Marnix Janssen
Full Stack Engineer at Polars
Rotterdam, South Holland, Netherlands
Summary
👤
Senior🎓
Top SchoolMarnix Janssen is a Full Stack Engineer based in Rotterdam with 13 years of hands-on experience building web applications end-to-end. He started in PHP and evolved into a JavaScript and TypeScript specialist before expanding into type-safe back-end work with Rust, designing services that handle millions of requests and high-throughput PDF rendering pipelines. At Check he built critical internal tooling and microservices (Rocket, Redis, AMQP, Next.js, Bun/Elysia) and now continues to shape architecture and full-stack features at Polars. Known for connecting front-end UX needs with robust back-end design, he combines technical depth with an extroverted team-first mindset that helps inspire and mentor colleagues. Outside work he treats coding as a passion—“I smash code”—and balances it with bouldering and social team culture.
12 years of coding experience
13 years of employment as a software developer
Bachelor of Applied Science - BASc Mediatechnologie, Bachelor of Applied Science - BASc Mediatechnologie at Rotterdam University of Applied SciencesWebmaster Mediatechnologie, Webmaster Mediatechnologie at Grafisch Lyceum Rotterdam
Dutch, English
Github Skills (176)
cms10
api-platform10
dashboard10
api-client10
telegram10
modifiers10
rest-api10
javascript10
no-code10
browser10
api10
rest10
mysql10
static-site-generator10
typescript10
Programming languages (9)
Github contributions (5)
mjanssen/graduation-frontend-setups
Apr 2017 - Aug 2017
Contributions:129 commits, 3 PRs, 116 pushes in 4 months
webpack-configurationsetupsjavascriptview-layerwebpack
mjanssen/koekie
Aug 2018 - Apr 2019
Contributions:27 commits, 5 pushes in 8 months
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