Company: Remote (CET ± 2)---Build an operating system that runs everywhereMost engineers spend their careersusingoperating systems. ¿It's the kind of problem where you're reading Linux kernel source in one tab and the WebAssembly spec in another, deciding how mmap should behave on a platform that was never designed to have one. What you'll work onWASIX itself— designing and implementing syscall semantics, process and threading models, virtual filesystems, and networking stacks on top of WebAssembly.

Where

Linux behavior and Wasm constraints collide, you'll be the one deciding what "correct" means. Making real software just work— porting and running battle-tested Unix software (curl, bash, PostgreSQL-class programs) unmodified on WASIX, and fixing everything that breaks along the way. Open source- a good chunk of your work will ship publicly, in one of Wasmers open-source repositoriesYou're probably a fit if youHave5+ yearsof systems-level engineering experience, with real-world work onLinux internals, hypervisors (KVM, Xen, Firecracker, etc.), KnowPOSIXdeeply: processes, signals, sockets, file descriptors, memory management — the stuff most people only meet through man pages.

Thrive withhigh ownership :



you can take a fuzzy problem ("make signals work correctly under Wasm") and drive it from design to shipped code. Adaptable and or remote work policiesMonthly fitness stipend. WASIX already runs real software for real developers — which means your design decisions get stress-tested immediately, not in five years.

You'll join a small, senior, remote team where the interesting problems aren't handed down from an architecture committee — you'll find them, scope them, and solve them.

About Wasmer

Wasmer builds the software powering the next generation of computing platforms — local, cloud, and edge — on WebAssembly. Just as Node. Js unlocked server-side JavaScript, we're unlocking server-side WebAssembly for every language: C/C++, Rust, Go, Python, and beyond. Our mission is to make software universally available. We're an open-source-first company, and we believe the best infrastructure is built in public.

How to apply Send us your CV or LinkedIn — but honestly, we care more about yourGitHub, a project you're proud of, or a war storyabout the gnarliest low-level bug you've ever fixed. Wasmer is a remote-first company.

📌 Senior Engineering Systems Engineer (Madrid)
🏢 WASMER
📍 Madrid