Alexander Reelsen
Software Engineer at Michael Weinig Aktiengesellschaft
Emsdetten, North Rhine-Westphalia, Germany
Summary
🤩
RockstarAlexander Reelsen is a pragmatic software engineer with 15 years of experience specializing in Java, concurrency, and scalable web architectures. He focuses on simplicity and reliable distributed systems, with deep hands-on work in search, analytics, and information retrieval—particularly contributing to Elasticsearch's Watcher, security, and monitoring components. An active open-source contributor, he has improved core JVM web frameworks like Javalin and Play by modernizing tests, tightening SSL behavior, and streamlining request handling. Based in Emsdetten, Germany, he combines a productivity-geek mindset with practical PaaS-era tooling to deliver maintainable, high-performance back-end code. Notably, his contributions span both feature enhancements and stability fixes across widely used projects, reflecting a balance of innovation and engineering discipline.
15 years of coding experience
Stackoverflow
1,774reputation
123kreached
117answers
2questions
elasticsearch
top-5%
Github Skills (36)
kotlin10
amazon-elasticsearch10
java10
watchers10
javas10
elasticsearchquery10
junit10
aws-elasticsearch10
jtest10
web-framework10
elasticsearch10
rest-api10
playframework10
elasticsearch-api10
ssl9
Programming languages (18)
Github contributions (5)
elastic/elasticsearch
Mar 2013 - Aug 2022
Free and Open Source, Distributed, RESTful Search Engine
Role in this project:
Back-end Developer
Back-end DeveloperContributions:3 reviews, 1664 commits, 562 PRs in 9 years 6 months
Contributions summary:Alexander contributed to the Elasticsearch project by implementing and fixing features related to the Watcher component. They added the ability to execute actions for each element in an array within the Watcher framework. Additionally, the user addressed bugs and improved error messages related to the CryptoService and HttpClient components, enhancing the system's stability and user experience. The contributions involved code modifications across various x-pack plugins, indicating a focus on the security and monitoring features of Elasticsearch.
restfulsearch-engineopensearchelasticsearchjava
javalin/javalin
May 2021 - Feb 2022
A simple and modern Java and Kotlin web framework
Role in this project:Back-end Developer
Back-end DeveloperContributions:3 reviews, 7 commits, 6 PRs in 9 months
Contributions summary:Alexander primarily contributed to the Javalin web framework by updating dependencies, adding new features, and refactoring existing code. Their work includes updating the JTE rendering library, adding a helper class for header configuration, and optimizing the handling of form and query parameters. The user also migrated tests to JUnit 5 and addressed context-related improvements within the framework.
frameworkjavalinkotlinjettyservlet
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.