Senior Backend Engineer, Trust & Safety

Brief info about Vinted 

Our mission is to make second-hand the first choice, and we're looking for people who want to help us get there. Every day, we work together to help our members buy and sell pre-loved clothing and lifestyle items, giving each piece a second life - or even a third.

The Vinted Group is made up of three business units that support this mission:

Vinted Marketplace is Europe’s leading platform for second-hand fashion and a go-to destination for all kinds of pre-loved items, with a growing range of categories. Our platform connects millions of members across 20+ markets, helping great items find a new life.

Vinted Go enhances the shipping experience with a vast network of over 500,000 pick-up and drop-off points, partnering with more than 60 carriers across Europe, with added services like item verification for peace of mind on high-value pieces.

Vinted Pay is the newest part of the Vinted Group, dedicated to bringing secure, reliable payments to buyers and sellers across Europe. Seamlessly integrated into the Vinted app, it helps keep every transaction safe, efficient, and easy for our members.

Founded in 2008 in Lithuania, Vinted began as a way for friends to find new homes for clothes they no longer needed. In 2019, we became Lithuania's first unicorn! Today, our headquarters remain in Vilnius, and we've grown with offices across Europe, supported by a team of over 2,000 people. 

Information about the position 

As a Senior Backend Engineer II in the Zen team, you will be responsible for building the systems that help keep counterfeit items off Vinted, while protecting legitimate sellers.

Zen sits in the Trust domain and owns the counterfeit detection problem end to end, not just the tools. We combine rules, machine learning and modern AI to find counterfeit listings, understand where detection falls short and keep improving it. The work has a direct impact on how safe and trustworthy Vinted is for our members, and we're growing our use of AI to make that protection work at Vinted's scale.

We work with Go, Ruby and Python, alongside ML models and LLMs.

In this position, you’ll 

• Design and build the backend services behind counterfeit detection.
• Spot new counterfeiting patterns early and turn them into new detection capabilities.
• Take technical ownership of complex projects, from idea to production, including writing RFCs and making architecture decisions.
• Build AI-driven capabilities, including LLM-based systems, that are reliable, observable and cost-aware.
• Collaborate with data and decision scientists, using data to make decisions and bringing engineering input to how detection and models are improved.
• Measure the impact of what we ship, with accuracy and fairness to legitimate sellers in mind.
• Raise the bar for engineering and agentic development by mentoring engineers in the team and beyond.

About you 

• Proven experience designing, building and operating ML- and data-driven backend systems in production, with Go, Ruby or Python, including event-driven systems.
• Curiosity and drive to explore and apply AI to counterfeit detection, staying on top of the latest developments in LLMs and their practical applications.
• Solid understanding of data, ML and LLMs: how models are trained, evaluated and retrained, and how to build reliable systems around them.
• Comfortable working with data and decision scientists, using data to make decisions and contributing valuable engineering input.
• Demonstrated ability to own complex, ambiguous problems end to end and drive technical decisions.
• Pragmatic about trade-offs between catching abuse and protecting legitimate sellers, and able to explain technical decisions to non-engineers.
• Advantage: 
• Bonus: experience with BigQuery, Vespa, Temporal

Work perks 

• The opportunity to benefit from our share options programme
• 25 working days of holiday
• Access to all the tools & tech needed for work
• Home office support: we provide IT workstation equipment and a personal budget of up to €540 for home workplace furniture
• Private health insurance
• Pension plan with flexible contribution options and a matching contribution from Vinted
• Confidential Employee Assistance Program (EAP) for you and your family
• Frequent team-building events
• A personal monthly budget for shopping on Vinted
• A dog-friendly office
• In Vilnius office: Gym & in-house meals at friendly prices
• In Kaunas office: a monthly lunch allowance, and a once-a-week provided in-house lunch and breakfast

Working at Vinted 

Workation policy

Better balance holidays with workdays by working remotely! Up to 90 days per year in the EU, of these, 21 days can be spent globally. For non-EU citizens, it's 21 days worldwide. This can be combined with time off for vacation or personal time.

Individual learning budget

Each year, you’ll be given a learning budget (starting at €3,000), and a total of up to 10 working days over a 2-year period to support your personal and professional development.

Hybrid work

Our hybrid model, with 2 recommended office days a week, gives you and your team the flexibility to decide if and when you want to work from home, and when to catch up in person.

Equal opportunity

We welcome applications from everybody, regardless of your background, identity, or life experiences. Job openings come with guides, not checklists. If you’re excited about a role, but don’t identify with every point in the ‘About you’ section, apply anyway - you might still be the perfect match!

The gross monthly salary range for this position is:

€6.900—€9.333 EUR