07/2022 — 06/2026
Full Stack Developer
The Key Technology GmbH · Berlin
- Owned features end-to-end as primary developer for six web applications and two React Native apps in a two-developer team, from clarifying requirements with the client through implementation, testing and release.
- Developed and maintained React Native applications, updated plugins, and independently managed Android app releases through Google Play Console.
- Built bidirectional Salesforce synchronization for users, modules and learning results across gRPC-connected Scala backend services, covering create, update and delete flows, including a cross-platform uniqueness check that prevented duplicate module identifiers.
- Developed integration tests across numerous Scala/Play backend services using ScalaTest, Guice and MongoDB, covering CRUD operations, business logic and error handling.
- Investigated and resolved certificate errors in regulated medical education, tracing root causes through historical course and submission data, correcting affected records and regenerating certificates.
- Built permissions, progression and certification workflows for a learning platform with 50,000+ users and ~500 courses, including eligibility rules, blocked-course states and expiring-certificate views.
- Implemented Figma designs for a separate platform with ~500 courses, including a rebuilt production dashboard; reduced its load time from ~7 s to 2 s by optimizing MongoDB indexes and adding progressive skeleton states.
- Created assessment reporting for randomized question sets, calculating answer exposure, correct responses and the most frequently selected wrong answers from stored MongoDB data.