Senior Backend Engineer

What you´ll do:As an embed Senior Backend Engineer, you’ll:Migrate hundreds of millions of legacy users to the new system, automatically claiming existing usernames while safely handling validation errors and edge casesImplement fallback logic for users who never set a username, ensuring every account has a unique and valid identifier.Provide immutable, unrecognizable URL identifiers that can be safely used as public-facing profile links.Integrate username and identifier generation into the account lifecycle, ensuring that every new account automatically receives a unique username and corresponding URL identifier.Work with data pipelines and large-scale processing systems to ensure reliable, performant migration and synchronization of identity data.Collaborate with engineers and PMs across User Platform, Social, and Client orgs to ensure seamless integration, scalability, and safety.Who You AreA Senior Backend Engineer experienced in designing, building, and operating large-scale distributed systems in Java.Skilled at writing clean, maintainable, and testable code, with a strong focus on system reliability and performance.Experienced in designing for scalability, resilience, and observability, with hands-on experience managing large volumes of data.Able to lead technical design discussions, influence architecture, and collaborate effectively across multiple teams and domains.Comfortable taking end-to-end ownership of complex projects — from design and implementation to production and maintenance.Pragmatic, outcome-oriented, and able to balance technical quality, delivery speed, and user impact.Passionate about user identity, data integrity, and building robust backend systems that support safe and social user experiences.Start/End: 2025-12-01 to 2026-02-28 possible extensionWorkplace: Remote in Sweden