Rainer B.
Senior Developer
Experience
Feb 2025 - Jul 2025
6 monthsSenior Developer
RWE Trading
- Role in team “Data Tycoons”
- Development of custom microservices based on Spring Boot framework
- Technologies: PostgresQL, ActiveMQ, Kafka, S3, Spark, Parquet/Avro file I/O
- Replaced Scala-based microservices with implementations on Spring Boot 3/Java 21
- DevOps responsibility for managing services and infrastructures
- Skillset: Java 8/11/17/21, Scala 2/Akka, Spring Boot, PostgresQL, Elasticsearch, Apache Kafka, ActiveMQ, Maven, JUnit, Testcontainers, AWS, Azure DevOps, HashiCorp Terraform, JIRA/Confluence
Jul 2024 - Dec 2024
6 monthsSenior Developer
Energy trading company
- Reimplemented Scala 2-based microservices as Spring Boot services
- Senior DevOps role working closely with internal customers
- Configured and managed AWS runtime environment
Jul 2023 - Mar 2025
1 year 9 monthsSenior Developer
Hagebau IT
- Team “NEONDI Data Pool”
- Direct report to lead software architect; supporting role for project lead
- Developed microservices based on Spring Boot 3/Apache Camel
- Infrastructures: MongoDB, Elasticsearch, Kafka
- Senior DevOps engineer: maintained GitLab build pipeline and service deployment on HashiCorp Nomad cloud
Jul 2021 - Jul 2024
3 years 1 monthSenior Lead Developer
Porsche AG
- Team “Open Source Office”; direct report to lead software architect; supporting project lead
- Senior DevOps role; collaborated with internal customers
- Implemented custom extensions and open-source improvements to Open Source Review Toolkit (ORT)
- Integrated and operated OAuth2/OIDC infrastructure with Keycloak
- Lead developer for custom microservice mesh for FOSS compliance workflow based on Spring Boot 2 and 3
- Configured and managed AWS runtime environment
Jul 2021 - Mar 2023
1 year 9 monthsSenior Lead Developer
Airplus
- Team “External Authentication Services”; supported project lead
- Senior development role; collaborated with internal customers
- Integrated with company-wide OAuth2/OIDC infrastructure
- Extended customer-facing OAuth2/OIDC system (RedHat SSO/Keycloak) with custom modules; operation support
- Development lead on custom microservices for authentication, authorization, CRM integration based on Spring Boot 2 and 3
- DevOps role for microservices in Microsoft Azure environment
Nov 2019 - Jun 2021
1 year 8 monthsSenior Development Lead
Signal Iduna
- Area of electronic document archiving; direct report to project lead
- Collaborated with internal customers; technical lead on internal development team
- Created and evaluated concepts, processes, architecture, implementations for custom solutions
- Designed and implemented microservice architecture for long-term document archiving
- Integrated with company-wide OAuth2/OIDC infrastructure
- Designed microservice solution for evaluating customer PDFs against PDF/A requirements
- Established DevOps approach for development and operation of customer-specific solutions
- Built custom microservices using Java 11+, Spring Framework/Boot, SDA-framework (Dropwizard, CDI, Hibernate, MongoDB, Apache Kafka), OpenShift/Kubernetes/S3
Oct 2018 - Oct 2019
1 year 1 monthSenior Consultant
ITZBund
- Supported system architecture for register-based procedure implementation
- Direct report to project lead; senior troubleshooting role
- Developed concepts and strategies; proof-of-concept on-premises private cloud infrastructure
Sep 2018 - Sep 2018
1 monthDeveloper
Kühne+Nagel (Airfreight logistics)
- Developed customer-specific airfreight logistics solution
- Technologies: Java 8/Java EE 7, Spring Framework/Security/Boot/Data/Integration/Batch/Hateoas/WS
- Mobile and desktop dialogs with GWT 2.6.x and HTML5
- Integrated with enterprise backoffice via SOA, RESTful and messaging services
Jul 2018 - Aug 2018
2 monthsSenior Consultant
ITZBund
- Supported system architecture for register-based procedure
- Direct report to project lead
- Detection, analysis, troubleshooting in application and infrastructure
- Senior role in containerization and Docker-based deployment
Apr 2018 - Aug 2018
5 monthsDeveloper
Vodafone Group
- Designed and implemented backend scheduler solution for ReST service calls
- Managed millions of stored ReST requests; handled up to 100 parallel calls/sec
- Technologies: Spring Boot, Akka messaging/clustering, Quartz Scheduler, Infinispan data grid, Docker, Kubernetes
Mar 2017 - Apr 2018
1 year 2 monthsSolution Architect & Lead Developer
Hermes Deutschland
- Designed and implemented microservice-based backend/middleware for private shipping orders
- Broke down monolith into microservice mesh
- Technologies: Spring Boot/Security/Data JPA/Cloud, Akka actor framework, Infinispan data grid, Apache Kafka
- Upgraded microservices from Spring Boot 1/Spring 4 to Spring Boot 2/Spring 5
- Deployed with Docker, Kubernetes, OpenShift, OpenStack on Open Telekom Cloud, Telekom AppAgile
