Senior Backend Engineer - Java/Kotlin (x/f/m)

Senior Backend Engineer - Java/Kotlin (x/f/m) Set a new pulse for healthcare!We are looking for a Senior Backend Engineer to join the IAM (Identity and Access Management) team in Platform Services Tech. Your mission will be to secure and scale the authentication capabilities that millions of Doctolib users rely on every day. You will drive the most impactful phases of a critical, multi-year migration to a self-hosted, Keycloak-based identity provider — a project at the intersection of platform engineering, security, and cross-team impact. Working in the tech team at Doctolib means building innovative products and features to improve the daily lives of care teams and patients. What you'll doYour responsibilities include but are not limited to: Lead the next phases of the multi-year authentication migration to a self-hosted, Keycloak-based identity provider — completing token-based sign-in for Doctolib Pro apps and making the identity provider the single source of truth for user data Own the reliability of high-traffic authentication systems end-to-end: monitoring, alerting, SLOs, incident resolution, post-mortems, and safe rollout practices (feature flags, canary releases, zero-downtime migrations) Drive cross-team delivery independently: produce design documents and decision memos, build alignment across dependent teams, and make trade-offs explicit Collaborate closely with the Product Security team on security-sensitive architecture decisions and changes Contribute to fron