Senior Software Engineer, Infrastructure/Platform

Job Description

Job Description

San Francisco, CA · On-site · Full-time Compensation: $180,000–$220,000 + competitive equity

About the Company

An AI research lab pushing the boundaries of artificial intelligence through novel datasets and experimentation, with the frontier foundation-model labs as its customers — every major foundation-model lab is a client. Backed by top-tier investors, growing fast with strong revenue traction, and building out its founding engineering team. Founded 2025 · 11–50 people · Industry: AI research / data infrastructure

The Role

As a Senior Software Engineer, Infrastructure and Platform, you'll design and build the core infrastructure that powers the company's data generation, evaluation, and agentic systems. You'll own the shared platforms that let engineers and research teams run large-scale human-in-the-loop workflows, evaluation harnesses, and automated data pipelines used to train frontier AI models. This is a highly technical role with broad ownership — you'll architect foundational systems many other engineers depend on and work directly with the founding team to define system architecture and set 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 enable product engineers and researchers to build quickly and reliably on top of core systems
• Design systems with strong observability, monitoring, and fault tolerance to support 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, JavaScript (Node.js / Next.js) · GCP / AWS · message queues / event-driven systems (Kafka, RabbitMQ, Pub/Sub) · high-throughput async data pipelines

Requirements

• 5+ years of experience building production distributed systems or platform infrastructure
• Proficiency in Python and/or JavaScript (Node.js/Next.js) or similar backend technologies
• Experience designing and operating systems in cloud environments (GCP or AWS)
• Experience with message queues and event-driven systems (Kafka, RabbitMQ, Pub/Sub, or equivalent)
• Experience working with high-throughput data pipelines and asynchronous processing systems
• Strong understanding of system scalability, performance, and reliability
• Experience owning systems running in production environments at scale
• Background at a top-tier startup or FAANG-equivalent, this is a strong signal of fit
• Undergraduate degree from the U.S., Canada, or the U.K.

Green Flags

• Experience building internal developer platforms or shared infrastructure
• Experience supporting large-scale data processing pipelines
• Experience with AI infrastructure, LLM evaluation systems, or ML pipelines
• Experience working at high-growth startups or scaling early infrastructure
• Experience designing human-in-the-loop or workflow orchestration systems

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

• Architect and own the core infrastructure many engineers and researchers depend on, with broad ownership from day one
• The platforms you build power the data generation, evaluation, and agentic systems used to train frontier AI models
• Work directly with the founding team to define system architecture and set engineering standards
• Fast-growing company with strong revenue traction; competitive salary + equity (4-year vest), daily lunch & dinner, gym membership, health insurance

Details

LocationSan Francisco, CAWork policyOn- siteCompensation$180,000–$220,000 + equityVisa sponsorshipO-1, OPTEmployment typeFull-time

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