Principal Machine Learning Engineer, Matching and Recommendations

Salary: £61,000 - 101,000 per year

Requirements:

• Typically requires 10–15 years of experience, though we welcome candidates with alternative backgrounds that demonstrate equivalent skills.
• Deep expertise in machine learning, with hands-on experience building and deploying large-scale systems in production environments.
• Strong proficiency in Python and at least one major ML framework (e.g. PyTorch, TensorFlow), with experience in areas such as recommendation systems, ranking models, or NLP.
• Expertise in prompting and fine-tuning Large Language Models (LLMs) and building production AI Agents.
• Proven experience designing scalable data and ML pipelines using tools such as Spark, Airflow, or similar distributed systems.
• Demonstrated ability to operate as a senior individual contributor, influencing technical strategy and decision-making without direct authority.
• Experience partnering effectively across functions, collaborating with purpose and taking ownership of outcomes in complex organisational environments.
• A track record of mentoring and uplifting others, role modelling Respect and Excellence while building inclusive, high-performing teams.
• Strong AI fluency, with the ability to independently design, evaluate, and optimise ML systems, and guide others in the responsible and effective application of AI.

Responsibilities:

• Define and lead the technical strategy for AI and Machine Learning systems that power recommendations, ranking, and personalization across our products, delivering measurable improvements in user engagement and safety.
• Design, develop, and deploy production-grade models using modern ML frameworks such as PyTorch, ensuring scalability and reliability in high-traffic environments.
• Build and deploy production AI Agents using raw and fine-tuned foundational Large Language Models (LLMs), along with sub-agents, tools, and MCP integrations.
• Architect end-to-end ML pipelines, integrating data processing (e.g. Spark, Airflow) with model training, evaluation, and deployment workflows.
• Drive experimentation frameworks, including A/B testing and offline evaluation, to continuously improve model performance and product outcomes.
• Partner cross-functionally with Product, Engineering, and Data leadership to translate business challenges into impactful ML solutions, collaborating with purpose and influencing at senior levels.
• Mentor and elevate senior individual contributors, fostering a culture of Excellence, Curiosity, and continuous learning across the ML community.
• Take ownership of complex, ambiguous problem spaces, seeing initiatives through from insight to impact while adapting approaches with an agile mindset.
• Champion responsible AI practices, ensuring fairness, transparency, and user safety are embedded into all machine learning systems.

Technologies:

• AI
• AI Agents
• Airflow
• Architect
• Embedded
• Fine-tuning
• Support
• Machine Learning
• MCP
• Mobile
• Model Training
• PyTorch
• Python
• Spark
• TensorFlow
• Web

More:

We are Bumble Inc., the parent company of Bumble Date, BFF, and Badoo, and our platform helps people build healthy and equitable relationships through Kind Connections. Founded by Whitney Wolfe Herd in 2014, we were one of the first dating apps built with women at the center and we connect people across dating and friendship. BFF is our friendship app for meeting nearby people and building meaningful platonic connections based on shared interests, and Badoo, founded in 2006, is one of the pioneers of web and mobile dating products. This is a hybrid role based in London. We offer an annual personal learning and development budget, Private Medical Insurance, Private Dental Insurance, the Babylon Health app, mental health support, enhanced parental leave including a highly competitive maternity package, unlimited PTO, subsidised gym membership, double matched pension contributions up to 6%, and Premium App Access. We are an equal opportunity employer and encourage people of all ages, colour, lesbian, gay, bisexual, transgender, queer and non-binary people, veterans, parents, people with disabilities, and neurodivergent people to apply. We also use AI tools to support parts of our recruitment process, while all hiring decisions are made by people.

last updated 36 week of 2026