senior full-stack engineer

What We Need A senior full-stack engineer to embed in the team for 6 months and deliver across the squad's full surface area - backend services, web and client-facing surfaces, data pipelines, and experimentation infrastructure. This person will operate as a strong individual contributor within the squad - writing code, shipping features, improving the platform - and should be able to ramp up quickly in a complex, high-stakes codebase where changes directly affect subscription conversion. Scope of Work The specific deliverables will be refined during onboarding, but the engagement is expected to span the teams full surface area: Building and improving Checkout surfaces, primarily web, with awareness that the team also supports Android Backend work on the services that power Checkout flows - including serving layer, API design, and integration with platform infrastructure on GCP Contributing to experimentation and A/B testing infrastructure across frontend and backend Implementing personalisation features that improve the purchase experience Improving observability, instrumentation, and data pipelines that feed funnel analysis and experimentation Working with data engineers and analysts to ensure experiments are properly instrumented and measured Technical Profile Backend - very strong Java, distributed services on GCP. Deep ability to architect and own services operating at scale. Experience with commerce/subscription system complexity - state machines, downstream constraints, backward compatibility, and reliability at scale. Able to reason about the full system from backend through serving layer to client surface. Frontend - very strong TypeScript, component architecture at scale, state management, web performance, frontend observability. Understands how loading states, error handling, form design, and perceived performance influence whether a user completes a purchase. Comfortable building for experimentation and A/B testing at the frontend layer. Client - awareness Not expected to write native code, but should be aware that the team supports Android development and that decisions in the backend and serving layer manifest differently across platforms. Enough understanding to reason about platform constraints and collaborate with engineers working on the native side. Data - acquainted Acquainted with data pipelines, instrumentation, and funnel analysis. Able to investigate, validate, and prioritise using data, and to ensure experiments are properly instrumented and measured. ML - awareness Enough familiarity with ML systems to collaborate meaningfully with ML engineers on integration into the Checkout experience. What We're Looking For Proven ability to ship in a complex, high-traffic product codebase with minimal ramp-up time Product awareness - thinks about the user, not just the implementation Holistic approach to the Freemium Funnel - understands that Checkout is one step in a larger journey and builds with that broader context in mind Comfortable working within an established architecture and team norms rather than reshaping them Self-directed within a defined scope - picks up context, asks the right questions, delivers without needing tasks broken down Collaborative and low-friction in a squad setting Working Relationships Day-to-day: engineers and PMs within the team, with regular interaction with sister squads across the Subscriptions Mission. Frequent collaboration with Design, Content Design, and Legal, as well as data engineers, analysts, and ML engineers as experimentation work requires. Start/End: 2026-10-12 to 2027-04-11 Workplace: Sweden