Jeffrey Charles
Senior Software Developer at Shopify
Waterloo, Ontario, Canada
Summary
🤩
Rockstar🎓
Top SchoolJeffrey Charles is a Senior Software Developer in Waterloo with 14 years of experience building backend systems and streaming pipelines for companies from startups to enterprise. He specializes in WebAssembly and Rust—contributing to prominent open-source runtimes like Wasmtime and tooling such as Javy—while also shipping production services in Go, Scala, Ruby and Node. At Shopify he helped design a WASI hostcall for logging and migrated merchant reporting to an Apache Flink pipeline; earlier roles include architecting real-time analytics at Vidyard and IoT prototypes at Canadian Tire. He combines systems-level compiler work (implementing new Wasm instructions and AArch64 debug support) with practical delivery: CI/CD, Terraform, and continuous deployment patterns. Known for tackling unusual problems, he moves comfortably between low-level runtime internals and large-scale data pipelines.
14 years of coding experience
12 years of employment as a software developer
Bachelor’s Degree, Honours Business Administration, Bachelor’s Degree, Honours Business Administration at Wilfrid Laurier University
Stackoverflow
773reputation
16kreached
16answers
4questions
Github Skills (19)
avx10
data-serialization10
wasi10
serialization10
compiler-design10
text-encoding10
quickjs10
rust10
webassembly10
build-automation9
cran9
jit9
arm9
hashtable6
dictionary6
Programming languages (14)
Github contributions (5)
bytecodealliance/javy
Feb 2022 - Jan 2023
JS to WebAssembly toolchain
Role in this project:
Back-end Developer
Back-end DeveloperContributions:15 releases, 340 reviews, 98 commits in 11 months
Contributions summary:Jeffrey primarily focused on modifying and refactoring core components related to the QuickJS WebAssembly toolchain. They renamed crates, removed vendored dependencies, and updated the build process for WASI-SDK integration. Further contributions included extracting serialization into a separate crate, implementing text encoding APIs, and updating benchmarking code. These changes aimed to improve the toolchain's functionality, maintainability, and build process.
javascriptwebassemblytoolchainassemblyscriptwasm
bytecodealliance/wasmtime
Jul 2022 - Jul 2022
A lightweight WebAssembly runtime that is fast, secure, and standards-compliant
Role in this project:Back-end Developer
Back-end DeveloperContributions:18 reviews, 2 commits, 59 PRs in 11 days
Contributions summary:Jeffrey contributed to the core logic of the wasmtime runtime, focusing on implementing support for new WebAssembly instructions. Their work included adding functionality to Winch, a WebAssembly to machine code compiler, and enabling features such as debug symbol generation on AArch64. The user's contributions demonstrate a focus on extending the runtime's capabilities to support a wider range of WebAssembly features, particularly integer comparisons and conversions, by modifying code related to the compiler's visitor implementation.
securejitcraneliftrustruntime
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