Michael König
Software Developer
Experience
Nov 2024 - Feb 2024
-1 years -8 monthsSoftware Developer
Atruvia AG
- The EGP (Enterprise Banking Control Platform) is a comprehensive banking control solution that unifies various business requirements such as accounting, regulatory reporting, controlling, and risk management in a single system. The EGP framework is a collection of cross-cutting libraries and services used across all bounded contexts of the platform.
- Software development: Enhancing framework components and services. Primarily with Spring Boot (90%) and some Python (10%).
- Executed migration from Java 17->21 and Spring Boot 3.2->3.4 in about 80 library and service repositories (adjusting Maven POMs, Dockerfiles, Jenkins pipelines, source code migration, test evolution).
- Developed unit and integration tests with JUnit and JGiven.
- Performed and analyzed performance measurements using Dynatrace.
- Enhanced multi-stage CI/CD pipelines (unit tests, security analyses, Docker build, Harbor deployment, etc.).
- Tech stack: Java (90%), Python (10%), Spring Boot, JPA/Hibernate, JGiven, OpenAPI, Camunda 7, Podman, OpenShift/Kubernetes, Oracle DB, SonarQube, Dynatrace, Jenkins, Harbor, Bitbucket, Jira, Confluence.
May 2024 - Present
1 year 3 monthsArchitect and Full-Stack Developer
Klareau GmbH
- In this project, we built a modern platform for calculating and simulating complex treatment processes in wastewater plants (planning and operation). The application works online and offline (office PC, iPad on site without internet). In a small team of three, my role was to ensure a robust, scalable software architecture and follow modern development methods (Scrum, CI/CD, cloud-native, DDD, TDD, shift-left, etc.).
- Because the team is small, I handled a variety of tasks:
- Gathering and documenting functional and non-functional requirements and quality goals.
- Designing and documenting a flexible, high-performance software architecture (Arc42, UML, BPMN).
- Building robust ("self-healing") and cost-efficient ("auto-scaling") cloud infrastructures (IaC with Terraform + GitLab CI).
- Implementing cloud monitoring and alerting.
- DevOps work on CI/CD pipelines with GitLab, including multiple test stages (shift-left approach), static code quality and security scans (code and container level).
- Defining REST APIs (contract-first with OpenAPI).
- Developing microservices in Kotlin (Spring Boot, MongoDB).
- Also partly contributing to the Angular frontend.
- Tech stack: AWS EKS + Fargate, MongoDB, CloudFront, CloudWatch, Elasticsearch, Kibana, Kotlin, Spring Boot, Angular/TypeScript, Helm, Terraform, GitLab CI/CD.
Jun 2023 - Apr 2024
11 monthsArchitect and Full-Stack Developer
Atruvia AG
- As part of an innovative platform project at Atruvia AG (500+ staff), I was key in developing and implementing a cloud service that lets Atruvia customers host their own services within a cloud infrastructure. I focused on designing and building a marketplace as a central shop system for ordering and configuring cloud services.
- Main tasks and responsibilities:
- Software development: Building microservices in Java, Kotlin, TypeScript, and Python. Mainly Spring Boot (70%) and Angular (30%). On the backend I implemented REST controllers, services, entities, and repositories (using DDD principles). I focused on performance tuning with efficient caching using Redis and MongoDB, and also used Postgres. I integrated with an SSO system via OAuth2/OpenID. On the frontend, I worked on existing and new Angular components and services, focusing on TypeScript and HTML, less on CSS.
- Architecture management & modeling: Optimizing and documenting system architecture and modeling interfaces to our frontend and other microservices. I documented the architecture in the proprietary Atruvia DocIT4U framework. I initiated and implemented the shift from code-first to contract-first with OpenAPI, so both backend and frontend now use generated stubs. This keeps the interface stable and prevents unexpected frontend issues.
- Testing: Besides unit and integration tests in Java and Kotlin with JUnit and EasyMock, I implemented load and performance tests with JMeter and integrated them into the CI pipeline. On the frontend, I wrote tests with Jasmine and end-to-end tests with Cypress, making them mandatory in the CI/CD pipeline for every merge request.
