Yu Xiang
✰ Past: Infra / Cloud Eng / Android @ByteDance ;
✰ Present: Generative AI Enthusiast / K-line Enthusiast / @QodoAI.
✰ Past: Infra / Cloud Eng / Android @ByteDance ;
✰ Present: Generative AI Enthusiast / K-line Enthusiast / @QodoAI.
Contributed to CodiumAI, an Israeli AI startup, as an open-source developer, participating in the design, development, maintenance, and deployment of two core projects: PR-Agent and Cover-Agent.
These tools leverage AI-driven solutions to enhance the efficiency and automation of continuous code review and continuous testing. CodiumAI has completed two funding rounds: an $11M Seed round in 2023 and a $40M Series A in 2024.
Responsible for engineering productivity, focusing on optimizing development processes and addressing pain points related to release quality, covering areas such as establishing engineering standards, managing release quality, and shifting quality controls leftward.
Established and implemented comprehensive release management SOPs, including standardized MR workflows, gray release strategies, stability monitoring, and hotfix mechanisms. These measures significantly reduced delays and skipped releases (quarterly skips ≤ 3, minor release rate ≤ 10%, code freeze time decreased from 7.67h to 5h).
Additionally, led the development of internal productivity tools featuring automated batch MR integrations, issue auto-attribution, and IM-based automated notifications, resulting in a productivity improvement exceeding 60% (daily OnCall workload reduced from 9 PD to 3.5 PD).
Responsible for three product lines within the Quality Infra, including annual planning, product design, technical implementation, and facilitating cross-team collaboration and KA business integration:
Performance Analysis System:
Client-side (ByTrace): Developed diagnostic tools for performance regression attribution during the development stage, including single-trace analysis (Tracery) and aggregate comparison analysis (Comparison View).
Server-side (ByteHunter): An AIOps solution providing alarm suppression and root cause analysis.
Testing Services (App Competitor Evaluation): Time-based benchmarking using high-speed cameras and frame-by-frame video analysis; resource-level benchmarking using low-level performance metrics (e.g., CPU, Memory) collected via PerfAgent and Diggo.
Intelligent Testing (SmartEye): Precision testing and code coverage analysis tools, enabling intelligent test case minimization and optimization.
Product:
UC Browser Mini
InfoFlow feature development: participated in business architecture refactoring and led the design and implementation of the Router component.
Optimized app performance, KPI improvements in crash rates, UI responsiveness, and launch times.
Independently delivered two innovative short-video applications targeted specifically at the Indonesian market.
Flyme Performance Team Member
Identified and implemented performance optimizations within the AOSP.
Developed and delivered new system-level features for Flyme OS.
Maintained the Android graphics stack, managed SurfaceFlinger and HWUI codebases, and resolved graphics-related issues on MediaTek and Samsung platforms.
Led performance optimization for select smartphone models, maintained comprehensive optimization checklists, and ensured successful implementation and validation.
Communication and Information Systems, GPA: 87.4
Information Engineering, GPA: 88.6
Delivered a technical talk Alibaba's "匠心堂" on Android Graphics.
Mobile App Testing at Scale - Regression and two performance analysis tools
Android performance Overview at ByteDance Infra, covering optimizations in Douyin and Toutiao, and OS-level improvements.
Color Mix Buddy
A simple and user-friendly online color mixing tool that supports various mixing algorithms and color selection options. Features multiple color mixing algorithms, built-in palette with predefined colors, and mix history feature.
Fancy Text Formatter
This is a modern web-based tool that transforms English text into stylish Unicode fonts—such as Bold Serif, Bold Sans, Italic Serif, and Italic Sans—within a clean, Apple-inspired user interface. It preserves all non-English characters, including Chinese, punctuation, spaces, and line breaks, ensuring seamless multilingual input.
Perfetto Plus
I extended Google's Perfetto project to support the Nanoscope protocol—an extremely low-overhead method-tracing solution for Android. By modifying the ART, Nanoscope traces Java method calls with minimal performance impact, incurring only around 10 milliseconds of overhead even when tracing millions of method calls on the main thread.
The tracing strategy is as follows:
The output format is a simple, human-readable push/pop structure, pattern:
[timestamp]:[methodSignature | "POP"]
Why not Google Trace Event Format because it proved excessively verbose and inefficient at handling millions of trace events, slowing both the generation and parsing of trace files.
Video Transcribe
This project uses OpenAI Whisper to generate high-quality subtitles from local video files or YouTube links, supporting Chinese and other languages, with built-in 360p video download, WAV audio extraction, optional timestamps, and a simple, flexible CLI.
The model will be downloaded automatically on first run and cached in the default directory ~/.cache/whisper.
Chrome Extension: Enhanced Screenshot
A browser extension designed to enhance screenshot functionality with beautiful backgrounds and customization options.
Day Trading @ U.S. Stock Market
I have a Bear blog where I collect ideas on technology, product, and AI learning.