Johann Wiedmeier

Java Developer

Building software for 37 million insurants in the context of the electronic patient health record system

• Gathering requirements, time estimations, project planning, coordinating with supplying teams
• Creating a profile concept to handle the needs of software product line engineering
• Feature development in a microservice environment
• DevOps, containerization and CI/CD into Kubernetes
• Generating PDF/A-1 documents with Quartz batch processing

Tech: Java 17, Spring, SOAP, REST, mTLS, Postgres, Liquibase, Quartz, Velocity, IText, JUnit, Testcontainers, Zonky, Maven, Bitbucket, Jenkins, Kubernetes, Docker, Jib, Helm, Kafka, Strimzi, AWS ECR, Gematik, SAP oscare

Software Engineer / Architect

• Built the subscription system for the Cookidoo platform
• Migrated millions of customers reliably to a new subscription platform
• Worked around missing idempotency of connected systems to stop double spending
• Improved the existing architecture for resiliency, performance and reliable messaging
• Re-implemented the backend for the integration of the new subscription platform
• Improved the release pipeline, (load-) testing and monitoring of the vertical (DevOps)
• Oncall with < 30min response time to quickly fix production issues

Tech: Java 11-21, Spring, Thymeleaf, Zuora, AWS Cloud, DynamoDB, Redis, SQS, SNS, S3, Aurora, Terraform, Kustomize, Gatling Load Testing, Gitlab, Kubernetes, Argo CD, AsciiDoc, Grafana, Go

Lead Software Engineer

Built a high-performance place reservation system for intercity transports

• Scaled to 10.000 req/s, with 95% below 30ms
• Developed major parts of the algorithm, REST APIs and persistence in the backend
• Developed frontends for reservations and train visualizations
• Load tested, profiled and removed bottlenecks for requirement verification and cost optimization
• Interviewed, onboarded and coached new team members

Tech: Java, Spring Boot, JUnit, Mockito, Mapstruct, Lombok, Swagger, JMeter, VisualVM, TypeScript, Angular, RxJS, AWS RDS PostgreSQL, Kubernetes, Pipeship, Openshift, Docker, GitLab, Jenkins, Jira

Software Engineer

Worked on Deutsche Telekom's CMS for Wi-Fi hotspots (>1 million LOC)

• Architected, developed, tested and deployed new features in the backend and frontend
• Moved the voucher system from Thymeleaf to REST services and TypeScript/Angular
• Increased team productivity by improving processes & tools
• Sped up the CI/CD pipeline by more than 50%
• Brought agile development methods and tools to the team (coding standards, code analysis, Scrum)

Tech: Java, Spring Boot, JUnit, Mockito, TypeScript, Angular, JavaScript, AngularJS, Thymeleaf, MySQL, Flyway, Docker, Gradle, Maven, GitLab, Jira, DevOps, SonarQube