Senior Backend Engineer - Trust Detection

Team: Engineering & Data

Location: Depop - London

Company Description

Depop is the community-powered circular fashion marketplace where anyone can buy, sell and discover desirable secondhand fashion. With a community of over 35 million users, Depop is on a mission to make fashion circular, redefining fashion consumption. Founded in 2011, the company is headquartered in London, with offices in New York and Manchester, and in 2021 became a wholly-owned subsidiary of Etsy. Find out more at www.depop.com Our mission is to make fashion circular and to create an inclusive environment where everyone is welcome, no matter who they are or where they’re from. Just as our platform connects people globally, we believe our workplace should reflect the diversity of the communities we serve. We thrive on the power of different perspectives and experiences, knowing they drive innovation and bring us closer to our users. We’re proud to be an equal opportunity employer, providing employment opportunities without regard to age, ethnicity, religion or belief, gender identity, sex, sexual orientation, disability, pregnancy or maternity, marriage and civil partnership, or any other protected status. We’re continuously evolving our recruitment processes to ensure fairness and are open to accommodating any needs you might have. If, due to a disability, you need adjustments to complete the application, please let us know by sending an email with your name, the role to which you would like to apply, and the type of support you need to complete the application to [email protected]. For any other non-disability related questions, please reach out to our Talent Partners.

Life is about creating. That's why we're home to over 30 million artists, stylists, designers, sneakerheads — and you? We're the community-powered, circular-minded marketplace changing the world of online fashion. Now it's time to get inspired at Depop.

Responsibilities

Job description
Depop’s Trust Detection squad plays a critical role in keeping our global community safe. We build proactive, scalable detection systems that identify harmful content and user behaviour early, enabling fast, fair, and effective moderation at scale.

This is a cross-functional squad of Backend and Machine Learning Engineers working closely with Product, Data, Fraud and Trust and Safety partners. The team operates in a rapidly evolving problem space where threats change quickly and systems must continuously adapt.
As a Senior Backend Engineer in Trust Detection, you will have a unique opportunity to shape, evolve, and scale our detection capabilities. You will work on systems that are still maturing, influence how we productionise ML, and help establish strong engineering foundations as the domain grows.

This role suits engineers who enjoy autonomy, are deeply curious, and thrive in collaborative, ambiguous problem spaces.

What you will be doing
  • 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

Why this role is exciting
  • You will help shape and scale detection systems that are still evolving rather than joining a fully fixed platform
  • You will work closely with ML Scientists without needing to be an ML specialist
  • You will have real ownership over meaningful problem areas
  • You will see direct, measurable impact from your work on the safety of millions of users
  • You will join a team that values experimentation, learning, and pragmatic engineering excellence
     
What are we looking for
Core requirements
  • 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
  • A 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, but we value learning just as much
  • Experience 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 or similar technologies
  • Experience with Docker and Kubernetes
  • Familiarity with AWS infrastructure and infrastructure-as-code tooling
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, to give you a chance to recharge or do something you love. 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!

How we work

MyMode is our new hybrid-working model, designed to empower our employees to choose a working mode that works for them.

MyMode is composed of 3 working modes: Flex, Office Based and Remote.

Flex (Default)

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Flex is our default working mode, meaning all employees will automatically enrol in this mode and there is no application required to enter this mode. Flex employees will be expected to work from the office at least 4 days per month. Teams will determine whether there are set weekly or monthly in-office days based on their operating rhythms and practices. You will need to work with your manager to determine your in-office schedule for your team.

Office Based

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This option is for employees who are committing to work from the office for a minimum of 4 days per week. As part of taking on the Office Based working mode you will be able to apply for a permanent desk in the office if you need one, but you won’t need to apply to become an Office Based employee.

Remote

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Under the Remote working mode you are able to work anywhere within the country you are employed in. This mode requires around 2- 4 days per year in the office, depending on organisational guidance. You will be able to expense travel if you are asked to attend the office, but not for office attendance by your choice.

*Remote working is not applicable for all roles at Depop, please check with our Talent Team.

