Senior Software Engineer, AI Data

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 $500K ARR per employee, we sit among the top 5 most revenue-dense teams within the fastest-growing AI companies today. That's not an accident; it's a deliberate choice to stay lean, move fast, and give every person on the team outsized ownership and impact. With thousands of customers including Granola, Fireflies, Figure AI, and CallRail, the company has real scale - processing over 2 million hours of audio daily and handling more than 1 million API calls every day. This is a rare growth-stage opportunity where the business is proven and the trajectory is steep, but the team is still small enough that your fingerprints are on everything. If you've ever felt buried under layers of bureaucracy, starved of real ownership, or frustrated watching your work disappear into a slow-moving org, AssemblyAI is built differently. The company operates as a true meritocracy, with no heavy planning or approval processes and no gatekeeping on the tools or information you need. For anyone who genuinely cares about voice AI, not as a trend to chase, but as a technology to build, this is the place where the most interesting problems at the most interesting scale are being solved by a team small enough that you'll actually know everyone's name. We’re committed to creating a space where our employees can bring their full selves to work and have equal opportunity to succeed. No matter your race, gender identity or expression, sexual orientation, religion, origin, ability, age, veteran status, if joining this mission speaks to you, we encourage you to apply! About the Role We're seeking an exceptional Senior Software Engineer to join our AI Data team. This role is focused on building robust, scalable systems that power our AI data platform. You’ll work on high-impact projects that directly influence our ability to train and evaluate models at scale, with a strong emphasis on software engineering excellence, system reliability, and code quality. As a Senior Engineer, you'll drive technical execution within your team, taking ownership of significant features and components. You should be passionate about writing clean, maintainable code, implementing comprehensive testing strategies, and continuously improving engineering practices. This role requires close collaboration with researchers, platform engineers, and other stakeholders. You'll need to balance technical excellence with pragmatic delivery in a fast-paced startup environment. What You’ll Do Architect Next-Gen AI Data Infrastructure Design scalable, future-proof data platforms optimized for AI research workloads Build efficient self-serve data processing pipelines leveraging GCP's advanced services Implement cost-effective storage and monitoring solutions for ML at scale Create flexible training resource management with intelligent queuing Optimize resource allocation for maximum training efficiency Participate in on-call rotation to ensure system reliability Advance Technical Excellence Lead adoption of cutting-edge ML tools and frameworks, continuously evaluating and integrating best-in-class solutions Streamline existing workflows while introducing new tooling that further reduces complexity Enhance our tooling and documentation to accelerate team velocity and maintain our competitive edge Implement guardrails for cost, quality, and performance Identify and eliminate technical bottlenecks in the data processing and training pipelines What You’ll Need 5+ years of professional ... (truncated, view full listing at source)