Co-founder & CTO @sundayrobotics Prev 🤖 PhD @Stanford and @Columbia

Joined January 2016
25 Photos and videos
Pinned Post
From glove data to long-horizon, dexterous, precise and whole-body manipulation ⚙️ Details in this thread!
Today, we present a step-change in robotic AI @sundayrobotics. Introducing ACT-1: A frontier robot foundation model trained on zero robot data. - Ultra long-horizon tasks - Zero-shot generalization - Advanced dexterity 🧵->
18
7
122
28,692
Welcome to Sunday Junyao! MTBF going 📈
Personal update: I've joined @sundayrobotics. Two questions ran through my whole PhD: how to learn from scalable human data, and how to build general-purpose robots. Trying to answer them convinced me of one thing: general-purpose robots will never come from better models alone. It takes tight iteration across data, hardware, model, control, and evaluation. Every loop you can shorten matters. My first dinner with @tonyzzhao and @chichengcc turned into a four-hour conversation. I walked away realizing how much we saw eye to eye: scale the data, think full-stack, start from the problem you want to solve instead of the idea you want to win. So getting to work at Sunday is a dream come true, a place to solve generalization with the full breadth of human data and system-level thinking, and keep chasing the questions I care most about. After my first month in, two things stand out: Sunday’s full-stack team iterates unbelievably fast, and the energy when everyone is aligned on the same vision is electric. This speed and energy is exactly why what used to feel impossible now feels close. Home robots, the frontier physical AI in the hands of ordinary people, were long seen as a distant dream . At Sunday, I watch this dream take shape every day. I'm convinced there's real research-market fit here: foundation models and home robots point toward the same north star, generalization, not specialization, because every home is different. Excited for the zero-to-one moment ahead.
2
19
6,082
The spatial segregation of learning vs classical robotics expertise often sorts people into camps by where they went to school. But the growing intersection of the two is where the real-world performance bottleneck lives. The people who globally optimize the entire system will win in the end. Kudos to @younghyo_park and @BronarsToni for pushing past the false dichotomy that dominates academic framing.
What's different between these two BC policies? It's the same architecture, training budget, and data collection setup — the only difference is the controller gains! Controller gains are an understudied design parameter in robot learning. In our new work (w/ @BronarsToni*, @pulkitology), we show how they act as an inductive bias across BC, RL, and Sim2Real transfer, with real consequences on performance. Here's what we found 🧵 * Equal Contribution 📄arxiv: arxiv.org/abs/2604.02523 🔗website: younghyopark.me/tune-to-lear…
3
13
141
16,236
Cheng Chi reposted
If you missed @chichengcc's guest lecture on "Robotics: Beyond Algorithms" from my @ETH robot learning course, check it out on YouTube! He shares insights that are rarely taught & hard to learn in academia. 📽️ YouTube: youtu.be/tvFvIEOBKfM 📚 Course: cvg.ethz.ch/lectures/Robot-L…
10
39
276
36,347
Robotics has always been about systems all the way down! I do appreciate RSS for having the foresight of creating systems track and best systems paper awards! Proudly published all of my PhD works on @RoboticsSciSys
This is what happens when novelty, not results, becomes the North Star. The real work is often in the system details, but those rarely make it into the spotlight. Instead, we get unnecessary “novelty” that’s easier to package, pitch, and hype. Will there ever be a time when system details are treated as first-class citizens in papers?
1
4
126
12,649
Cheng Chi reposted
Excited to lead the Stanford effort on EgoVerse and share what we’ve been building 🚀 EgoVerse is a large-scale egocentric human video dataset spanning diverse scenes and tasks, enriched with text and dense hand-pose annotations, and supported by an ecosystem designed for continual growth. At Stanford, we’ve also been studying human–robot co-training behaviors across several manipulation tasks. A key takeaway: alignment matters. Strategy consistency is crucial — when human and robot data follow similar strategies, transfer improves; behavioral misalignment degrades performance. In-domain data is useful — even a small amount of target-domain human data, combined with diverse EgoVerse data, improves visual alignment between the human and robot domain and improves robot policy performance.
Introducing EgoVerse: an ecosystem for robot learning from egocentric human data. Built and tested by 4 research labs 3 industry partners, EgoVerse enables both science and scaling 1300 hrs, 240 scenes, 2000 tasks, and growing Dataset design, findings, and ecosystem 🧵
10
11
123
16,942
Excited for my talk at ETH!
Excited to welcome @chichengcc from @sundayrobotics for a Guest Spotlight at @ETH today! Who better to follow up on my lecture on generative models than the lead of Diffusion Policy & UMI? He'll cover "Robotics: Beyond Algorithms" and practical tips hard to learn in academia
3
9
135
12,985
Cheng Chi reposted
Cutemaxxing is the design brief @sundayrobotics
if your tech brand doesn't have a mascot, you're ngmi
16
16
449
31,543
Cheng Chi reposted
Growing the @sundayrobotics team in the last few months has been so exciting. New teammates every week, and contagious energy. Everyone is cooking 🔥 Processes are scaling, models are generalizing, and engineering velocity is increasing by the day. Come join us! sunday.ai/careers
We just raised $165M to end robotics demos and deploy the world's first autonomous home robots into households this year.
