Rafal Krzewski
Head Of Technology at Caltha - Krzewski, Mach, Potempski Sp. J.
Warsaw, Masovian Voivodeship, Poland
Summary
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SeniorRafal Krzewski is a seasoned Head of Technology and founder with over 22 years of experience designing and delivering server-side Java EE applications, large-scale content management systems, and database-backed publishing platforms. He blends hands-on engineering with technical leadership at Project CampSys and his long-running firm Caltha, applying Agile and Xtreme Programming practices to ship reliable systems. A pragmatic open-source contributor in the Scala ecosystem, he has helped maintain and modernize projects like Scalate, elastic4s, and doobie—work that involved adapting code to evolving Scala and library APIs and improving build and dependency management. Based in Warsaw, he pairs deep Java/J2EE expertise with contemporary functional Scala skills, making him equally comfortable optimizing classpaths and implementing complex aggregations for Elasticsearch. An understated strength is his ability to transition legacy enterprise systems toward modern, testable architectures while staying directly involved in core technical work.
22 years of coding experience
9 years of employment as a software developer
Polish, English, German
Stackoverflow
31reputation
190reached
0answers
1question
Github Skills (37)
circe10
cats-effect10
amazon-elasticsearch10
template-engine10
scala10
http-client10
elasticsearchquery10
fs10
aws-elasticsearch10
scala-compiler10
cat10
elasticsearch10
functional-programming10
eclipse10
functional-programming-language10
Programming languages (14)
Github contributions (5)
scalate/scalate
Aug 2012 - Jan 2018
Scalate is a Scala based template engine which supports HAML, Mustache and JSP, Erb and Velocity style syntaxes.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:55 commits, 3 PRs, 3 pushes in 5 years 5 months
Contributions summary:Rafal primarily focused on improving the Scala-based template engine, addressing compiler issues and API changes. Their work involved fixing "missing parameter type" errors and adjusting code to accommodate updates to the Scala compiler and OSGi APIs. They also optimized the build process by removing unnecessary dependencies and improving the class path management.
erbhamljspscalascalate
scala-ide/scala-ide
Dec 2012 - Aug 2017
Scala IDE for Eclipse
Role in this project:Software Engineer
Software EngineerContributions:21 commits, 11 PRs, 46 comments in 4 years 8 months
Contributions summary:Rafal primarily contributed to the Scala IDE for Eclipse project by addressing bugs and implementing improvements. Their work involved modifying core functionalities related to compiler bridge management, classpath handling, and breakpoint integration. They demonstrated expertise in optimizing build processes by moving compiler bridge caches and improving compatibility checks for compiler plugins. Further contributions included adjusting to IProgressMonitor handling and updating dependencies.
eclipsescala-ide
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