure

The Role

Design and build the core infrastructure powering the company's data generation, evaluation, and agentic systems — the shared platforms that let engineers and researchers run large-scale human-in-the-loop workflows, evaluation harnesses, and automated data pipelines. A highly technical role with broad ownership, working directly with the founding team to define system architecture and engineering standards.

What you'll be doing

• Architect and develop the shared infrastructure powering data generation platforms, human-in-the-loop systems, and evaluation pipelines
• Build systems capable of processing large-scale datasets and high-throughput workloads with strong reliability guarantees
• Create reusable infrastructure and APIs that let product engineers and researchers build quickly and reliably on top of core systems
• Design systems with strong observability, monitoring, and fault tolerance for production workloads at scale
• Help define long-term system architecture across data pipelines, compute infrastructure, task orchestration, and storage systems
• Work closely with engineers and researchers to support new AI experimentation workflows and platform capabilities
• Define standards for system design, deployment, reliability, and infrastructure operations

Tech stack: Python and/or JavaScript (Node.js/Next.js); GCP or AWS; message queues / event-driven systems (Kafka, RabbitMQ, Pub/Sub)

Requirements

• 5+ years building and owning production distributed systems or platform infrastructure
• Strong backend proficiency in Python and/or JavaScript (Node.js/Next.js)
• Cloud infrastructure experience in GCP or AWS
• Message queues and event-driven systems (Kafka, RabbitMQ, Pub/Sub)
• High-throughput data pipelines and asynchronous processing
• System scalability, performance, and reliability ownership
• Shared infrastructure, APIs, and internal platform development
• Observability, monitoring, and fault tolerance design
• Long-term architecture ownership across data pipelines, compute, and storage
• Cross-functional collaboration with engineering and research teams
• Undergraduate degree from the U.S., Canada, or the U.K

Green Flags

• Background at FAANG, Jane Street, Citadel, Stripe, Ramp, or top-tier YC company
• Has architected and owned production infrastructure end-to-end at scale
• Experience building internal developer platforms or shared infrastructure at senior level
• Experience with AI infrastructure, LLM evaluation systems, or ML pipelines
• Has scaled early infrastructure at a high-growth startup
• Experience designing human-in-the-loop or workflow orchestration systems
• Defined architecture decisions and set engineering standards, not just executed them

Red Flags

• Only mid-level or IC contributor experience with no architectural ownership
• Background exclusively at large legacy enterprises or slow-moving companies
• Has never owned a production system end-to-end
• No cloud infrastructure depth in GCP or AWS
• No experience with high-throughput or distributed systems
• Under 5 years of experience

Why Join

• The infrastructure you build directly powers data generation and evaluation for leading foundation-model labs
• Broad, foundational ownership: architect the core systems the whole company depends on, working directly with the founding team
• Opportunity to shape the engineering organization and lead major technical initiatives as the company scales
• Meaningful equity alongside world-class engineers and researchers

Details

• Location: San Francisco, CA
• Work policy: On-site
• Compensation: $250,000–$350,000 + equity
• Visa sponsorship: None available
• Employment type: Full-time