I am a software engineer interested in design and implementation of programming languages, compilers, runtime systems, low-level and systems programming, performance optimization. I occasionally give talks about these topics

Currently, I work at Google as an overall technical lead for the Dart programming language. I joined the team in 2012 to design and implement a speculative optimizing JIT in the Dart VM. The compiler pipeline that we have created later became the foundation for Dart's native AOT compiler.

In 2016 I had a brief stint at DeepMind maintaining LuaJIT for them.

Before joining Dart I was part of the V8 JavaScript engine team at Google. Here I contributed to Crankshaft and efforts to modernize V8's GC. I have been involved in OilPan - effort to replace reference counting based memory management in Blink with an precise-on-heap mark-and-sweep GC.

I started my carrier working on Excelsior JET a proprietary Java VM with an AOT compiler.

2025

Reading in 2025

Jan 2025

2024

My year in books

Dec 2024

Microbenchmarks are experiments

Taking a look at a viral loops microbenchmark which like many other similar microbenchmarks does not measure anything useful or insightful. Nov 2024

2023

My Setup

Feb 2023

2021

Microbenchmarking Dart (Part 1)

Are fixed-length lists really 43 times faster to allocate than growable ones? Jan 2021

2018

Maybe you don't need Rust and WASM to speed up your JS

Mozilla sped up the source-map library by rewriting its core in Rust and compiling it to WASM. I am taking a look at JavaScript version in an attempt to make it faster. Feb 2018

2017

The fear of dart:mirrors

Is dart:mirrors really to blame for slow JSON deserialization? Jan 2017

2016

Adventures in the land of substrings and RegExps.

Why is String.substring slower in Dart VM than in V8, and what does it have to do with less_dart being slow? Nov 2016

2015

Crankshaft vs arguments object

Nov 2015

jsunderhood digest (in Russian)

A Russian-language digest of my week running the @jsunderhood Twitter account, answering questions about V8 internals. Apr 2015

Browser as an Interactive Disassembler

Trying to understand why HotSpot's C2 turned one loop into three led me to build Saga, a toy browser tool that rebuilds a CFG and an SSA IR from disassembly to make it readable. Mar 2015

What's up with monomorphism?

What do monomorphic, polymorphic and megamorphic actually mean? A tour of how inline caches collect type feedback and how V8's optimizing compiler uses it, and why too many shapes at one call site hurt performance. Jan 2015