Lead Decision Scientist, Security

Vinted group.; Amsterdam; On-site; EUR 90,000 - 150,000; Full time

Benefits offered by this job

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25 days leave

EAP

Team-building

Home office budget €540

Shopping budget

Pension plan

Public transport card

Bike leasing

Job summary

Vinted Group is seeking a Lead Decision Scientist in Security to shape measurement, evaluation, and decision frameworks for restricting malicious activity. You will own the analytical foundation and quantify user friction vs. harm across the full journey.

You’ll partner with Security leadership, mentor data scientists, define the security metric tree, and raise experimentation standards with rigorous causal analyses in complex environments.

Qualifications

• Proven analytical track record in Decision Science or related fields.
• Experience designing metric systems and decision frameworks.
• Strong background in A/B testing and causal inference.
• Structured problem solver with ability to translate open-ended challenges into analytical solutions.
• Excellent collaboration and communication skills.

Responsibilities

• Build decision frameworks for user restrictions based on risk.
• Balance member friction against harm prevention across onboarding.
• Lead cross-team discovery on security challenges and tools vs in-house solutions.
• Own the security metrics tree and target-setting for product and business outcomes.
• Raise experimentation standards and guide causal inference in complex environments.
• Mentor and lead Decision Scientists across Security teams.

Skills

SQL

Python or R

Decision Science

Econometrics

Data analytics

Job description

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

At Vinted, the Security domain protects our marketplace across critical member touchpoints: Registration, Login, User Verification, Bot Prevention, and Authentication & Authorization. Every single member interacts with Security systems before making their first transaction.

As a Lead Decision Scientist in Security, you will serve as the senior technical lead responsible for bringing structure, clarity, and analytical rigor to some of our most critical trade‑off decisions. While our Engineering and Data Science teams build defensive infrastructure and detection models, your focus will be entirely on measurement, evaluation, and decision frameworks.

In Security, every action comes with a trade‑off: stopping malicious actors earlier prevents harm, but intervening too early or aggressively can frustrate or block legitimate members. Today, we have multiple restriction tools available—from verification challenges to account bans—and we need a clear framework to decide when and how to apply each one.

You will act as an autonomous strategic partner to Security leadership. You will own the analytical foundation for how we restrict malicious activity, quantify user friction versus harm prevention, and lead discovery on ambiguous, high‑impact problems across the full user journey.

In this position, you’ll

• Build decision frameworks for user restrictions: Design the logic that determines which restriction measure to apply (such as verification challenges or account bans) based on user risk and context.
• Balance member friction against harm prevention: Quantify the trade‑offs between stopping malicious actors early and keeping the onboarding experience seamless for genuine members.
• Lead strategic cross‑team discovery: Tackle open‑ended questions across the user journey, such as analyzing duplicate/multiple account networks, assessing bot patterns, or evaluating third‑party security tools versus in‑house solutions.
• Own domain metrics and impact measurement: Build and maintain the Security metric tree, guiding target‑setting so product and business strategies are grounded in clear, measurable impact.
• Raise experimentation standards: Guide best practices in A/B testing and causal inference in complex environments where traditional experimentation isn't always straightforward.
• Mentor and lead through influence: Coach embedded Decision Scientists across Security teams, foster a culture of open feedback and continuous learning, and elevate data literacy across the domain.

About you

• Proven analytical track record: Demonstrated experience in Decision Science, Product Analytics, Econometrics, or related quantitative fields, with a history of leading complex analytical projects as a senior individual contributor.
• Decision & trade‑off frameworks: Solid experience designing metric systems and decision frameworks that balance competing objectives under ambiguity.
• Experimentation & causal inference: Strong practical foundation in A/B testing and causal inference.
• Structured problem solver: Comfortable taking open‑ended, complex business challenges and translating them into clear, actionable analytical solutions.
• Collaboration & communication: Great communication skills - able to explain complex concepts simply, challenge assumptions constructively, and guide cross‑functional stakeholders without needing formal authority.
• Technical toolkit: Strong hands‑on proficiency in SQL and Python or R for data analysis and modeling.
• Nice‑to‑have (not required): Previous experience in trust & safety, fraud prevention, risk assessment, cybersecurity, or two‑sided marketplaces.

Studies show that women and members of underrepresented communities often apply for jobs only if they meet 100% of the qualifications. If you don’t recognise yourself in all of the above, you might still be an excellent candidate for this position. If this role excites you, we encourage you to apply.

• The opportunity to benefit from our share options programme
• 25 days of paid annual leave
• Confidential Employee Assistance Program (EAP) for you and your family
• Frequent team‑building events
• Home office support: we provide IT workstation equipment and a personal budget of up to €540 for home workplace furniture
• A personal monthly budget for shopping on Vinted
• Collective Defined Contribution Pension plan
• NS Business Card for your commute to the office by public transport
• Company bike leasing scheme