Joyee Cheung's Blog

Teaching gdb to Unwind V8 JIT Frames on x64

2026-03-23T23:00:00.000Z

Recently I landed a custom Python gdb unwinder in V8 that allows gdb to unwind through V8’s JIT-compiled frames on x64

Tinkering with Node.js Core on ARM64 Windows

2026-01-31T09:50:00.000Z

A while back, I wrote about Building Node.js on Windows using the new ClangCL support, which was done on an actual x64 Windows machine

Improving Single Executable Application Building for Node.js

2026-01-26T11:00:00.000Z

Recently, I landed a change that moves the Single Executable Application (SEA) build process directly into Node.js core - a hobby project I’d been tinkering with for some time

require(esm) in Node.js: implementer's tales

2025-12-30T09:30:00.000Z

In earlier posts, I wrote about reviving require(esm) and its iteration process

require(esm) in Node.js: from experiment to stability

2025-12-30T09:00:00.000Z

More than a year ago, I set out to revive require(esm) in Node.js and fixed a macOS-specific startup performance regression in Node.js after an extensive investigation. Along the way, I learned a lot about tools for macOS and Node

Reproducible Node.js built-in snapshots, part 3 - fixing V8 startup snapshot

2024-09-28T08:44:09.000Z

In the previous posts we looked into how the Node.js executable was made a bit more reproducible after the Node.js snapshot data and the V8 code cache were made reproducible, and did a bit of anatomy on the unreproducible V8 snapshot blobs

Reproducible Node.js built-in snapshots, part 2 - V8 code cache and snapshot blobs

2024-09-28T07:44:09.000Z

In the previous post, we covered how the Node.js built-in snapshot is generated and embedded into the executable, and how I fixed the Node

Reproducible Node.js built-in snapshots, part 1 - Overview and Node.js fixes

2024-09-28T06:44:09.000Z

In a recent effort to make the Node.js builds reproducible again (at least on Linux), a big remaining piece was the built-in snapshot. I wrote some notes about the journey of making the Node

Things I learned from organizing a hybrid unconference

2024-04-21T10:00:00.000Z

Recently, I co-organized a hybrid unconference - the Node.js collaboration summit for 2024 H1

require(esm) in Node.js

2024-03-18T17:10:26.000Z

Recently I landed experimental support for require()-ing synchronous ES modules in Node.js, a feature that has been long overdue

Memory leak regression testing with V8/Node.js, part 3 - heap iteration-based testing

2024-03-17T17:48:11.000Z

In the previous blog post, I described the heap snapshot trick as an “abuse” of the heap snapshot API, because heap snapshots are not designed to interact with the finalizers run in the heap

Memory leak regression testing with V8/Node.js, part 2 - finalizer-based testing

2024-03-17T17:38:11.000Z

In the previous blog post, I talked about how Node.js used memory usage measurement to test against memory leaks. Sometimes that’s good enough to provide valid tests

Memory leak regression testing with V8/Node.js, part 1 - memory usage-based testing

2024-03-17T17:28:11.000Z

Like many other relatively big piece of software, Node.js is no stranger to memory leaks, and with them, fixes and regression tests

Fixing Node.js vm APIs, part 4 - hitting the compilation cache again

2023-12-31T20:28:11.000Z

In the last post I wrote about how I finally managed to fix the memory problems in the vm APIs, and it turned out that there was another issue blocking users from upgrading away from the End-of-Life Node

Fixing Node.js vm APIs, part 3 - verifying the fixes

2023-12-30T19:28:11.000Z

In the last post I wrote about how a new memory management model in Node.js vm APIs was designed to fix the long-standing leaks and use-after-free issues, and we finally put together a PR that the Node

Fixing Node.js vm APIs, part 2 - reworking the memory management

2023-12-30T18:28:11.000Z

In the last post, I wrote about how I came to work on a memory leak in the vm compilation APIs in Node

Fixing Node.js vm APIs, part 1 - memory leaks and segmentation faults

2023-12-30T17:28:11.000Z

This year I spent some time fixing a few long-standing issues in the Node.js vm APIs that had been blocking users from upgrading away from Node.js v16 (End-of-Life). It had been an interesting journey, so I decided to write a few blog posts about it. Hopefully they can be helpful for posterity

Fixing snapshot support of class fields in V8

2022-04-14T15:21:39.000Z

Up until V8 10.0, the class field initializers had been broken in