Senior Software Engineer, Go - LLM Team

About AssemblyAI

At AssemblyAI, we’re building at the forefront of Speech AI, creating powerful models for speech-to-text and speech understanding available through a straightforward API. With more than 200,000 developers building on our API and over 5,000 paying customers, AssemblyAI is helping unlock and support the next generation of powerful, meaningful products built with AI. 

Progress in AI is moving at an unprecedented pace– and our team is made up of experts in AI research that are focused on making sure that our customers are able to stay on the cutting edge, with production-ready AI models that are constantly updating and improving as our team continues to improve accuracy, latency, and what’s possible with Speech AI. Our models consistently rank highest in industry benchmarks for accuracy, outperforming models from Google and Amazon, and up to 30% fewer hallucinations than OpenAI’s Whisper. Our models power more than 2 billion end-user experiences each day, helping companies better understand customer feedback, run more productive meetings with automated meeting notes, and helping improve childhood literacy via ed tech tools. 

We’ve raised funding by leading investors including Accel, Insight Partners, Y Combinator’s AI Fund, Patrick and John Collision, Nat Friedman, and Daniel Gross. We’re a remote team looking to build one of the next great AI companies, and are looking for driven, talented people to help us get there!

About the Role

We're seeking an exceptional Senior Software Engineer to join our LLM team. This role is focused on building and maintaining our LLM gateway service—a unified API platform that connects customers to multiple LLM providers. You'll work on high-impact projects that directly solve customer problems, improve their AI and agentic workflows, and ensure reliable access to the best models for their use cases.

This is a deeply customer-focused role. You'll work closely with our customer success team to understand customer challenges, help optimize their prompt strategies, build features that address their pain points, and ensure our service reliably delivers value. We're looking for someone who combines software engineering excellence with genuine curiosity about how customers use AI and a drive to make their lives better.

As a Senior Engineer, you'll drive technical execution within the team, taking ownership of significant features and integrations while mentoring more junior engineers. You should be passionate about writing clean, maintainable code, implementing comprehensive testing strategies, and building highly reliable systems in service of solving real customer problems.

This role requires close collaboration with customer success, product managers, external API providers, and other engineering stakeholders. You'll need to balance technical excellence with pragmatic delivery in a fast-paced startup environment where uptime, reliability, and customer success are critical.

What You'll Do

Solve Customer Problems

• Partner closely with the customer success team to understand customer use cases, challenges, and integration needs
• Translate customer pain points surfaced by the CS team into technical solutions and product improvements
• Build features and tooling that directly address customer needs and improve their workflows
• Provide technical guidance and expertise to the customer success team to help them support customers effectively

Drive Technical Execution

• Own and deliver complete features and integrations within our LLM gateway service
• Build and maintain integrations with multiple LLM providers and AI services (OpenAI, Anthropic, Google Vertex, AWS Bedrock etc.)
• Write clean, maintainable, well-tested code following best practices
• Design and implement scalable, fault-tolerant solutions with appropriate abstractions
• Proactively identify and address technical debt, reliability issues, and code quality concerns
• Participate in on-call rotation to ensure service reliability and rapid incident response

Elevate Engineering Standards

• Conduct thorough code reviews focused on maintainability, testing, reliability, and architectural concerns
• Ensure proper test coverage across unit, integration, and end-to-end testing levels
• Improve code maintainability and extensibility through targeted refactoring
• Contribute to runbooks, incident postmortems, customer-facing documentation, and knowledge sharing
• Identify bottlenecks and propose solutions to improve team velocity and system reliability

Build and Collaborate

• Work closely with product, customer success, and engineering teams to deliver solutions
• Collaborate with extern