Koen Vlaswinkel
Senior Software Engineer at GitHub
Eindhoven, North Brabant, Netherlands
Summary
🤩
Rockstar🎓
Top SchoolKoen Vlaswinkel is a Senior Software Engineer with 13 years of experience building backend systems, DevOps tooling, and security-focused code analysis. Based in Eindhoven and currently at GitHub, he has a track record of improving infrastructure-as-code (dnscontrol) and hardening code-scanning tools (CodeQL) by tackling nuanced issues like nested type handling and provider integrations. He combines practical Go and backend engineering chops with DevOps sensibilities—adding provider support, record-specific handling, and production-ready config and metrics controls. His background includes lead developer responsibilities at Drieam and technical writing for DigitalOcean, reflecting both leadership and clear technical communication. Notably, his open-source contributions improve both functionality and the reliability of security tooling used broadly across the developer ecosystem.
13 years of coding experience
10 years of employment as a software developer
Master's degree Computer Science and Engineering, Master's degree Computer Science and Engineering at Eindhoven University of TechnologyVWO; N&T + Biology + Technasium, VWO; N&T + Biology + Technasium at Pontes
English, Dutch
Github Skills (21)
github-advanced-security10
api-design10
microservices-application10
semmle-ql10
codeql10
go10
dns10
infrastructure-as-code10
microservices10
linode10
testing9
java9
workflow-engine9
csharp9
dotnet-core9
Programming languages (13)
Github contributions (5)
StackExchange/dnscontrol
Nov 2017 - Mar 2022
Infrastructure as code for DNS!
Role in this project:
Back-end Developer & DevOps Engineer
Back-end Developer & DevOps EngineerContributions:9 commits, 6 PRs, 7 comments in 4 years 5 months
Contributions summary:Koen contributed to the back-end functionality of the DNS control project by adding support for Linode DNS provider and implementing features like CAA record support and get-zones. The user also made improvements to the codebase, like allowing specific DNS record names (e.g., `_acme-challenge`). Their work demonstrates a focus on expanding provider integrations and enhancing the overall functionality of the infrastructure-as-code tool.
dnscontroldnsdslproviderssynchronize
github/codeql
Jan 2023 - Jul 2024
CodeQL: the libraries and queries that power security researchers around the world, as well as code scanning in GitHub Advanced Security
Role in this project:Security Engineer
Security EngineerContributions:16 reviews, 25 PRs, 36 pushes in 1 year 5 months
Contributions summary:Koen's commits primarily focus on improving the CodeQL query language for identifying security vulnerabilities. They addressed issues with the naming of external APIs, particularly concerning nested types in both Java and C#, ensuring accurate reporting in security analysis queries. The user also added tests to validate the correct handling of nested classes and generic types within the CodeQL framework, enhancing the reliability of the security analysis process. The contributions resulted in more accurate and robust code scanning capabilities.
github-advanced-securitysecurity-toolsgithub-security-labsecurity-researcherssecurity
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