Join Hire Hangar and work with fast-growing global companies while building a long-term career. Job Title| Founding Performance Engineer Location | On-Site — San Francisco, CA Time Zone | PST Role Overview: We are seeking a Founding Performance Engineer to help build the technical backbone of a fast-moving AI video infrastructure startup. The company's first product turns prompts and documents into whiteboard-style explainer videos in seconds, with a bigger goal of making video generation as fast, cheap, and programmable as text generation is today. As one of the first engineering hires, you'll own the systems that determine how fast and efficient the product feels — going deep on real bottlenecks rather than surface-level fixes. This role suits someone who is energized by understanding exactly how software behaves under load, and who enjoys turning messy internals into clean, fast, dependable systems. Key Responsibilities: - Diagnose and resolve performance bottlenecks across code, media pipelines, and infrastructure - Build tools for benchmarking, regression tracking, and performance testing - Optimize concurrency, caching, batching, and scheduling across core workflows - Improve GPU and compute resource utilization - Design clean internal interfaces around complex, performance-critical systems - Partner with the product team to keep improvements invisible but impactful to users Required Qualifications: - Strong grasp of systems fundamentals: latency, throughput, memory, CPU/GPU, and I/O - Experience improving performance in real production software - Proficiency in C++ or a similar low-level language, alongside backend development skills - Ability to measure rigorously before optimizing, and explain tradeoffs clearly - Comfortable using AI tools to increase speed, while relying on personal judgment to define and solve problems - Must be willing to work on-site in San Francisco, CA Preferred Qualifications: - Background in robotics, embedded systems, or electronics engineering - Comfortable working deep in the stack, below user-facing features - Demonstrated history of measurable performance wins in production systems Tools & Technology: - C++ or similar low-level languages -Backend/API frameworks and databases - Cloud infrastructure and deployment tooling - AI-assisted development tools We connect top talent with vetted employers, competitive pay, and real growth opportunities.