Senior Backend Engineer - Trust Detection

About the role

Depop’s Trust Detection squad builds proactive, scalable detection systems that identify harmful content and user behaviour early, enabling fast, fair and effective moderation at scale. As a Senior Backend Engineer in Trust Detection you will shape, evolve and scale these detection capabilities, working closely with ML engineers, scientists and cross‑functional partners.

Responsibilities

• Independently design and deliver backend solutions to medium‑to‑large problem spaces, from discovery through production and iteration.
• Build and evolve core detection services, pipelines, and APIs that operate at scale and under real‑world adversarial conditions.
• Work hands‑on with ML Engineers and ML Scientists to productionise models and improve detection pipelines, monitoring, and iteration loops.
• Take end‑to‑end ownership of your work, including design, implementation, testing, observability and operational support.
• Contribute to shaping technical direction within the team, improving system design, reliability and developer experience.
• Operate in an experiment‑led environment, helping define hypotheses, success metrics and feedback loops.
• Collaborate closely with Product, Fraud, Trust and Safety and other Engineering teams to ensure solutions are well scoped and well understood.
• Actively contribute to continuous improvement through retrospectives, post‑incident reviews and technical discussions.
• Mentor and support other engineers in the team, raising the overall quality of delivery.

Qualifications

• Strong backend engineering fundamentals with experience independently delivering production systems.
• Proficiency in at least one backend language such as Scala, Java or Python, with the ability to learn new languages quickly.
• Experience working with data‑intensive systems, including designing, consuming and evolving data models across services.
• Experience building or operating event‑driven systems, such as producing and consuming events or messages in distributed architectures.
• Experience building scalable and reliable services and APIs.
• Strong sense of ownership paired with effective collaboration and communication.
• Comfort working in ambiguous problem spaces and proactively shaping solutions.
• Solid testing practices across unit and integration levels.
• Experience working in a DevOps‑oriented environment, including CI/CD and production monitoring.
• Helpful experience with running, maintaining or evolving ML‑powered systems in production.
• Experience in experiment‑led or hypothesis‑driven teams with strong data and insights practices.
• Prior work in Trust and Safety, fraud, abuse detection or moderation systems.
• Experience in marketplace or eCommerce environments.
• Hands‑on experience with message brokers or streaming platforms such as Kafka.
• Experience with Docker and Kubernetes.
• Familiarity with AWS infrastructure and infrastructure‑as‑code tooling.

Benefits

• Health + Mental Wellbeing: PMI and cash plan healthcare access with Bupa, subsidised counselling and coaching with Self Space, Cycle to Work scheme and Green Commute Initiative.
• Employee Assistance Programme (EAP) for 24/7 confidential support and Mental Health First Aiders across the business.
• Work/Life Balance: 25 days annual leave (up to 5 days can be carried over) and one 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 5 years of consecutive service with Depop.
• Flexible working: MyMode hybrid‑working model with Flex, Office‑Based and Remote options (role‑dependent) and the 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 employees, IVF leave, shared parental leave and paid emergency parent/carer leave.
• Learning & Growth: budgets for conferences, learning subscriptions and other up‑skilling programmes.
• Insurance and retirement: Life Insurance (3× your salary), pension match up to 6% of qualifying earnings.
• Depop Extras: free shipping on Depop sales within the UK and special milestone celebrations with gifts and rewards.

EEO Statement

Depop is an equal opportunity employer. We provide employment opportunities without regard to age, ethnicity, religion, gender identity, sexual orientation, disability, pregnancy or maternity or any other protected status. We are open to accommodating all needs you may have. For disability accommodations, please email adjustments@depop.com.