- DevSecOps: Enhancing multi-stage CI/CD pipelines (security analyses, E2E tests with Cypress, load tests with JMeter, Docker build, Harbor deployment, etc.).
- Technologies: Java, Kotlin, TypeScript, Python, Spring Boot, JPA/Hibernate, Angular, OpenAPI, Docker, OpenShift/Kubernetes, Helm, GitLab, Redis, Postgres, MongoDB, Grafana, Cypress, JMeter, DDD, TDD, Scrum, SAFe.
Sep 2020 - May 2023
2 years 9 monthsInterim CTO, Solution Architect and Developer
FI Freiberg Institut GmbH
- The prototype was a monolithic system hosted on the developer’s PC that needed functional expansion for commercial use and cloud availability. I became Interim CTO and Software Architect.
- Under my leadership, we split the monolith into microservices, added major features, designed OpenAPI interfaces (contract-first/code generated), set up AWS cloud infrastructure with Terraform, applied cloud security (least privilege), built CI/CD pipelines, autoscaling, monitoring, and alerting. Customers, management, and the DevOps team are all satisfied: the app is reliable and performant even during deployments or peak loads, balancing cost efficiency, performance, and high availability. AWS certifies the system as Well-Architected.
- The software is a simulation and multi-objective optimization tool for complex energy industry questions.
- Tech: Backend services mostly Spring Boot/Kotlin. The optimization core is a genetic algorithm based on jMetal. Frontend uses Vue.js/TypeScript. Infrastructure with Terraform.
- My tasks:
- Code and architecture reviews of the prototype and ongoing.
- Due diligence.
- Designing target cloud-native architecture.
- Selecting a cloud or hosting provider.
- Establishing a development process and agile model with toolchain.
- Team leadership.
- Risk management.
- Refactoring the prototype into microservices.
- Building and maintaining CI/CD with GitLab, deploying Docker containers to AWS (Beanstalk then Kubernetes).
- Designing architecture to meet user and performance needs.
- Defining the test pyramid (unit, integration, end-to-end, performance tests).
- Implementing features for user management and billing.
- Adding event-driven architecture with Kafka.
- Implementing logging and monitoring (ELK/Kibana, Grafana, AWS X-Ray, CloudWatch).
- Using many AWS services.
- Team size: 8 developers/DevOps + 3 (PO/analyst/testers).
- Skills: Cloud-native architecture, microservices, Kotlin, Java, JPA, REST, messaging, OAuth2/OpenID, UML, DDD, test-driven design/shift-left, Scrum, OKR.
- Tools: Spring Boot, GitLab, AWS (ECS, EC2, Beanstalk, Lambda, Route53, ALB, S3, SQS/SNS, CloudWatch, RDS, VPN, MSK,…), Kafka, Vue.js, Grafana, jMetal, Postgres, ClickUp.
Oct 2017 - May 2020
2 years 8 monthsHanover, Germany
Software Architect / Developer
TUI Infotec GmbH
- Replaced a third-party booking component for flight extras (seats, baggage, meals, etc.) with a highly available, self-healing microservice system. Integrated many external and heterogeneous interfaces (usually airline carriers or internal systems). Services run as Docker containers in an AWS cloud cluster.
- Coordinated interfaces with external partners (airline booking systems) and other teams.
- Architected and documented the microservice system.
- Advised on development and deployment processes (CI/CD).
- Set architecture guidelines and performed code reviews.
- Implemented core libraries and microservices.
- Ensured quality (coding conventions, test coverage, documentation).
Jun 2015 - Sep 2017
2 years 4 monthsStuttgart, Germany
Software Architect / Developer
T-Systems International GmbH
- Project goal: Migrate and break down a complex monolithic JEE application on WSO2 (AS, ESB, Identity Server, Governance Registry) into standalone Spring Boot apps (microservice architecture) and extend functionality.
- Coordinated, specified, and documented microservices (REST API, MQTT, JMS).
- Developed core libraries and microservices.
- Defined architecture guidelines and performed code reviews.
- Coordinated with other teams, central architecture, and client reps.
- Ensured quality (coding conventions, test coverage, documentation).
