Principal Machine Learning Engineer London, England, United Kingdom

We are hiring a Principal Machine Learning Engineer to work on cutting-edge Research & Development. As innovators in speech technology, our mission is to Understand Every Voice—a vision that has propelled us to be world leaders of Voice AI, with STT, TTS, and Flow; our brand new Conversational AI platform. Fuelled by innovation, inclusivity, and a passion for making a global impact through world-leading Speech AI, we’re looking for an experienced Machine Learning Engineer to accelerate our efforts towards exceptional speech solutions.

Our Modelling Team trains diverse models, including large self-supervised ones, supporting Speechmatics towards being the most accurate speech recognition system globally. It also ensures their deployment into production, working with the latest developments in ML, but also with the best engineering practices for software engineering and model serving.

What you’ll be doing:

• Drive diverse groups of engineers to achieve ambitious goals; you will work on complex R&D projects, and guide others by defining research milestones and collaborating together.
• Raise the bar for machine learning at Speechmatics, by applying your innovative ideas and experiences to improve the efficiency, effectiveness, and best practices across all of our machine learning teams.
• Set a forward-thinking vision for Speechmatics' business as a world leader in Voice AI; with your passion and understanding of the latest machine learning developments, you will influence our product and technical direction.
• Grow the engineers around you through mentorship and support, ensuring we are all continuously improving together.
• This position allows you to influence what the ML team is working towards, and to efficiently leverage other engineers to increase the output of your experience.

Who we are looking for:

• Someone who can act as a tech lead and use their experience to be not only an example for their coworkers, but also a guardrail.
• Demonstrated experience in collaboratively pursuing ambitious R&D agendas.
• Balances attention to detail with a view on the big-picture, long-term company vision, and is able to relate company goals to the goals of the team members they work with.
• Deep understanding of the modern Machine Learning stack, for example:

• Knowledge of contemporary transformer architectures (e.g., GQA, KV-caching) and best practices.
• Expertise in distributed training techniques.
• Familiarity with optimisation strategies for model inference (e.g., dynamic batching, flash attention, speculative decoding).

• Publications in top-tier conferences.
• Contributions to popular open-source repositories.
• Exceptional technical writing skills as evidenced by relevant publications or blogs.

We encourage you to apply even if you do not feel you match all of the requirements exactly. The list of requirements is intended to show the kinds of experience and qualities we’re looking for, but it is not exhaustive. If you are interested in the role, the team, and our mission, we would love to consider your application. We are always open to conversations and look forward to hearing from you.

Who we are:

Speechmatics is the leading expert in Speech Intelligence, and uses AI and Machine Learning to unlock business value in human speech worldwide. We work with an amazing mix of global companies, and our technology can integrate into our customers stack irrespective of their industry or use case – making it the go-to solution to harness useful information from speech. Joining us means working with some of the smartest minds around the world, focused on cutting-edge projects and deploying the latest techniques to disrupt the market.

We believe in putting people first; we’ll do all we can to help you develop your skills and give you the tools you need to thrive. Our Focus Fridays give you an undisturbed day of focus, offset with Together Tuesdays when we have our team meetings, so you’ve always got the right balance. We have structured a hybrid approach that includes 2-3 designated office days each week. This arrangement ensures that while we embrace the advantages of remote work, we also maintain the vital connection and synergy that only in-person interactions can foster.

What we can offer you:

• No matter what stage of your career you’re at - from paid internships and first-job opportunities through to management and senior positions - we’ll support you with the training and development needed to reach your career aspirations with us.
• There really is no shortage of opportunities here for you to get involved and collaborate with those around you to deliver your best work.
• We offer incredibly flexible working, regular company lunches, and birthday celebrations.
• We’ve spoken to our teams to find out what they want. From Private Medical, and Dental for you and your family, through to global working opportunities, a generous holiday allowance and pension/401K matching, we want to make sure our employees and their families are looked after.
• Every employee will receive a working from home allowance for tech or home office equipment (on top of your choice of laptop and accessories of course).
• Our approach to parental leave is designed to support employees globally. While this varies by geo, we have support in place for parents (including adoption assistance and reproductive health services) to ensure they have the time and financial resources needed to care for their growing families.

At Speechmatics, our mission is simple: Understand Every Voice out there. That’s not just about our tech – it’s the heart and soul of who we are. We welcome different experiences, viewpoints, and identities. For us, it’s not just the right thing to do; it’s our catalyst for sparking innovation and creativity. Our teams thrive in an environment that celebrates and supports everyone – no matter their gender, identity or expression, race, disability, age, sexual orientation, religion, belief, marital status, national origin, veteran status, pregnancy, or maternity status. But we don’t just open the door to diversity – we actively welcome it. Why? Because we believe every unique voice adds something special to our team, leading us to smarter solutions and a better workplace. So, come as you are and join our Speechling community. We’re building a place where every voice not only gets heard but is also respected and valued.