I’m a Senior Full Stack Software Engineer with 20+ years of experience designing, building, and operating large-scale production systems across web, cloud, and distributed environments. I’m passionate about engineering quality, performance optimization, and pragmatic architectures. I regularly use AI-assisted tools like GitHub Copilot and ChatGPT to accelerate development, debug faster, and prototype new solutions, while mentoring teammates and collaborating with product stakeholders.…

Sebastian Birlet

I’m a Senior Full Stack Software Engineer with 20+ years of experience designing, building, and operating large-scale production systems across web, cloud, and distributed environments. I’m passionate about engineering quality, performance optimization, and pragmatic architectures. I regularly use AI-assisted tools like GitHub Copilot and ChatGPT to accelerate development, debug faster, and prototype new solutions, while mentoring teammates and collaborating with product stakeholders.…

Available to hire

I’m a Senior Full Stack Software Engineer with 20+ years of experience designing, building, and operating large-scale production systems across web, cloud, and distributed environments.

I’m passionate about engineering quality, performance optimization, and pragmatic architectures. I regularly use AI-assisted tools like GitHub Copilot and ChatGPT to accelerate development, debug faster, and prototype new solutions, while mentoring teammates and collaborating with product stakeholders.

See more

Skills

Experience Level

C#
Expert
.NET
Expert
JavaScript
Expert
ASP.NET
Expert
React JS
Expert
HTML5
Expert
Node.js
Expert
SQL
Expert
ChatGPT
Expert
PHP
Expert
MySQL
Expert
GitHub Copilot
Expert
Oracle
Expert
Prompt Engineering
Expert
jQuery
Expert
TypeScript
Expert
Xamarin
Expert
XML
Expert
Android
Expert
Kubernetes
Expert
iOS
Expert
Docker
Expert
CSS
Expert
Azure
Expert
AWS
Expert
UI
Expert
Web Design
Expert
AI Data Labelling
Intermediate
See more

Language

English
Fluent
Polish
Fluent
Dutch
Beginner
French
Beginner
Japanese
Beginner

Work Experience

Senior Software Engineer at Soundnet Ltd
February 1, 2014 - November 1, 2025
Delivered end-to-end commercial systems used across nationwide venue deployments. Led development of an Android-based background music solution built in C#/.NET (Xamarin). Designed and implemented secure device communication using REST APIs, sockets, and FTPS, ensuring reliable content delivery to distributed jukebox units. Built and maintained internal content and estate management systems using ASP.NET, C#, jQuery, HTML5, CSS, and JSON-based REST services. Modernised a legacy PHP/MySQL platform supporting >100TB/week music distribution at peak. Championed DevOps adoption, implementing CI/CD pipelines and improving deployment reliability and release speed. Contributed to modernisation efforts using .NET Core 8, Node.js, and React.
Senior Software Engineer / Team Lead at AS&K Communications
December 1, 2011 - January 1, 2014
Developed and maintained web, mobile and desktop applications primarily using C#, ASP.NET and SQL Server (Entity Framework) for major pharmaceutical clients. Led the backend development team, coordinating with frontend and mobile teams to deliver integrated solutions. Designed adaptive HTML5 web platforms supporting multi-video delivery across devices and browsers. Built interactive trade-show applications including Kinect-based booth experiences. Guided architectural decisions and ensured secure, scalable deployment of client-facing platforms; collaborated with stakeholders to translate business requirements into deliverables.
Software Developer at Question Mark Computing Ltd
December 1, 2009 - December 1, 2011
Developed cross-device PHP front-end applications integrated with a .NET back-end SaaS service. Built responsive web interfaces supporting iOS, Android and both modern and legacy browsers. Worked with MSSQL and Oracle databases; implemented features using XHTML, CSS, JavaScript (jQuery), AJAX and XML/XSL.
Self-Employed at B Systems VOF (The Netherlands) Computer Services Company
July 1, 2008 - December 1, 2009
Founded and operated web development consultancy in the Netherlands. Built and maintained high-traffic PHP/MySQL platforms exceeding 10 million monthly page views. Managed Linux server infrastructure and security.
Software Developer at Question Mark Computing Ltd
November 1, 2006 - July 1, 2008
Maintained and extended ASP.NET and Win32 applications for internal and customer-facing systems. Supported legacy codebases including Classic ASP, C++, and Java. Worked with Microsoft SQL Server and Oracle databases; diagnosed and resolved production issues to improve stability and reliability.
Software Developer at Enable Software Ltd
January 1, 2003 - January 1, 2006
Summer/early years development work focusing on Classic ASP, ASP.NET, C#, and MSSQL; frontend work with CSS2, XHTML; ensuring cross-browser compatibility.
Software Developer at BSystems VOF (The Netherlands) - Self Employed
July 1, 2008 - December 1, 2009
Founded and operated a web development consultancy in the Netherlands. Built and maintained high-traffic PHP/MySQL platforms exceeding 10 million monthly page views. Managed Linux server infrastructure and security.

Education

BSc(Hons) Computer Science at University of Portsmouth
January 1, 2003 - January 1, 2006
BSc (Hons) Computer Science at University of Portsmouth
January 1, 2003 - January 1, 2006

Qualifications

Add your qualifications or awards here.

Industry Experience

Media & Entertainment, Software & Internet, Professional Services
    ImmichVideoSlideshow open source project

    https://www.twine.net/signin

    Home Video Channel is a lightweight video slideshow app I developed for playing personal videos from an Immich photo library, with both a native Apple TV/tvOS app and a browser-based web player. It supports continuous random or sequential playback, favourites, hiding videos back into Immich, metadata and stats overlays, channel-style browsing by time, albums, people and search, plus local caching and sync tools for larger libraries. I built the project using SwiftUI for Apple TV, a PHP/Docker-based web player, SQLite caching and the Immich API, while making active use of AI tools throughout development to help prototype features, explore implementation options, speed up iteration and improve documentation, while still reviewing, testing and shaping the final product myself.