Inference Optimization Engineer

About Hedra Hedra is a research and infrastructure lab advancing post-training and inference for multimodal and physical AI. Our ambition is to bring recursive self-improvement to models that learn from and interact with the real world. We combine reinforcement learning research with GPU compute and optimized inference to help teams post-train, serve and continuously improve models they own. We're backed by Index Ventures, a16z and Abstract Ventures. Our team works fully in person in San Francisco. We're looking for people with startup experience who take ownership of their work and care deeply about the problems our customers need to solve. You'll help build the technology, products and business that turn this research into a lasting company. What You’ll Do Work directly with research scientists and engineers to make new visual models fast and efficient at inference time. Profile model architectures and workloads to understand bottlenecks across compute, memory, communication, and model execution. Develop and implement new approaches to improving inference latency, throughput, memory efficiency, and GPU utilization. Explore algorithmic optimizations including quantization, sparsity, caching, compilation, attention optimizations, and alternative execution strategies. Build or optimize GPU kernels using CUDA, Triton, or similar technologies when existing implementations leave performance on the table. Optimize model execution across single-GPU, multi-GPU, and multi-node environments. Reason about the interaction between model architecture and hardware, and work with researchers when architectural changes can unlock meaningful performance improvements. Investigate communication, memory movement, parallelism, and distributed execution strategies for large visual models. Build rigorous benchmarking, profiling, and performance-regression infrastructure to understand performance and evaluate new optimization ideas. Evaluate new inference runtimes, compilers, frameworks, optimization techniques, and accelerator hardware. Stay close to advances in efficient inference, GPU programming, model architectures, compilers, and ML systems research, and rapidly test promising ideas. Help turn research breakthroughs into models that can be deployed and served efficiently at scale. What We’re Looking For Deep technical ability in efficient ML inference, ML systems, GPU computing, or adjacent research, demonstrated through research, production engineering, open-source contributions, or unusually ambitious independent work. Strong understanding of how modern deep learning models execute on hardware, including the relationship between compute, memory, communication, and performance. Experience profiling ML workloads, identifying bottlenecks, forming hypotheses, and driving measurable performance improvements. Strong programming fundamentals in Python, C++, or another systems-oriented language. Experience with some combination of PyTorch, CUDA, Triton, TensorRT, vLLM, SGLang, or comparable technologies. Ability to reason across abstraction layers rather than treating model architecture, framework, runtime, kernel, and hardware boundaries as fixed. Strong intuition for performance tradeoffs across latency, throughput, memory, numerical precision, model quality, and complexity. Curiosity about how models work internally and a willingness to modify or rethink existing approaches when the performance problem calls for it. Comfort working on ambiguous problems where the bottleneck, and sometimes even the right question, is not known in advance. Ability to communicate technical ideas clearly and collaborate closely with research scientists and engineers. We don’t expect every candidate to have experience across the entire stack. Exceptional depth in one or more relevant areas, combined with the ability and curiosity to reason across the others, matters more to us than checking every box. Nice to Have Experience optimizing large generative, multimodal, vision, or video models. CUDA, Triton, CUTLASS, or other GPU kernel development. Deep knowledge of GPU architecture, memory hierarchy, and hardware-aware optimization. Experience with attention optimization, kernel fusion, memory-efficient execution, or custom operators. Model compilation or graph optimization experience. Quantization, sparsity, caching, speculative execution, or other efficient inference techniques. Experience optimizing diffusion, autoregressive, transformer, or other large generative architectures. Multi-GPU or multi-node model execution, including tensor, pipeline, sequence, or other forms of parallelism. Experience optimizing communication or data movement between accelerators. Experience with profiling tools such as Nsight Systems or Nsight Compute. Contributions to ML systems, inference runtimes, compilers, GPU libraries, or performance-focused open-source projects. Research or publications in efficient ML, ML systems, GPU computing, compilers, or related areas. Benefits: Competitive compensation and equity 401k Healthcare (Silver PPO Medical, Vision, Dental) Lunch and snacks at the office This role is based in San Francisco, and we work together in person five days a week.