- Implemented CI/CD pipeline with Jenkins; defined software delivery and DevOps processes
- Migrated SVN to Git; set up monitoring with Prometheus/Grafana; implemented custom metrics
- Defined microservice ground rules; introduced ad-hoc monitoring on OpenShift/Kafka
Jan 2017 - Mar 2017
3 monthsDeveloper
Deutsche Bahn AG
- Designed and implemented custom logging solution for ruggedized Android tablets exchange
- Technologies: JBoss WildFly 10/RedHat EAP 7, JEE 7, Apache Camel, Lucene, Spring Framework
- Microservice-based logging: technical, functional, audit logs; integrated search engine for indices in RDBMS
Nov 2016 - Dec 2016
2 monthsSenior Consultant
Mobilcom / Debitel
- Supported design/architecture for internal API to document archive and print services
- Technologies: RESTful/microservice design, Apigee Edge Gateway
- Domain-driven design principles; implemented RESTful webservice for automatic Apigee proxy configs and online docs using Spring Framework and Akka
Oct 2016 - Oct 2016
1 monthDeveloper
Vodafone Group Services
- Developed API proxy translating between SOAP and RESTful webservices
- Technologies: Java 8, Spring Framework/Boot/Security/WS/Cloud, SOAP, REST
- Agile (Kanban) process
Jan 2016 - Dec 2016
1 yearDeveloper
Kühne+Nagel (Airfreight logistics)
- Developed customer-specific airfreight logistics solution
- Technologies: Java 8/Java EE 7, Spring Framework/Security/Boot/Data/Integration/Batch/Hateoas/WS
- Mobile/desktop dialogs with GWT 2.6.x, HTML5; test env with programmable mock services
- On-demand PDF creation with Apache FOP/XSL-FO; virtualization with VirtualBox, Docker
- Code maintenance; integrated with Elasticsearch, Logstash; Oracle DB design/migration; replaced Oracle AQ with RabbitMQ
- Agile (Scrum/Kanban)
Aug 2015 - Nov 2015
4 monthsDeveloper
Hydro Aluminium Rolled Products
- Developed customer-specific storehouse management solution
- Technologies: Java 7/Java EE 7 (JSF, EJB, JPA, JMS), WildFly 8.2, HTML5 with PrimeFaces/Bootstrap
- Integrated with production management system; development, module/integration testing, support to production
Jan 2011 - Dec 2015
5 yearsTechnical Lead & Lead Architect
Vodafone Group Services
- Led APIX (API exposure gateway) infrastructure for controlled access to back-office services
- Supported projects: Message+, Vodafone Start, Backup+, Vodafone Deutschland self-care portal
- Responsibilities: REST API design, NoSQL (Cassandra) data storage/schema design (CQL2/CQL3), operations support, ESB integration (SOAP to REST/HATEOAS)
- Prototyped IoT services (MQTT), distributed log collection with Apache Kafka
- Technologies: JBoss/WildFly, Spring Framework/Boot, Akka/Java, Apache Kafka
Jan 2008 - Dec 2011
4 yearsTeam Lead
Vodafone Group Services
- Designed and implemented chat bridging service between Vodafone 360 and GoogleTalk/Yahoo/MSN
- Led scalable reporting solution on Apache Hadoop: 200 GB/day DB content; 1 TB/month mailserver logs
- Responsibilities: architecture and implementation lead, Hadoop data storage and reporting
Jan 2006 - Dec 2008
3 yearsPrototype Developer
Vodafone Group Services
- Developed “live@home” prototype (Award: Mobile World Congress 2007) and Group SMS solution “Group Comms”
- Planned, set up, operated dev/test environments integrated with Vodafone SS7 core
- Responsibilities: architecture and development lead, Telco voice/data network integration
Jan 2003 - Dec 2006
4 yearsDeveloper
Vodafone Germany
- JEE development for Vodafone Germany customer self-service portal
- Designed and implemented MMS-based product “D2 Easy Reply”
- Provided design, architecture, implementation consultancy and quality assurance
Jan 1999 - Dec 2003
5 yearsPlatform Engineer
Vodafone Germany
- Planned, set up, operated server and application server platforms for Vodafone Germany customer self-service portal (2nd/3rd generation)
Jan 1997 - Dec 1999
3 yearsIT Manager
- Planned, set up, operated company data network
- Designed and implemented customer-specific software for TV and advertising
- Provided IT first/second-level support; temporary IT department manager
Jan 1992 - Dec 1996
5 yearsManaging Director, IT Division
GTN – Telecommunications and Network Services Company
- Planned, set up, operated first private nationwide data network with international Internet connectivity
- Organized and managed first/second-level support department
Jan 1988 - Dec 1993
6 yearsConsultant
GTT – Telephone and Telecommunications Consulting Company
- Planned, set up, operated company data network
- Designed and implemented customer-specific telecommunication services
- Consulted on planning, setup, operation of telephony and data network solutions
Jan 1983 - Dec 1988
6 yearsFreelancing Software Developer
- Designed and implemented video games on ZX Spectrum, Sinclair QL, Commodore Amiga
- Developed hardware drivers for sound on Sinclair QL; hard disk drivers for Commodore Amiga
Languages
German
NativeEnglish
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