About Me

Find Me

Mastodon @zero@itsze.ro
Threads @itszero@threads.net (Mostly in Taiwanese Chinese)
Twitter
Email contact@zero.taipei

Résumé

Zero Cho, a.k.a 傑洛

📍 San Francisco Bay Area

Work Experiences

OpenAI

Member of Technical Staff
2026/03 - now

Fleet Scheduling Team
Works on GPU Kubernetes scheduler / cluster and management UI

Iago Education Inc.

Co-founder
2022/08 - 2025/10

Grew the company to 12k+ MAU (Monthly Active Users) and 2k+ paid users
Championed the company’s pivot to a visual novel game app with AI conversation practices; User session length grew to ~45mins (5x of Duolingo)
Created a state-machine based system for LLM conversation alignment: Reduce context window needed by 60% and reduce retries when LLM goes out of alignment
Implemented distributed tracing to identify and solve a multi-threading bottleneck and DB contention problem, reducing response time from 500ms to 50ms
Made the company’s core-tech “Linguistic Pipeline”: word tokenization, Part-of-Speech tagging and custom DSL grammar recognition

Robinhood Markets, Inc.

Engineering Manager
2020/08 - 2022/07

Web Engineer
2018/07 - 2020/08

(EM) Created and led the frontend teams (iOS, Android and Web) for Retirement (IRA) from start to launch
(EM) Managed a cross-functional (Security/Legal/DevOps/more) team as both EM/PM to develop the internal SEV(Severe) incident managing tool; and a team worked on Original Content Sites: support center, newsletter, podcasts
(IC) Led the web efforts for Robinhood UK expansion (Marketing Website, Support and web app changes); Partnered with legal team for UK legal restrictions, GDPR works and the local team for launch and marketing support
(IC) Worked on the Web teams’ monorepo migration: custom git tools to merge repos, deploy dashboard, phabricator integration and cross-team communication for a no downtime, painless migration
(IC) Built complex and performant Advanced Trading Charts and Testing tooling; Partnered with support agents to improve their tools

Twitter, Inc.

Senior Software Engineer
2016/08 - 2018/06

Software Engineer
2014/06 - 2016/08

Software Engineering Intern
2013/05 - 2013/07

Core member of Twitter Lite (later became the current Twitter Web): Twitter’s data-conscious React progressive web app frontend
- Built LazyList – A smart, virtualized infinite list renderer, essential to the site’s initial launch
- Launched Night Mode – live full-app color scheme switching
- Added KaiOS support – Fit the app on 2G network (Data Saver mode) and keypad phones to support emerging market where we see huge Twitter growth
Major contributor to Twitter’s new Web CI framework: test runner, report aggregation, Monorepo support, parallel execution, browser matrix support, commit sign-offs, etc
Redesigned Twitter Export backend (Scala): eliminated 95%+ of weekly operational alerts; enabled multi-datacenter deployment with automatic failover, saving hundreds of engineering hours

KKBOX, Inc.

Contractor
2012/01 - 2012/08

Mobile and web platforms research
Prototyped Android Custom UI components
Prototyped HTML5/Javascript Game

MediaTek, Inc.

Software Engineering Intern
2011/07 - 2011/08

Android System Team
Developed GDB/Python extensions for kernel dump forensics

hypo

Developer
2008/08 - 2011/09

Individually developed web editors for Ticket and Wide
Maintained PDF framework in Cocoa and its Ruby DSL wrapper
iOS application development
Mac OS X / Linux System Administration

NCU eecesnmg

Leader
2007 - 2010

System Network Management Group, Department of Electrical Engineering & Communication Engineering, National Central University
Lead the group for the major system transition (FreeBSD 4 to ArchLinux)
Experiences of major system failure recovery (Hard disk failure due to power outage)

Education

Georgia Institute of Technology

Atlanta, GA, USA
MS Computer Science
2012/08 - 2014/05

Advisor: Calton Pu on Elba and LITMUS
Dropped out of PhD

National Tsing Hua University

Taipei, Taiwan
MS Computer Science
2010/09 - 2012/06

Advisor: Pai H. Chou on ecomote
GPA: 4.0/4.0

National Central University

Taoyuan, Taiwan
BS Communication Engineering
2006/09 - 2010/06

Overall GPA: 3.1/4.0
Major GPA(Computer Science): 3.7/4.0

Exam Scores

TOEFL-iBT Total: 107 (R: 29, L: 28, S: 23, W: 27)
GRE V 149/42%, Q 163/88%, AWA 3.5/29%

Publications

Journal Papers

Chih-Lin Hu and Chien-An Cho, “User-provided multimedia content distribution architecture in mobile and ubiquitous communication network”, Journal of Network and Computer Applications, Vol. 34, pg. 121-136, January 2011 [Paper]

Chih-Lin Hu, Chien-An Cho, Chang-Jung Lin and Chen-Wei Fan, “Design of mobile group communication system in ubiquitous communication network”, IEEE Transactions on Consumer Electronics, Vol. 56, pg. 88-96, Feburary 2010 [Paper]

Chih-Lin Hu and Chien-An Cho, “A Novel Mobile Content Delivery Scenario with Simple Double-Key Secure Access Control,” International Journal of Security and Its Applications, Vol. 3, No. 1, pp. 1-16, January 2009. [Recommended by UMC’08] [Paper]

Conference Papers

Chih-Lin Hu, Chien-An Cho, Chang-Jung Lin, Chen-Wei Fan, “A location tracking and messaging system for mobile group communication in IP networks,” International Conference on Consumer Electronics (ICCE), 2010 [Paper]

Chih-Lin Hu, Chien-An Cho and Po-Jung Wang, “Secure Mobile Content Delivery Architecture in Hybrid Network Environment,” accepted by the 2008 International Symposium on Ubiquitous Multimedia Computing (UMC’08), Hobart, Australia, Oct. 13-15, 2008. [Rate: 22% (46/201)] [Paper]

Patents

Chih-Lin Hu, Chien-An Cho and Po-Jung Wang, “System and method of mobile content sharing and delivery in an integrated network environment,”, US Patent App 13/338,489 [ref]

Chih-Lin Hu, Chien-An Cho, Chen-Wei Fan, Chang-Jung Lin, “System and method of mobile group positioning,”, US Patent App 12/654,050 [ref]

Awards

eBay GaTech Hackathon ‘13

2nd Prize
eBay

Facebook graph search for eBay items

Taipei Fun App Contest ‘11

1st Prize
Taipei City Government

TaipeiFever, an Android guide book app

Embedded System Contest ‘11

Honorable Mention
Ministry of Education, Taiwan

Augmented Reality Home Controller

Telecom Value-Added Contest ‘10

Honorable Mention
Chunghwa Telecom

Home automation system integrated with MOD and sensor network

WWDC Scholarship ‘09

Apple Inc.

MobileHero Android Software Contest ‘09

2nd + Google Prize
Ministry of Economic Affairs. Taiwan

KerKerInput, an Android Chinese Input Method framework

Telecom Value-Added Contest ‘09

1st Prize
Chunghwa Telecom

SLIMA, A location-based photo blogging system with timeline

ICSCA Contest ‘09

1st Prize
Ministry of Education, Taiwan

ICSCA: Internet Communication Softwares and Creativity Application
Inter-vehicle Communication System on Android

Software Creativity Contest ‘08