Jan Zdrahal

Built internal platforms to streamline clinical-trial operations and keep clinical and research reference data consistent, governed, and trustworthy across the company. Delivered full-stack features across React frontends and FastAPI backend services, including service-layer and API design, data pipelines, and infrastructure. Implemented authorization capabilities with role-based restrictions on data-configuration writes. Operated day-to-day on Google Cloud Platform and Kubernetes (GKE) with services fronted by Pomerium and Envoy for zero-trust authentication. Owned CI/CD, deployments, observability, and production debugging across development and production environments using Codefresh and Argo, within a rigorous pull-request and code-review workflow that also uses Claude Code.

Worked on the next generation of Microsoft Teams, delivering UI and core-service features across Messaging, Chat, and Calling. Owned application performance efforts and supported correct GraphQL patterns across the complex Teams client. Contributed to repository package updates, unit testing, and end-to-end testing while collaborating in a large-scale enterprise React/GraphQL codebase.