Marcus Klimstra
Founding Partner at XLRIT
Arnhem-Nijmegen Region Netherlands
Summary
👤
Senior🎓
Top SchoolMarcus Klimstra is a Technical Solution Lead with 13 years of experience building robust Java back-ends, compilers/parsers, and web technologies from the Netherlands. He combines deep expertise in Java, ANTLR, XML/XSLT/XPath and frameworks like Spring and Hibernate with hands-on experience improving core BPM engines such as Activiti and Flowable. As a founding partner at XLRIT and former software architect at CGI, he blends startup pragmatism with enterprise-grade architecture and a track record of stabilizing transaction and classloading code paths. Marcus has contributed concrete fixes and features to well-known open-source BPM projects—improving logging, exception handling and data handling—which reflects his focus on reliability and observability in distributed systems. He also brings entrepreneurial experience dating back to co-founding an online retail business, showing a long-standing habit of shipping complete technical solutions.
13 years of coding experience
16 years of employment as a software developer
Universiteit TwenteBachelor, Computer Science, Bachelor, Computer Science at Saxion University of Applied SciencesOSG Erasmus
Dutch
Github Skills (16)
processmaker10
javas10
transactionscope10
transaction10
workflow-engine10
transaction-manager10
activiti10
bpmn10
springframework10
java10
jta10
exception-handling9
jdbc9
mybatis-plus8
mybatis8
Programming languages (7)
Github contributions (5)
Activiti/Activiti
Nov 2012 - Feb 2016
Activiti is a light-weight workflow and Business Process Management (BPM) Platform targeted at business people, developers and system admins. Its core is a super-fast and rock-solid BPMN 2 process engine for Java. It's open-source and distributed under the Apache license. Activiti runs in any Java application, on a server, on a cluster or in the cloud. It integrates perfectly with Spring, it is extremely lightweight and based on simple concepts.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:51 commits, 3 PRs in 3 years 4 months
Contributions summary:Marcus primarily contributed to the backend of the Activiti BPM platform. They focused on improving the core engine, including logging deployments, refining expression exceptions, and fixing errors within variable handling (e.g., serializable types). The user also implemented features related to process instance and user linking and made improvements to classloading mechanisms. Additionally, the user made logging enhancements to deployment processing.
business-process-managementprocess-managementactivition-serverjava-application
scalar-labs/btm
Aug 2013 - Aug 2013
JTA Transaction Manager
Role in this project:Backend Developer
Backend DeveloperContributions:6 commits, 2 PRs, 4 comments in 14 days
Contributions summary:Marcus contributed to the `btm` project, a JTA Transaction Manager, by addressing minor fixes and improving its integration with Spring. Their work included modifying core classes related to JDBC resources and Spring integration, suggesting a focus on stability and compatibility. These changes were implemented across multiple files, including those related to data source management and Spring lifecycle integration. The user also corrected properties related to ResourceBean.
transactionjtatransaction-manager
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