Compiler backends
Keeping Singlepass linear and LLVM fast on huge modules.
Work at Help reimagine the entire compute stack
Drag to turn, click a layer to enter.
What we work on
Our work runs from compiling down to machine code all the way up to a globally distributed cloud, and we solve many hard problems along the way.
Sandboxing
WebAssembly can't express a system call, so a module acts through imports, and WASIX exposes only what you granted. A miscompile or a bad host call is a sandbox bug.
VMs and containers
All three run untrusted code, and costs follow from where the boundary sits.
Virtual machines
Every guest stores and boots its own kernel, drivers and userland.
Containers
Programs make real system calls into a kernel shared by every container.
Wasmer
Software has to be compiled for WASIX, and then one file runs on x86-64, ARM and browsers with no guest kernel.
Runtime
Wasmer compiles WebAssembly with three backends. Singlepass walks each function once with no IR, so compile time stays linear. Cranelift and LLVM take longer and emit faster code.
Ecosystem
- wasix-libc extends wasi-libc with fork and
dlopen. - wasixcc wraps clang, and our Rust fork adds WASIX targets.
- Wasinix builds software in bulk with Nix.
- Edge.js runs Node apps, and PHPix serves PHP.
- Anybuild detects and builds projects.
Registry
WebC, our package format, is inspired by language package managers and Docker images. An index at the front records each file's byte range and SHA-256, so Wasmer mounts volumes without unpacking. Browse the registry
Wasmer Edge
Edge is our cloud, with the same Rust binary on every node. Nodes share only the package store, so a partitioned node keeps serving. InstaBoot restores warm-up snapshots on cold starts. Edge docs
Why work at Wasmer
When CPython misbehaves, the cause might be our port, the libc, a host call or a backend, and we can fix any of them.
If you know kernels you'll recognize most of WASIX, except the kernel here is a Rust library.
What you could work on
Processes and threads
Fork, exec and signals without a copyable stack.
Dynamic linking
Updating every thread's function table on dlopen.
Journaling and snapshots
Capturing every thread's stack, memory, files and sockets.
Linux compatibility
Futexes, epoll and mmap against the Linux Test Project.
Toolchain and ports
LLVM, Rust and Go forks, and crates like tokio.
Language runtimes
Porting Node onto N-API and running Django and WordPress.
The browser
WASIX host code in a tab, TCP through WISP.
Package format and registry
WebC's manifest, dependency resolution and the Rust backend.
Wasmer Edge
Snapshot distribution, private networking, volumes and databases.
Much of this is open source, with the runtime and WASIX in wasmerio/wasmer (start with proc_fork.rs), the toolchain in wasix-org and Edge.js in wasmerio/edgejs.
Who we need
We're a small startup, so we look for these six things in everyone we hire.
- High agency
- You see what needs doing and start on it without being asked.
- Passion for building something new
- You get excited about software that doesn't exist yet, and you want to be the one who builds it.
- Ownership of the whole problem
- You take a piece of work from idea to production, and you stay with it once people depend on it.
- Quick learning in unfamiliar areas
- Much of this work has you reading specs and source code in an area you haven't worked in before.
- Directness and honesty
- You say what you think, take blunt code review well, and are upfront about what you don't know.
- Embracing AI in every workflow
- You use AI in all parts of how you work, and you keep looking for more places it helps.
Compile once for WASIX, and the package runs on your laptop, in a browser or on Edge.
Apply now
Or email hiring@wasmer.io with what you've built.