Senior Software Engineer Infrastructure / Platform

KTS is hiring on behalf of a fast‑growing YC‑backed AI startup building core infrastructure used by frontier AI labs. We are looking for a Senior Software Engineer Infrastructure / Platform This is a high‑ownership engineering role for someone who wants to build the platform layer behind large‑scale data generation, evaluation systems, human‑in‑the‑loop workflows and agentic AI experimentation. You will work directly with the founding team to design and build the shared infrastructure that enables engineers and researchers to run high‑throughput workflows reliably at scale. This is not a standard backend role. The ideal candidate has strong production infrastructure experience, deep systems judgement, and the ability to build reliable platforms in a fast‑moving, early‑stage environment. What you’ll work on You will help architect and build the infrastructure powering data generation platforms, evaluation pipelines and human‑in‑the‑loop systems used in frontier AI development. You’ll create reusable APIs and internal platforms, improve reliability and observability, design high‑throughput async processing systems, and help define engineering standards across deployment, infrastructure, system design and operations. What we’re looking for Strong candidates will bring: 5+ years building production distributed systems, backend platforms or core infrastructure Experience designing and operating cloud systems on AWS or GCP Hands‑on experience with message queues and event‑driven systems such as Kafka, RabbitMQ, Pub/Sub or similar Strong understanding of scalability, reliability, performance, observability and fault tolerance Experience owning production systems used at scale Background from a high‑growth startup, top‑tier engineering company or FAANG‑equivalent environment Comfort working closely with founders, engineers and researchers in a high‑velocity environment Bonus points for experience with AI infrastructure, LLM evaluation systems, ML pipelines, human‑in‑the‑loop workflows, workflow orchestration, large‑scale data processing or internal developer platforms and top‑tier university. Why this role is exciting You’ll be joining an early, high‑calibre team building infrastructure that directly supports the next generation of AI development. This is a chance to own major technical decisions, shape platform architecture from an early stage, and work with world‑class engineers and researchers on systems that need to be fast, scalable and reliable from day one. Employment: Full‑time Hiring process Recruiter screen, technical conversations, system design rounds, work trial, references and offer #J-18808-Ljbffr Key Technology