- Joined
- Jul 2026
- How they joined
- Directly
- Before Cognition
- ProbookFounding Engineer #1
- Status
- Current
Overlapped before Cognition
Sources1linkedin.com
Details
LocationSan Francisco Bay Area
Company sitecognition.ai
TeachingEnglishAlgorithmsProblem SolvingProgramming
Notes
- Only public post about working at Cognition, resharing Cognition's $1B annualized revenue announcement, verbatim: "More than doubled since just two months ago when I joined 🤯"Sep 25, 2026
- Joined Cognition (makers of Devin and Windsurf) as Member of Technical Staff in San Francisco in July 2026; LinkedIn headline reads 'Agents Engineer'.Jul 2026
- Own post at Probook's one-year mark: "One year ago I joined Probook AI as founding engineer #1. Today: over 1,400 commits and 1,000,000+ lines of code shipped."Apr 8, 2026
- Probook co-founder Lewis Z. (Lewis Zhang) recruited him and says he has known Yibo for 15 years; Lewis wrote that Yibo wrote 1 million lines of code at Probook in under a year and the team threw him a crawfish boil.Mar 25, 2026
- Founding Engineer #1 at Probook (AI operating system for home services, NYC, backed by Sequoia and a16z) from 2025 to July 2026, then an advisor to Probook through August 2026.2025
- ICPC 2020 World Finals (Moscow, held 2021): placed 56th for Virginia Tech as team '46 is a Prime Number' with teammates Alexander Lind and Benjamin Reidys, solving 5 problems.Oct 2021
- Did not arrive at Cognition through an acquisition: he came directly from Probook (no Cognition-Probook deal found). Cognition's acquisitions were Windsurf (2025) and The Interaction Company, makers of Poke (announced July 2026, the same month he joined).Jul 23, 2026
- Probook $40M announcement post: "Over a year in, I've shipped multiple products from zero to hundreds of customers"; problems he named were "Real-time voice AI, dispatch, scheduling, optimization with no clean textbook answer."Jun 23, 2026Probook raised $40M from Sequoia and Andreessen Horowitz today. I joined as Founding Engineer #1 over a year ago. Two things convinced me, and both have only proven more true since. The first was the people. What I saw was a small group that outworked everyone else and genuinely cared and were passionate about the trades and about making a real impact for the people who run these businesses. I wanted to be in the trenches with them. The second was the technical problems. Home services runs on workflows that are still shockingly raw, even at the best shops in the country. Real-time voice AI, di
- Per Lewis Zhang, Yibo dropped out of college, worked at TikTok, quit after about a year, then spent time teaching kids competitive programming and rock climbing before Lewis pitched Probook; Probook's other co-founder named in team posts is Vincent Porter (CEO).Mar 25, 2026
- ICPC teammate Alex Lind later joined Probook as well (posted about joining around March 2026).Jun 23, 2026
- At TikTok (Jan 2022 - Apr 2024, Mountain View) he was on Product R&D and Infrastructure, Technical Infrastructure, US Storage team.Jan 2022
- AlphaStar Academy bio lists 1st place Stanford ProCo 2018 (Advanced) and 1st place Lockheed Martin CodeQuest 2018 (Advanced).2018
Experience
Member of Technical Staff at Cognition
Jul 2026 - Present
San Francisco, CA
Instructor at X-Camp Academy
Nov 2021 - Present
Advisor at Probook
Jul 2026 - Aug 2026
Founding Engineer #1 at Probook
Jan 2025 - Jul 2026
The AI Operating System for Home Services. Backed by Sequoia and a16z. Dispatch makes or breaks the customer experience, Probook is the only AI platform built around it. America's leading home services companies trust Probook to drive revenue growth, improve operational efficiency, and add points to their EBITDA.
Product RD and Infrastructure-Technical Infrastructures-US-Storage at TikTok
Jan 2022 - Apr 2024
Mountain View, California, United States
Instructor at Alphastar Academy
Jun 2018 - Jan 2022
100 Saratoga Ave #100, Santa Clara, CA 95051
Education
Virginia Tech
Aug 2019 - Jun 2023
Achievements2020 ACM-ICPC World Finalist (Virginia Tech, 56th) · 2018 USACO Finalist · USACO Platinum contestant 2016-2019 · 2019 Facebook Hacker Cup Round 3 · Stanford ProCo 2018 Advanced 1st place · Lockheed Martin CodeQuest 2018 Advanced 1st place · 1M+ lines of code / 1,400+ commits as Probook Founding Engineer #1
Recent posts
June 2026
Probook raised $40M from Sequoia and Andreessen Horowitz today. I joined as Founding Engineer #1 over a year ago. Two things convinced me, and both have only proven more true since. The first was the people. What I saw was a small group that outworked everyone else and genuinely cared and were passionate about the trades and about making a real impact for the people who run these businesses. I wanted to be in the trenches with them. The second was the technical problems. Home services runs on workflows that are still shockingly raw, even at the best shops in the country. Real-time voice AI, di
Press
AwardsStanford ProCo 2018 Advanced 1st place · Lockheed Martin CodeQuest 2018 Advanced 1st place · USACO Finalist 2018
Profiles
Network
ConnectionsLewis Zhang (Probook co-founder, recruited him, 15-year acquaintance) · Vincent Porter (Probook co-founder/CEO) · Alexander Lind (ICPC teammate; later Probook engineer) · Benjamin Reidys (ICPC teammate)
