Startup jobs in United Kingdom

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!

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, evaluate and deploy 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.

• 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

• 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

• 5+ years of professional software engineering experience
• Strong proficiency in Python and SQL with demonstrated ability to write production‑quality code
• Solid understanding of software engineering fundamentals:
• Data structures and algorithms
• System design and architectural patterns
• Testing strategies (unit, integration, end‑to‑end)
• Code review practices and technical collaboration
• Experience with:
• RESTful APIs and distributed systems concepts
• Containerization (Docker) and basic cloud infrastructure
• Track record of delivering high‑quality software in a team environment
• Ability to thrive in a startup environment with changing priorities and rapid iteration

• Experience with GCP services (BigQuery, GCS, Cloud Run, GKE)
• Familiarity with distributed processing frameworks (Apache Beam, PySpark)
• Experience with workflow orchestration tools (Airflow, Prefect, Dagster)
• Understanding of ML/AI infrastructure and data pipelines
• Experience with monitoring and observability tools (Datadog)
• Experience working with researchers directly
• Background in data engineering roles

This role requires someone who is:

• Excellent at software fundamentals - You write code that others want to emulate
• Quality‑focused - You care deeply about testing, documentation, and maintainability
• Customer‑aware - You understand how your work impacts research experience and business outcomes
• Collaborative - You work well with diverse stakeholders and help others succeed
• Growth‑minded - You're curious, eager to learn, and want to expand into platform and infrastructure engineering
• Pragmatic - You balance perfection with delivery and understand trade‑offs in a fast paced environment
• Team‑oriented - You improve not just the code, but the team's overall effectiveness
• Reliable - You build systems that customers depend on for their critical operations

We're looking for the best person for this role - someone who can hit the ground running while growing with the team. The ideal candidate brings strong software engineering discipline and is excited to apply those skills to the unique challenges of data engineering at scale to support our model development lifecycle.

AssemblyAI strives to recruit and retain exceptional talent from diverse backgrounds while ensuring pay equity across our team. Our salary ranges are set to be competitive for our size, stage, and industry, and reflect just one component of the full compensation, benefits, and rewards we offer.

Salary determinations consider a variety of factors, including relevant experience, technical depth, skills demonstrated during the interview process, and maintaining internal equity with peers on the team. The range shared below represents a general expectation for the posted position. However, we are open to considering candidates who may fall above or below the outlined experience level—in those cases, we will communicate any adjustments to the expected salary range.

• Germany / Ireland:€141,267 – €184,512
• United Kingdom:£117,159 – £153,024

We set ranges per country to ensure competitive, fair, and transparent compensation across regions. Final offers will vary based on interview performance, experience, skill level, and maintaining internal equity.

Our total compensation package includes competitive equity grants, 100% employer‑paid benefits, and the flexibility of being fully remote.

We are a small but mighty group of startup veterans and experienced AI researchers with over 20 years of expertise in Machine Learning, Speech Recognition, and NLP. As a fully remote team, we’re looking for people to join our team who are ambitious, curious, and lead with integrity. We’re still in the early days of AI and of AssemblyAI’s journey, and are looking for teammates who won’t just fit in, but will help us define and build our company culture.

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!

Using AI to Interview:

If you’re selected for an interview, please review this resource to better understand how AssemblyAI approaches the use of AI in our interview process.

Check us out on YouTube! Learn more about AI models for speech recognition Core Transcription | Audio Intelligence | LeMUR | Try the Playground Our $50M Series C fundraise