1
2
26
2,820
Cheng Chi reposted
Looking back to when I joined, the growth is insane. Just like weekends, time inside @sundayrobotics always moves faster. ⚡ Don't believe me? Join us and feel it yourself: sunday.ai/careers
We raised $165M at a $1.15B valuation to stop doing demos. 2026 is about 1) deployment and 2) research. We will start shipping Memo with our new frontier models in a few months. Our series-B is led by Coatue, with Thomas Laffont joining the board. ->🧵
2
3
23
5,610
Cheng Chi reposted
i met @tonyzzhao when @sundayrobotics was incubating in a silicon valley hacker house. I had zero tech or startup experience at the time, but I remember thinking... this team’s got the goods. Less than 2 years later...🚀🙏 x.com/tonyzzhao/status/20321…
We raised $165M at a $1.15B valuation to stop doing demos. 2026 is about 1) deployment and 2) research. We will start shipping Memo with our new frontier models in a few months. Our series-B is led by Coatue, with Thomas Laffont joining the board. ->🧵
2
2
20
8,475
❤️💙💚💖 @tonyzzhao
6
2
132
12,024
Cheng Chi reposted
the B in Series B stands for Beta
6
5
160
17,515
Cheng Chi reposted
As someone who has a basket of laundry piling up in the living room, I'm personally vested in seeing Sunday succeed! Excited to be a part of the team that brings Memo into real people's homes.
We just raised $165M to end robotics demos and deploy the world's first autonomous home robots into households this year.
2
1
24
5,041
Cheng Chi reposted
At @sundayrobotics we are simultaneously advancing the frontier of robot learning and bringing it to the real world! There isn’t a more exciting place to be sunday.ai/careers
We just raised $165M to end robotics demos and deploy the world's first autonomous home robots into households this year.
1
2
32
6,821
Cheng Chi reposted
So grateful I joined this talented team early on as the first SWE, when @sundayrobotics were just 3 months old at the seed stage. 🌱 Never imagined the massive progress we'd make across the entire stack—research, design & engineering. A full-stack approach from day 1 was key to our iteration speed. ⚡️ Now, I'm more excited than ever to bring the first autonomous robot to real homes this year! 🚀🤖
We raised $165M at a $1.15B valuation to stop doing demos. 2026 is about 1) deployment and 2) research. We will start shipping Memo with our new frontier models in a few months. Our series-B is led by Coatue, with Thomas Laffont joining the board. ->🧵
1
37
5,482
Cheng Chi reposted
I made the left glove with cardboard boxes in @chichengcc's apartment back in April 2024. crazy to see how much has changed since we have @clayhaight, @shyyang, Jade, and scaling the whole operations with @brainstub, @perryzjia and now the whole hardware & ops team!
In celebration of our Series B announcement today, here's what I observed as the 7th employee @sundayrobotics: 1/ Full-stack is everything. Our Memory Glove took 50 iterations from hardware to ML. Left: first prototype 2024. Right: latest gen.
5
2
99
7,902
Cheng Chi reposted
It’s incredible how much Memo has evolved in the past few months, and the best is yet to come! We’re pushing the boundaries of what our robots can do, growing our amazing team, and working really hard to bring Memo to your home this fall. The countdown is on! 👇
We raised $165M at a $1.15B valuation to stop doing demos. 2026 is about 1) deployment and 2) research. We will start shipping Memo with our new frontier models in a few months. Our series-B is led by Coatue, with Thomas Laffont joining the board. ->🧵
2
2
16
1,203
Cheng Chi reposted
Super excited to announce our 165M Series B at @sundayrobotics to help us move from demos to a shipping product. It's pretty insane the amount of progress over the last year, a year ago it was just a few people working together in a house in Mountain View. We are still hiring aggressively across a bunch of different roles, and if you've shipped hardware before we would love to meet you!
16
5
158
19,658
Cheng Chi reposted
We’re going full speed on real-world deployment! Our ML iteration loop is the most innovative and impressive I’ve seen in robot learning. Expect a lot more exciting research progress this year. Join us sunday.ai/careers
We raised $165M at a $1.15B valuation to stop doing demos. 2026 is about 1) deployment and 2) research. We will start shipping Memo with our new frontier models in a few months. Our series-B is led by Coatue, with Thomas Laffont joining the board. ->🧵
2
3
21
2,607
Cheng Chi reposted
2/ I joined summer '24 to scale data operations in a small house in mountain view. 5 of us lived in there. We all did things that don't scale: - our Head of HW @clayhaight designed and printed gloves in the home garage - our CTO @chichengcc installed a level 2 charger for all the 3D printers, built desks for employees, and did all interviews from his bedroom - our Manufacturing Engineer @che_haichuan built gloves and modified disco lights so that our (s)crappy SLAM could work in low feature environments - our Founding Designer @shyyang and I would meet craigslist strangers in the Mountain View Public Library to onboard them. We also would clean and stock the house with snacks and drinks - our CEO @tonyzzhao ran evals and desperately tried to give me crash courses on what makes data diverse and high quality. he edited tiktok style capcut videos for our data collectors and sent them encouraging feedback on their data - our Founding SWE @henry_yu_01 built all of our data review tools, constantly putting bandaids on original contractor code before we had time to kill/rebuild. he put a "do not disturb sign" on his chair as the house got more crowded
1
4
102
8,560