Senior Software Engineer, Inference - AssemblyAI

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.

We are one of the most capital-efficient AI companies on the planet — with under 100 people generating roughly $500K ARR per employee. We operate as a true meritocracy, offering outsized ownership and impact without the bureaucracy of slow-moving organizations.

About the Role

We're hiring a Software Engineer to help turn cutting-edge AI research into products our customers rely on every day. You'll sit on a fast-paced engineering team between our research org and our Applied teams, taking new model capabilities from proof of concept to robust, well-documented APIs serving production traffic at scale.

What You’ll Do

• Design and ship customer-facing APIs that expose new model capabilities, owning them from prototype through launch and ongoing iteration.
• Scale inference infrastructure to support our 1M+ API users.
• Partner with researchers to productionize new techniques, turning notebooks or POCs into systems with the latency, reliability, and ergonomics customers expect.
• Work with customers and Applied teams to understand how users are building with our products, feeding insights back into product design and research direction.
• Contribute across the stack as needed: backend services, inference infrastructure, SDKs, and internal tooling.

What You’ll Need

• Strong backend engineering experience, including building and supporting machine learning infrastructure and/or customer-facing APIs in production.
• Comfort operating with ambiguity. You are energized rather than frustrated by the realities of aligning research and product timelines.
• Genuine curiosity about AI/ML. You don't need to be a researcher, but you should want to understand what models are doing well enough to make good engineering decisions.
• Strong collaboration skills. You'll work daily with researchers, applied engineers, and customers who have diverse contexts and priorities.