• Design and evolve data models and service contracts that scale cleanly and remain stable over time • Build reliable, observable backend services with clear SLOs; instrument, measure, and iterate to improve latency and uptime • Drive performance and correctness across critical flows; prevent regressions with solid testing and reviews. • Collaborate with cross‑functional partners to translate requirements into platform capabilities and ship them end‑to‑end. • Operate services in production; participate in on‑call; learn from incidents to strengthen the platform. • Communicate tradeoffs, risks, and milestones clearly; remove blockers and keep work moving.