Leszek Ciesielski
Software Engineer at Equal Experts
Poland
Summary
👤
Senior🎓
Top SchoolLeszek Ciesielski is a software engineer and architect with nearly two decades of experience designing and modernizing large-scale .NET backends and REST APIs. He has led migrations to modern .NET, built high-throughput messaging systems (including work on Kafka pipelines processing tens of millions of messages per hour), and delivered cloud-native deployments and CI/CD at enterprise scale. Comfortable owning end-to-end delivery, he also mentors teams, introduces TDD and DevOps practices, and has a track record of driving deploy frequency and stability improvements. His open-source contributions to the Mono project and tooling like NuKeeper show deep familiarity with the .NET build and package ecosystems beyond day-to-day engineering. Equally at home optimizing performance-critical paths (reducing memory or processing time by orders of magnitude) and bootstrapping startups, he blends pragmatic engineering with architectural foresight. Based in Poland, he’s a hands-on leader who thrives on untangling legacy systems and shipping reliable distributed services.
19 years of coding experience
18 years of employment as a software developer
MSc Software Engineering, MSc Software Engineering at Poznan University of Technology
Polish, English
Stackoverflow
32,320reputation
2.5mreached
257answers
48questions
sql
top-5%
pinvoke
top-5%
logging
top-5%
git
top-5%
android
top-5%
mime
top-5%
Github Skills (36)
nuget10
package-management10
msbuild10
net10
dotnet-new10
dotnet10
asp-net10
mono10
visual-studio10
dotnet-core10
csharp10
runtimes9
svn9
git9
xamarin-ios9
Programming languages (8)
Github contributions (5)
NuKeeperDotNet/NuKeeper
Jul 2017 - Sep 2021
Automagically update nuget packages in .NET projects
Role in this project:
Back-end Developer
Back-end DeveloperContributions:5 reviews, 169 commits, 338 PRs in 4 years 3 months
Contributions summary:Leszek focused on enhancing the NuKeeper's core functionality by modifying code related to package management for .NET projects. Their work included refactoring code for improved efficiency, matching package configurations, and adding support for reading and updating packages. They also contributed to test code, ensuring the reliability of the changes made to the project. The contributions are primarily related to package updates and integration, ensuring that NuKeeper is a robust tool.
dotnetnuget-packagesupdateautomationcsharp
mono/mono
Sep 2006 - Jun 2011
Mono open source ECMA CLI, C# and .NET implementation.
Role in this project:Back-end Developer
Back-end DeveloperContributions:40 commits in 4 years 10 months
Contributions summary:Leszek's commits primarily focus on implementing and refining the `Microsoft.Build.Construction` namespace within the Mono project, which is a .NET implementation. Their contributions include implementing project file loading, adding various project element types (ProjectRootElement, ProjectItemElement, etc.), and handling comments. These modifications suggest a focus on building the .NET build system, addressing missing functionality, and ensuring proper parsing and handling of project files within the Mono framework.
dotnetjitruntimemonoandroid
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