How We Care

  • Your health
    Tell me more
    • Enhanced Maternity + Paternity Leave, plus adoption leave, IVF leave, shared parental leave + paid emergency parent/carer leave
    • Private Healthcare (UK and US) - choice of a healthcare plan that best suits you
    • Subsidised counselling through Selfspace
    • Employee Assistance Programme (EAP)
    • Mental Health First Aiders across the business
    • Life Insurance
    • Pension
  • Your balance
    Tell me more
    • 25 days annual leave plus bank holidays
    • 1 company-wide day off per quarter, for you to take some time for yourself and decompress
    • Impact hours to be used for volunteering, demonstrations or internal initiatives
    • Apply to work abroad 4 weeks of the year (in UK tax treaty countries)
    • Fully paid 4 week sabbatical after completion of 5 years of consecutive service with Depop, to give you a chance to recharge or do something you love.
  • Your growth
    Tell me more
    • Budgets for conferences, learning subscriptions and more
    • Learn new perspectives from other people in the company with our mentoring programme
    • Promoting inclusion and diverse viewpoints with DEI training
    • Upskilling our employees with year-long programming like manager training, workshops, conferences and meetups

Location

20 Farringdon Rd

EC1M 3HE

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Application Process

  • Stage 1: Talent Partner Call

    This initial stage is a general conversation about your background, skills and what you’re looking for in your next role. You’ll gain further insight into life at Depop and the opportunity at hand.

  • Stage 2: Hiring Manager Call

    The Hiring Manager is most likely the person you’d report into at Depop, so they’ll be delving deeper into your experience. This is another opportunity to learn more about the team’s mission and goals.

  • Stage 3: 1st Stage Interview

    This interview is centred around assessing your role-specific skills, usually in the form of a paired-programming sesion, whiteboard session or presentation (depending on the role). You’ll meet with peers at Depop who can guide you through your day-to-day responsibilities in the role and answer any of your more technical questions.

  • Stage 4: Final Interview

    Our final interviews are usually made up of an executive interview with a senior stakeholder. In this session, we'll dive even deeper into your working styles and the type of culture you thrive in, as well as provide you with more information around our mission as a company and how your role would contribute to this.

    *Please note that the order of this process may be subject to change, based upon certain requirements or circumstances. If this is the case, you will be notified at the beginning of your process.

Our DNA encompasses the central reasons that people are proud to work at Depop and unites us with a shared language and sense of community.

It guides our daily interactions and empowers individuals, teams, departments and our company as a whole to have a greater impact and achieve our mission.

Show up for the community

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We go above and beyond. When they succeed, we succeed.

We’re changing how millions of people buy, sell and explore their style, so we do everything we can to create a safe space in a community where you can learn, grow and succeed on your own terms.

Have each other's backs

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We empower each other with kindness and respect our differences.

Everyone at Depop is seen, heard, valued and encouraged. Our genius is born from our diversity of thought, so we celebrate our wins together and hold each other up when things get tough.

Act with purpose

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We take conscious risks, deliver efficiently and learn from our mistakes.

Our mission is to be the world’s most diverse and progressive home of fashion. We have the conviction to succeed, the patience to learn and the confidence to fail and try again - being open all the way.

Think thrift

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We’re resourceful, seek out opportunities and we hustle.

We’re powering a future that is more thoughtful, circular and better for people and planet. To do it, we stay curious, savvy, resourceful and empowered to get the job done – effectively and responsibly.

At the heart of our mission...

Winking gif

INCLUSION

Fashion is global. It’s for everyone. So, we’re building a diverse ecosystem at Depop where everyone is seen, heard, valued and empowered to succeed. We’re working towards a future where DEI is at the heart of everything that we do. When you succeed, we succeed.

COMMUNITY

We know culture is felt, rather than told. But at Depop, you'll find a place where everyone can bring their own style to everything they do. We keep it circular as we recognise our impact on our community of sellers, our users, on the planet and on the future of fashion.

SUSTAINABILITY

Together, we’re shaping a new circular fashion system. One that’s kinder to people and to the planet. It’s simple. But it’s massive, too. It helps the environment, builds new connections and creates new ways to experience clothing.

At the heart of our mission...

Winking gif

INCLUSION

Fashion is global. It’s for everyone. So, we’re building a diverse ecosystem at Depop where everyone is seen, heard, valued and empowered to succeed. We’re working towards a future where DEI is at the heart of everything that we do. When you succeed, we succeed.

COMMUNITY

We know culture is felt, rather than told. But at Depop, you'll find a place where everyone can bring their own style to everything they do. We keep it circular as we recognise our impact on our community of sellers, our users, on the planet and on the future of fashion.

SUSTAINABILITY

Together, we’re shaping a new circular fashion system. One that’s kinder to people and to the planet. It’s simple. But it’s massive, too. It helps the environment, builds new connections and creates new ways to experience clothing.