Principal Machine Learning Engineer

We are hiring a Principal Machine Learning Engineer to work on cutting-edge R&D and translating research into customer-centric solutions.    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. Fuelled by innovation, inclusivity, and a passion for making a global impact through world-leading Speech AI, we're looking for an experienced Principal 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.  This is a hands-on, technical leadership role with high ownership.  You will develop and deploy advanced speech systems that power our products as well as co-define the technical vision for ML, drive innovation, and mentor engineering teams. Your work will span the entire codebase.     What You’ll Do: * Develop and deploy ML models, translating research into scalable, maintainable code and services  * Optimise ML models for speed, accuracy, and cost efficiency  * Evaluate and integrate cutting-edge approaches into our ML stack * Identify and solve complex ML problems across the organisation * Define and enforce best practices for code quality, model lifecycle management, etc. * Mentor engineers and foster a culture of technical excellence and innovation * Co-define the long-term technical vision  What We’re Looking For: * 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) * Proven track record of developing and deploying models at scale * Expertise in Python, ML frameworks (TensorFlow, PyTorch), and experience with cloud platforms * Strong familiarity with MLOps principles, CI/CD pipelines, and containerization (Docker, Kubernetes)   With preferred backgrounds covering some of the following: * Experience with speech-to-text or text-to-speech  * Contributions to open-source projects or published research in top-tier conferences 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. This is only the beginning; we’re looking for amazing people like you to continue our journey… 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. But that’s not all. 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. For more information on us, please visit our website and follow Speechmatics on our social channels via Twitter, Facebook, LinkedIn, and YouTube. WE RELY ON LEGITIMATE INTEREST AS A LEGAL BASIS FOR PROCESSING PERSONAL INFORMATION UNDER THE GDPR FOR PURPOSES OF RECRUITMENT AND APPLICATIONS FOR EMPLOYMENT.  #LI-HYBRID

Toast creates technology to help restaurants and local businesses succeed in a digital world, helping business owners operate, increase sales, engage customers, and keep employees happy. Toast is looking for a hands-on Principal Software Engineer to join the AI & Strategy Engineering team. In this role, you will be a primary builder of 0-to-1 tools designed to revolutionize how our sales teams operate. This isn't about maintaining legacy systems; it’s about writing the code and building the intelligence models that eliminate friction across the Go-To-Market stack. Working under a Senior technical leader, you will be responsible for the "heavy lifting" of backend engineering and Machine Learning implementation. You will bridge our custom quoting software and Salesforce with intelligent, agentic workflows that allow sales users to make faster, data-backed decisions.   A day in the life (Responsibilities)  * Hands-on Execution: Spend the majority of your time "hands-on-keyboard," architecting and coding high-performance backend services and ML pipelines. * 0-to-1 Development: Build and prototype new internal products from scratch that leverage LLMs and Agentic AI to automate account research, lead prioritization, and complex quoting logic. * Core Intelligence Models: Design and implement ML models that provide real-time recommendations to sales users, reducing manual entry and increasing deal velocity. * Infrastructure Integration: Develop the backend connective tissue between our custom quoting engine, Salesforce, and internal data lakes to ensure a seamless, low-latency end-to-end experience. * Technical Problem Solving: Act as a domain expert to solve complex synchronization and architectural challenges across the GTM stack, ensuring systems are scalable and resilient. * Quality & Mentorship: Drive engineering excellence through rigorous code reviews, automated testing, and by modeling best practices for SE1-SE3 engineers on the team. * Build Great Products: Deliver significant core capabilities that have broad impact; take high-level goals and turn them into sequenced, production-ready code. * Problem Solve: Anticipate shifts in product needs and build flexible, decoupled backend systems that can evolve with our AI strategy. * Deliver Quality: Ensure the reliability of GTM tools by building deep observability into every service you ship.   What you'll need to thrive (Requirements) * Deep Backend Expertise: Extensive experience in backend languages (Java, Go, Python) with a track record of building complex, distributed systems. * Applied AI/ML Skills: Practical, hands-on experience deploying Machine Learning models and building with LLMs (e.g., LangChain, RAG architectures, or Model Fine-tuning) in a production environment. * Technical Complexity: Experience building or deeply integrating with complex enterprise software, specifically custom quoting engines or CRM internals (Salesforce Apex/LWC). * Systems Architecture: Ability to design event-driven architectures and manage data flow across disparate systems with high integrity. * Education: Bachelor’s or Master’s degree in Computer Science, or a related technical field.   What will help you stand out (Nonessential Skills/Nice to Haves) * Experience building internal "Sales Tech" or "Fintech" tools that directly impact revenue. * Familiarity with AWS data services (SageMaker, Lambda, SQS). * A passion for removing "human-in-the-loop" friction through intelligent automation.   AI at Toast At Toast, one of our company values is that we're hungry to build and learn. We believe learning new AI tools empowers us to build for our customers faster, more independently, and with higher quality. We provide these tools across all disciplines, from Engineering and Product to Sales and Support, and are inspired by how our Toasters are already driving real value with them. The people who thrive here are those who embrace changes that let us build more for our customers; it’s a core part of our culture.   Our Total Rewards Philosophy  We strive to provide competitive compensation and benefits programs that help to attract, retain, and motivate the best and brightest people in our industry. Our total rewards package goes beyond great earnings potential and provides the means to a healthy lifestyle with the flexibility to meet Toasters’ changing needs. Learn more about our benefits at https://careers.toasttab.com/toast-benefits. #LI-Remote The base salary range for this role is listed below. The starting salary will be determined based on skills, experience, and geographic location. In addition to base salary, our total rewards components include cash compensation (overtime, bonus/commissions if eligible), equity, and benefits. You can learn more about how we align pay with local labor markets in our Geographic Pay Zone Philosophy. Zone A $230,000—$368,000 USD Zone B $200,000—$320,000 USD Zone C $180,000—$288,000 USD How Toast Uses AI in its Hiring Process Throughout the hiring process, our goal is to get to know you. We use AI tools to support our recruiters and interviewers with tasks like note-taking, summarization, and documentation of interviews to ensure they can be fully focused on your conversation. All hiring decisions are made by people. To learn more: https://careers.toasttab.com/ai-in-hiring Our Approach to Hybrid Working We embrace a hybrid work model that fosters in-person collaboration while valuing individual needs. Our goal is to build a strong culture of connection as we work together to empower the hospitality community, regardless of location. Please visit the Locations page on our career site to learn more about our in-office expectations by region: https://careers.toasttab.com/locations-toast Diversity, Equity, and Inclusion is Baked into our Recipe for Success At Toast, our employees are our secret ingredient—when they thrive, we thrive. The restaurant industry is one of the most diverse, and we embrace that diversity with authenticity, inclusivity, respect, and humility. By embedding these principles into our culture and design, we create equitable opportunities for all and raise the bar in delivering exceptional experiences. We Thrive Together We embrace a hybrid work model that fosters in-person collaboration while valuing individual needs. Our goal is to build a strong culture of connection as we work together to empower the restaurant community. To learn more about how we work globally and regionally, check out: https://careers.toasttab.com/locations-toast. Apply today! Toast is committed to creating an accessible and inclusive hiring process. As part of this commitment, we strive to provide reasonable accommodations for persons with disabilities to enable them to access the hiring process. If you need an accommodation to access the job application or interview process, please contact candidateaccommodations@toasttab.com. ------ For roles in the United States, it is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.