AssemblyAI: Senior Research Engineer

About the role

Headquarters: Remote Why AssemblyAI AssemblyAI builds the best-in-class Voice AI models powering the next generation of voice applications. Our models serve 600M+ inference calls monthly, process 1M+ hours of audio daily, and power 2 billion+ end-user experiences. The Voice AI space is at an inflection point; we’re looking for folks truly excited to join a small team and help define the future of the industry. We are one of the most capital-efficient AI companies on the planet - with under 100 people generating roughly $600K ARR per employee, we sit among the top 5 most revenue-dense teams wit

Requirements

• Expert-level proficiency with JAX and TPUs , including the surrounding ecosystem (Flax, Optax, the XLA compilation pipeline).
• Measurement discipline. You define what success looks like before you start, you stay skeptical of your own results until they hold up, and you treat an unexplained improvement as a problem rather tha
• Appetite for the whole pipeline. Your core strength might be JAX and TPU performance, but when a customer issue traces back to a data problem or an evaluation blind spot, you want to go find it yourse
• Strong experience optimizing inference systems for production, ideally with LLMs or speech models.
• Deep understanding of distributed training at scale, modern deep learning systems, and ML infrastructure best practices.
• Familiarity with modern inference optimization techniques: continuous batching, KV-cache management, sharding strategies, quantization.
• Enthusiasm for refactoring and improving existing systems — you thrive on making products and code faster and better.
• Strong Python skills; C++ or Rust experience for kernel-level work is a plus.