Staff Software Engineer

About the Role We're a small, early-stage AI/ML startup — backed by Y Combinator — building sophisticated reinforcement learning environments that train AI models to perform complex, expert-level tasks. As a Staff Software Engineer , you'll play a pivotal role in shaping our technical direction, architecting the core systems that power our platform, and raising the technical bar across the engineering organization. This is a high-impact, hands-on leadership role at a fast-moving team where your decisions will have outsized influence. This is a hybrid role based in Los Angeles, CA . Please note that visa sponsorship is not available for this position. What You'll Do Lead the architecture and design of scalable, high-impact systems and services. Implement and ship production-quality code that balances performance, observability, and maintainability. Drive system reliability and performance improvements through proactive monitoring, incident response, and remediation. Mentor and coach engineers across the organization to improve engineering practices and accelerate technical growth. Collaborate with product, design, and cross-functional teams to translate product needs into robust technical solutions. Establish and promote best practices for testing, code review, and deployment workflows. Influence the technical roadmap and make thoughtful trade-offs aligned with business and operational goals. What We're Looking For Must-haves: 8+ years of professional software engineering experience, with several years in senior or lead technical roles. Proven track record leading architecture decisions across multiple engineering teams. Experience building and delivering large-scale distributed systems at production scale. Hands-on experience designing and delivering production-grade backend services in cloud environments, including microservices, Docker, and Kubernetes. Experience deploying services to cloud platforms (AWS, GCP, or Azure) and operating containerized applications with CI/CD pipelines. Proficiency in at least one backend programming language — Python, Go, Java, or Node.js — with a strong record of production-grade code. Strong computer science fundamentals: algorithms, data structures, and system design. Demonstrated ability to mentor engineers, lead technical discussions, and influence cross-functional stakeholders. Nice to have: Experience with relational and NoSQL databases and data modeling. Familiarity with observability and monitoring tools such as Prometheus, Grafana, or OpenTelemetry. Experience with event-driven architectures and streaming systems (e.g., Kafka, RabbitMQ). Location This is a hybrid position based in Los Angeles, CA . Candidates should be located in or willing to relocate to the Los Angeles area. Visa sponsorship is not available .