LFAbout Lars
I have 20+ years of experience in software development, mainly working with Java (Oracle Certified), Spring Boot, and web applications. Over the years, I’ve built, improved, and maintained software for logistics, transportation, eCommerce, AI/NLP, and sports marketing.
My work includes developing web applications, enhancing existing systems, and setting up build pipelines using GitHub, GitLab, or Jenkins. I have a lot of experience with modern containerization and virtual server platforms like Docker dev environments and smaller Docker Swarm launchpads. I am also comfortable configuring and maintaining traditional server setups that haven’t yet been modernised.
Most recently, I tackled challenges in a public transportation system, where I developed a strong interest in observability. Working with OpenTelemetry, Micrometer, Prometheus, and Elasticsearch, I saw firsthand how monitoring and logging can make complex systems more reliable and easier to maintain.
"Microservices with Spring Boot" is often presented as the answer to any software problem, but successful applications are built around business needs and profitability. Most existing software can’t simply be replaced from scratch. Real progress comes from paying attention to details, preserving what works, and putting in the effort to improve.
Please check out my CV to read more about me.
My company ecruos GmbH & Co. KG (ecruos.de) is registered in Germany and I do not support any false self-employment working models in Germany.
German
Native or bilingual
English
Fluent
Portuguese
Fluent
Can work on-site
Cologne (up to 50km), Hamburg (up to 50km), Frankfurt am Main (up to 50km)
Experience
- WirefunkLead Software EngineerDIGITAL AND ITNovember 2024 - Today (1 year and 8 months)Cologne, GermanyWirefunk is a lightweight observability stack for web, backend, and API-based systems. It consolidates high-volume log aggregation into a structured data store with a simple UI for service monitoring and alerting, focusing on practical insights without unnecessary complexity.
- Developed a prototype to enhance API observability using Spring Boot, Micrometer, and OpenTelemetry, serving as a benchmarking tool for external REST APIs.
- Implemented modern GitHub pipelines to build the application as an optional GraalVM native image, packaged in a Docker container image using Buildpacks within the Spring Boot plugin.
- Additionally Github Dependabot was configured to keep the apps dependencies updated daily. Security updates were applied immediately. Openrewrite is used as well to keep some best practices on form and style of Classes, configuration files and code structure itself
- Cubic Transportation SystemsSoftware Engineer, DevOps SupportTECHOctober 2023 - September 2024 (11 months)Hamburg, GermanyCubic develops cloud-based transportation software with a vast range of functionalities, primarily generating QR codes for digital tickets used in metro, bus, and train services. Beyond ticket sales, the company provides CRM, identity management, accounting, invoicing, and other transportation-focused solutions. Its London-based branch powers Transport for London and parts of Dublin’s NTA.
- During a critical phase of a key project, the entire core team left for unknown reasons to me. I jumped in as an external all-round specialist to keep their main Java application operational
- Beyond technical challenges, I coordinated daily with clients and partners promoting a mobile app that provided pay-as-you-go tickets, real-time schedules for buses, metros, and trains, and other services, that are already in use by thousands of commuters and fully reliant on Cubic's infrastructure.
- Filtering issues and making smart decisions about what had to be patched, refactored or updated first. Reviewing and simplifying over-engineered parts of the application. Discuss and define tasks according to team-skills.
- Took the initiative to refactor a large GitHub repository structure, creating fast CI-pipelines and reducing build times from 20minutes to 3minutes. Simply by working hard to understand the Software itself and its build tool configuration. CD was a topic I pushed as well, it was too challenging and too much as a step for me, the team and the company
- Deployment cycle was more or less every 3 months by the older team, which we eventually reduced to every 2-3 weeks
- Due to a lack of log-monitoring, I introduced an improvised possibility for log-collection/log-analysis with a modified ELK-Docker solution. FluentD was used instead of Logstash due to better resource efficiency
- Led efforts to enhance Observability with Micrometer and Datadog. Micrometer had to be configured manually due to lack of native Apache Karaf support.
- TECHCONNECT LOGGISenior Software EngineerTECHNovember 2021 - September 2022 (10 months)Lisbon, PortugalI joined Loggi, a Brazilian logistics unicorn valued at over $1 billion after its Series F funding, to support finance automation for large-scale B2B delivery operations.
- Helped streamline finance-related data workflows, integrating them into an SAP-based BI system to reduce data loss and improve efficiency.
- Analyzed and refactored legacy code (Python/Kotlin), collaborated on workflow optimizations, and debugged existing solutions.
- Introduced an adapted sprint model and task planning based on flavoured SCRUM principles, especially planning and reviews.
- Contributed to the technical foundation for Loggi's planned 2023 US IPO.
Recommendations
Be the first to recommend Lars
Help this freelancer shine by sharing your experience working together.
These freelancer profiles also match your criteria
Agatha Frydrych
Backend Java Software Engineer
4.7
(3)
2
Baptiste Duhen
Fullstack developer
4.6
(4)
5
Amed Hamou
Senior Lead Developer
4
(2)
7
Audrey Champion
Web developer
4.3
(3)
4
Education
- Bachelor of ScienceUniversity of Applied Sciences2013Medical Computer Science
Certifications
- Java ProgrammerOracle Certified Associate2022