Oct 2014 - Apr 2015
7 monthsDresden, Germany
Software Architect / Performance Analyst
T-Systems Multimedia Solutions GmbH
- Project: Carus Consilium Sachsen (telemedicine)
- Performance and memory analysis/tuning.
- Finding and fixing scaling and threading issues.
- Code and architecture reviews.
- Implementing core classes and framework code.
- Architecting cross-cutting concerns like auth, performance, caching, logging, transaction and exception handling.
Jul 2013 - Aug 2013
2 monthsNuremberg, Germany
Consultant / Software Architect
ING-DiBa
- Project: Code and architecture review of various internal banking applications.
- Reviewed code and architecture of ING-DiBa software components.
- Consulting on security and performance aspects.
Sep 2010 - Sep 2014
4 years 1 monthDresden, Germany
Solution Architect
T-Systems Multimedia Solutions GmbH
- Project: De-Mail (large project >100 staff, English-speaking)
- Analyzing business and technical requirements, effort estimates.
- Modeling business processes (BPMN, UML) and use cases (UML and text).
- Defining target architecture and needed components.
- Deriving entities and data model.
- Aligning interfaces and system boundaries.
- Deciding on frameworks, APIs, and tools.
- Creating functional and technical specs.
- Planning tasks and directing architects and developers.
- Reviewing architecture and code.
- Coaching developers.
Nov 2008 - Aug 2010
1 year 10 monthsBerlin, Germany
Software Architect / Developer
Lufthansa Systems Berlin GmbH
- Project: Revenue Management
- Architected and developed a proprietary ORM framework (inspired by JPA, JDO, Hibernate, Rails ActiveRecord).
- Implemented various services (business layer and domain model layer in SOA).
- Performed performance and stability analysis, identified and fixed scaling and multithreading issues.
Aug 2008 - Oct 2008
3 monthsDarmstadt, Germany
Java Developer / Analyst
General Electric Energy GmbH
- Project: Visualization of geo-data (GIS), order and cooperation management
- Java development.
- Performance, stability, and code quality analysis.
- Created JUnit and Cactus tests.
- JBoss configuration, trimming, and tuning (cluster architecture).
Technical Project Lead / Software Architect / Developer
ITEC GmbH
- Project: Heat pump sizing program 'WDim'
- Simulation software for sizing heat pump systems for single-family and multi-family homes, including modules for cost-benefit analysis, alternative heat sources, and heat demand calculations by different methods.
- Created software architecture.
- Implemented desktop application.
- Technical project lead.
Dresden, Germany
Technical Project Lead / Software Architect
T-Systems Multimedia Solutions GmbH
- Project: Human Resources Management, Deutsche Telekom job board (international, fully localized including Austria, Switzerland, South Africa, Spain, etc.)
- Technical project lead.
- Analyzed requirements and created functional and technical specs.
- Modeled workflows (BPM).
- Built application prototype.
- Defined software architecture.
- Supported development and consulting.
- Developed workflow engine and complex roles/permissions concept.
- Ensured quality.
- Coached and supported team members.
Dresden, Germany
Technical Project Lead / Software Architect
T-Systems Multimedia Solutions GmbH
- Project: Telekom HR portal
- Integration of legacy applications and new components into an SOA (OSGi component architecture; frontend as rich internet application with web desktop).
- Created technical specs.
- Prototyping / proof of concept.
- Software architecture.
- Technical consulting.
- Technical project lead.
- Reviewed architecture and code.
- Coached developers.
Summary
As an analytical problem solver, I enjoy using creative solutions and continuously furthering my education to broaden and deepen my knowledge. My core competencies lie in solution and software architecture as well as backend development and DevOps. With many years of experience and curiosity, I balance effectiveness and high quality standards with healthy pragmatism and efficiency.
Languages
German
NativeEnglish
Advanced Certifications & licenses
AWS Certified Developer – Associate (DVA)
AWS
AWS Certified Solutions Architect – Associate (SAA)
AWS
iSAQB Certified Professional for Software Architecture, Advanced (CPSA-A)
iSAQB
SpringSource Certified Enterprise Integration Specialist (SCEIS)
SpringSource
OMG Certified Expert in Business Process Management - Fundamental (OCEB-F)
OMG
OMG Certified UML Professional – Intermediate (OCUP-I)
OMG
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