Senior Backend Engineer, Multiple Accounts

We're looking for a Senior Backend Engineer to join the Multiple Accounts team in the Security domain at Vinted Marketplace. We build account models and registration journeys that support different ways of using Vinted, including helping professional sellers join and grow through Vinted Pro.

The work combines product development, platform thinking, and regulatory complexity. You'll build secure account-lifecycle and linked-account capabilities across all platforms, while improving professional-seller onboarding through business-registry integrations, VAT validation, and Know Your Business requirements. These flows need to be reliable, traceable, and easy for our members to use.

We're a new cross-functional team with significant greenfield work alongside existing systems. We validate product changes through experimentation where appropriate, document important decisions through RFCs, and learn openly from incidents and postmortems. You'll contribute to the technical foundations of how Vinted represents and manages different account types.

• Own features end-to-end: Design, implement, and maintain scalable, reliable, and secure backend systems powering account lifecycles and registration flows for millions of members.
• Guide technical decisions:Take part in system-design reviews, write and review RFCs, and help the team make pragmatic trade-offs between delivery, reliability, and long-term maintainability.
• Build compliance-critical systems: Design flows and integrations where correctness, traceability, and legal/data-protection/KYB compliance are non-negotiable - collaborating closely with Legal, Trust, and Payments.
• Integrate third parties:Build and maintain robust integrations with external business-registry and verification APIs, handling rate limits, validation, and graceful failure.
• Scale features globally: Ship features across international markets and validate member-facing changes through experimentation where appropriate.
• Own your services:Monitor and improve backend service performance and stability, define and track SLIs/SLOs, and participate in the team's alerting and incident response, including post-mortems.
• Collaborate cross-functionally: Work closely with your PM, Product Designer, Decision Scientist, QA, and the Web/iOS/Android engineers in the team, as well as adjacent teams in Payments, Trust & Safety, and Registration.
• Support the engineers around you:Share knowledge, provide thoughtful feedback, and help teammates grow through code reviews, pairing, and onboarding.

• You have strong backend engineering experience and a track record of building reliable systems and owning work from design through production.
• You know at least one programming language deeply and can transfer that knowledge to unfamiliar languages and ecosystems. Ruby, Ruby on Rails or Go experience is helpful, but not required.
• You're comfortable working with APIs, relational and in-memory databases, and service-based systems. Our stack includes Ruby on Rails, Go, MySQL/Vitess, Redis, and Kafka.
• You can build dependable integrations around external systems, including validation, rate limits, failure handling, and incomplete or inconsistent data.
• You care about observability and operational ownership, including monitoring, SLIs/SLOs, incident response, and learning from failures.
• You're curious and adaptable. You're comfortable saying "I don't know yet," learning a complex domain, and applying your existing engineering judgement to it.
• You document important decisions and communicate technical trade-offs clearly to both engineering and non-technical partners.
• You share knowledge, provide constructive feedback, and help the people around you do their best work.
• You use AI-assisted development tools thoughtfully and are interested in finding new ways to improve engineering quality and effectiveness.
• You have excellent written and spoken English.

Nice to have

• Experience with multiple-account models, professional-seller onboarding, identity systems, or Know Your Business processes is valuable, but it isn't required. We care more about your ability to learn a complex domain and build dependable systems within it.

• 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
• Confidential Employee Assistance Program (EAP) for you and your family
• Frequent team-building events
• A personal monthly budget for shopping on Vinted
• The opportunity to spend up to 90 days per year - 21 of which can be spent working outside of the EU - on workation
• 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