Staff Machine Learning Scientist, Ranking

Depop is looking for a talented Staff ML Scientist to join our Ranking ML team in the UK. You will work alongside a cross-functional team of Product Managers, ML Engineers, and fellow ML Scientists, helping build and maintain ranking models to power Depop's app, serving millions of personalised results to users daily. As a staff-level member of the team, you will be expected to set the technical vision, lead high-impact initiatives, and mentor and coach others to drive innovation at scale, while working across multiple domains and stakeholders.

Responsibilities

• Lead the design and deployment of advanced ranking models for Depop's entire app, covering personalised recommendations, search results and other surfaces.
• Collaborate closely with cross-functional partners (product, engineering, data) to define problems, translate them into scalable solutions, and deliver measurable business outcomes.
• Lead the end-to-end lifecycle of ML projects: from ideation, data acquisition, feature engineering, training, and evaluation to deployment and ongoing iteration.
• Drive innovation in ranking by researching and integrating emerging ML techniques, frameworks, and tooling, while contributing technical expertise to long-term product and data strategy.
• Mentor, coach, and set technical direction within the Ranking ML team, helping others grow and innovate.
• Act as a thought leader in the ranking space, sharing learnings internally, engaging with the wider ML community, and showcasing our work externally.

Qualifications

• Significant experience working as a Machine Learning Scientist, with a proven track record of delivering and scaling models that solve complex, real-world problems with measurable business impact.
• Proven track record in designing and optimizing learning-to-rank models.
• Deep understanding of machine learning concepts and frameworks.
• Proven ability to productionize ML models and pipelines: from prototyping to deployment, with strong experience in monitoring, iteration, and troubleshooting.
• Advanced programming skills in Python and familiarity with ML frameworks such as PyTorch, TensorFlow, or similar.
• Experience leading projects and mentoring engineers or scientists, with a track record of fostering team growth and technical excellence.
• Excellent communication skills: able to bridge technical and non-technical stakeholders and influence decision making.
• Committed to responsible AI practices, including attention to ethics, fairness, and inclusivity.

Additional information

• Health + Mental Wellbeing: PMI and cash plan healthcare access with Bupa, subsidised counselling and coaching with Self Space, Cycle to Work scheme with options from Evans or the Green Commute Initiative, Employee Assistance Programme (EAP) for 24/7 confidential support, Mental Health First Aiders across the business for support and signposting.
• Work/Life Balance: 25 days annual leave with option to carry over up to 5 days, 1 company-wide day off per quarter, Impact hours: Up to 2 days additional paid leave per year for volunteering, fully paid 4 week sabbatical after completion of 5 years of consecutive service with Depop.
• Flexible Working: MyMode hybrid-working model with Flex, Office Based, and Remote options (role dependant), all offices are dog-friendly, ability to work abroad for 4 weeks per year in UK tax treaty countries.
• Family Life: 18 weeks of paid parental leave for full-time regular employees, IVF leave, shared parental leave, and paid emergency parent/carer leave.
• Learn + Grow: Budgets for conferences, learning subscriptions, and more, mentorship and programmes to upskill employees.
• Your Future: Life Insurance (financial compensation of 3x your salary), pension matching up to 6% of qualifying earnings.
• Depop Extras: Employees enjoy free shipping on their Depop sales within the UK. Special milestones are celebrated with gifts and rewards!