Assembling Me

I build compilers, WebAssembly runtimes, programming languages, and developer tools. I write about optimization, WebAssembly GC, fuzzing, code generation, runtime design, and the problems I find while building them.

Joshua Tenner

Software developer building compilers and WebAssembly tools

What I’m building

One set of tools, from source code to system calls

These are separate projects, but they meet at the same boundary. Dewdrop produces WebAssembly GC. Starshine works on WebAssembly modules. Wago runs them. Facet gives guests access to host services. Stage Left explores isolated processes. as-harness tests code across replaceable WebAssembly hosts.

I use this site as an engineering record. Project pages describe the current design. Older articles remain dated snapshots, with update notes when the project has changed in an important way.

WASM

Introducing sfo-mb: a beginner-friendly guide to a MoonBit type checker

A simple introduction to sfo-mb, with practical examples of terms, types, kinds, traits, and borrow checks.

Joshua Tenner
WASM

Introducing as-harness, a new testing framework for AssemblyScript

A practical introduction to as-harness, a Wasm-first AssemblyScript test framework with deterministic planning, coverage, snapshots, and multiple runtime hosts.

Joshua Tenner
AI

AGENTS.md is a package.json for your agents

How to give coding agents the small set of repository rules, commands, and workflows they need to work safely.

Joshua Tenner
Coding

Hello, world

A short introduction to what I build and what I write about on this site.

Joshua Tenner