Mathias Jessen
Threat Detection Engineer
Amsterdam, North Holland, Netherlands
Summary
🤩
RockstarMathias Jessen is a Threat Detection Engineer with 11 years of experience building pragmatic security and Windows platform solutions at scale, currently focusing on IAM, UEBA and automated response at Booking.com. He combines deep Microsoft stack expertise—PowerShell, Active Directory, Windows Server—and practical sysadmin roots to troubleshoot elusive incidents and deliver sustainable, business-aligned fixes. A strong believer that people and economics matter as much as tech, he bridges end users, developers and managers to produce maintainable, real-world systems. An active open-source contributor, he’s improved PowerShell itself and hardening-focused projects like dbatools, removing legacy dependencies and adding tests to boost reliability and cross-platform compatibility.
11 years of coding experience
9 years of employment as a software developer
Stackoverflow
166,625reputation
11.1mreached
4,516answers
9questions
azure
top-5%
regex
top-5%
aes
top-5%
recursion
top-5%
symlink
top-5%
timestamp
top-5%
Github Skills (68)
windows10
databases10
asp-net10
dotnet10
active-directory10
powershell10
csv10
database10
json10
net10
sql-server10
microsoft-sql-server10
csharp10
mssqlserver10
mssql10
Programming languages (7)
Github contributions (5)
PowerShell/PowerShell
Aug 2017 - May 2022
PowerShell for every system!
Role in this project:
Back-end Developer
Back-end DeveloperContributions:23 reviews, 12 commits, 34 PRs in 4 years 10 months
Contributions summary:Mathias contributed to the PowerShell project by addressing bugs and implementing new features related to core functionalities. They fixed an issue in `Start-Trace` related to escaping file paths and added a char range overload to the DotDot operator, expanding the language's capabilities. Furthermore, the user provided support for lambda expressions within the `-replace` operator, enhancing the string manipulation features. They also addressed several other bugs and added functionality.
windowspowershelllinuxcommand-linemacos
dataplat/dbatools
Dec 2017 - Nov 2018
🚀 SQL Server automation and instance migrations have never been safer, faster or freer
Role in this project:Database Engineer / Database Administrator
Database Engineer / Database AdministratorContributions:7 commits, 5 PRs, 5 comments in 10 months
Contributions summary:Mathias's contributions primarily revolve around maintaining and improving the dbatools PowerShell module. They refactored code for better readability, removing code duplication and ensuring consistent coding style across multiple files. The user also removed dependencies like `WindowsBase` and deprecated constructors, which indicates a focus on optimizing the project for broader compatibility and maintainability, and removing of obsolete code. Furthermore, the user has written tests to improve the reliability of the code.
sqlserverbackupsaferserver-automationsql-server
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