Xuejie Xiao

Succinct Senior Software Engineer / Remote / 2025 - 2026

Started on a consulting contract working on SP1's Arbitrum integration, later converted to full-time Senior Software Engineer. Departed in a company-wide reduction.

• Co-designed and implemented SP1's Arbitrum integration, enabling Arbitrum to use SP1 as a proving backend.
• Optimized SP1's RISC-V VM to ~3× its original throughput through targeted micro-architectural work.
• Built a process-based sandbox for JIT code isolation.
• Extended Wasmer to support RV32 as a target and improved its RV64 support.

Cryptape Staff Software Engineer / Remote / 2018 - 2025

Joined to build Nervos CKB, a permissionless layer-1 blockchain. Grew into engineering leadership, including a period as CTO, then returned to a senior IC role to focus on deep VM and systems work.

• Designed, implemented and led development of CKB VM, the core virtual machine used in Nervos CKB. To the best of my knowledge, CKB VM is the first blockchain VM using RISC-V ISA. As a suite of VM implementations, CKB-VM features a hand-tuned assembly-based interpreter inspired by LuaJIT, and an LLVM-based AOT engine running in roughly 2.34× the time of native x86_64 code.
• Led development of libraries and tools pioneering RISC-V software ecosystem in blockchains, including build skeletons to simplify development work, deep RISC-V program optimizations, libc / libc++ porting for CKB, and comprehensive security analysis.
• Contributed to Nervos CKB with system-level insights, including the design of spawn syscalls, and flaky test debugging.

Citrusbyte (now TheoremOne) Software Engineer / Remote / 2013 - 2018

Worked on and led teams building diverse projects spanning web apps, embedded systems, and Linux kernel technologies. Led the engineering team on a major Apple Store supporting project that was featured in an Apple Keynote.

Google Software Engineer Intern / Shanghai / 2010 - 2011

Worked in the AdWords team, helping build a series of internal and external tools, including a conversion tool for importing advertising campaigns from Sklik into Google AdWords, a visualization tool for presenting AdWords potential conversion results to advertisers, and a range encoding algorithm for compressing URLs on the fly by exploiting URL patterns.

Open Source Work Anywhere / 2011 - Now

I've also contributed to open source projects from time to time. Since much of my professional work is itself open source, I will only include selected personal projects here:

• diviner: a FoundationDB style simulation testing framework. I've written a complete post describing this project here.
• paguridae: a Web IDE inspired by acme, using simplicity driven design principles.
• sohm and sohm.lua: a scalable variant of the Object-hash mapping library for Redis. The lua version was written to leverage extreme performance provided via OpenResty. The sohm.lua library has been deployed in an environment where 200,000+ queries per second were recorded at peak time.
• webruby: webruby brings mruby, a lightweight Ruby implementation to the browser, enabling one to run Ruby code in the browser environment. Note this project compiles mruby into asm.js, which is the predecessor of WebAssembly. I've also been learning and trying WebAssembly since then to keep a knowledge of WebAssembly's nuts and bolts.

• A Journey to the Limit — building an LLVM-based AOT engine that runs in roughly 2.34× the time of native x86_64 code
• Against ROP Attacks
• Deterministic Debugging of CKB's Flaky Tests
• A Journey Optimizing CKB Smart Contract
• Towards a True Programmable Blockchain World (talk)

Systems Programming

I have extensive low-level systems programming experience. I have authored and optimized virtual machines where bottleneck lies in modern CPU micro-architecture, tweaked software for embedded devices with extremely low memory, and modified Hadoop to unlock additional performance.

Virtual Machines

I introduced RISC-V as a practical VM architecture for blockchains through CKB-VM in 2018 and have helped pioneer its ecosystem since.

I've been working with WebAssembly related technologies from the very beginning, whether it is emscripten, LLVM, asm.js or the current WebAssembly. I'm also up to date with the latest progress, both in the implementations, and in software that relies on WASM.

Software Design

Throughout my career I've practiced with simplicity driven design. I firmly believe simplicity is the most effective weapon against complicated computer systems, as well as ever-changing domain logic.

Polyglot Programming

Throughout my career I've been dealing with many different technologies. I'm proficient in C/C++, Rust, Go, Ruby, JavaScript, low-level assemblies on x86-64, aarch64 and RISC-V. I also have experience (but to a lesser extent) in Java, Erlang/Elixir, Lua, Python, Coq, C#, etc.

Syracuse University PhD Fellowship Program, unfinished / 2011 - 2013

Major: Electrical and Computer Engineering

• A cross-job framework for MapReduce scheduling
• Sensing as a service: A cloud computing system for mobile phone sensing

Tongji University Bachelor / 2007 - 2011

Major: Software Engineering. Graduated 1^st in class.