Saga
“What’s your story?”
A birthday, a trip, a Sunday that turned into something. Everyone who was there adds their clips, and Saga finds the moments and the chapters and edits them into one finished film. Anyone can watch with a link.
Engineer · Filmmaker · Tinkerer
Building things. Collecting stories. Figuring out life.
I’m Jacky. In third grade I decided I would become an inventor; it took me a few years to learn the job title is “engineer.” I’ve been making videos for about as long. Right now I’m building Saga, an AI director that turns everyone’s footage from a shared day into one film. Before that, I spent four years at Amazon building AI systems for messy, real-world documents.
Now
Things I’ve made
Software, films, hardware, and a few experiments.
- NowSagaApp · AI ↗An AI director for shared experiences. Multi-model agent graphs handle multimodal analysis, transcription, moment selection, edit planning and rendering.
- NowLED pieces, including a heart you can climbHardware · Art ↓A few wiring-heavy light pieces. The interactive one is a walk-in wooden heart, built with Moon Landing Camp and outlined in addressable LEDs: touch it and the light charges, glows and starts to beat. Photos, a bench test, and a simulation below.
- 2026Saga Eval LabResearch toolTools for labeling footage, reviewing outputs and comparing models on creative-judgment rubrics, negative results included.
- 2026Fleet-OSOpen source ↗A multi-agent coding runtime: persistent task coordination, isolated worktrees, resumable workers, cost tracking, and evidence checks before anything counts as done.
- 2022–26Document AI at AmazonSoftwareTech lead for a multi-tenant, self-service document-processing service: OCR, LLMs, agents, and an evaluation framework that improves with human feedback.
- 2019–21Sonder SocialAppAn app that nudges and facilitates thoughtful interactions. I led a small team from first commit through alpha and open beta.
- —A DIY electric bikeHardwareBuilt from parts.
- 2014||PAUSE: EngineeringShort film ↓My entry for the National Academy of Engineering’s E4U video contest.
- 2013My first HackintoshHardware ↗An i7 tower built from parts. In the words of 2013 me: “This took forever to troubleshoot.”
- HSA camera capsule in near-spaceHardware →Two cameras, one weather balloon, and a senior year spent breaking an “unbreakable law.”
- 2009–10Media Productions filmsFilm ↓Early videos from the high school club I founded, plus a Harry Potter spoof.
Press & hold
IdleCharge 0%
The light
Hold the heart.
I’ve built a few LED pieces. This is the interactive one: a heart big enough to climb, built with Moon Landing Camp, outlined in addressable LEDs, with a touch sensor. Left alone, it twinkles through the rainbow. Touch it and a warm charge climbs from the tip of the heart to the top. Keep holding on and it starts to beat. Let go, and it drains away.
- IdleRainbow twinkle
- ChargingWarm light climbs the heart
- FullA red heartbeat
- ReleaseThe charge drains back down
This is a simplified browser re-creation of the piece’s behavior with 300 LEDs, debounce included: a touch only counts after it’s been steady for a moment.
The real thing
Films
Before Saga, there were these.
I’ve been making videos since grade school. A few survive on the ChenBrothers YouTube channel.
Out in the world
Mountains, and the occasional glowing bike.
What I’m into
What I think about when no one’s asking.
AI safety & an abundant future for all
Thinking about how we navigate to an abundant future for everyone, not just a few. I study interpretability, red-teaming and evals, and the practical bottlenecks: compute, energy, data, and whether we actually understand what we’re building. At USC I wrote a paper on nuclear safety, and a lot of the same questions apply.
Storytelling & memory
I’ve been making videos since grade school, and now I build software that edits them. The question underneath both is the same: what makes a moment worth remembering, and to whom?
The Chinese diaspora
Both of my parents came to the US as teenage immigrants with very little and each started their own business. I’m interested in the stories of families like ours, including my own.
Photography
Candid moments and good light, on a Sony mirrorless.
Things that light up
LEDs, sensors, an e-bike, and whatever’s next on the bench.
Healthspan & longevity
Small changes, applied consistently, observed patiently. I learned that from my house plants. I wrote about it.
Physics & energy
Nuclear safety and the energy problem, since my USC days.
Travel & languages
About twenty countries so far. Working on Mandarin and Spanish.
Cooking & hosting
Long dinners, game nights, and bringing people together.
Moving
Kitesurfing, cycling, and dancing. I breakdanced in high school.
Burning Man
Went for the first time in 2026, with Moon Landing Camp.
Puzzles
A daily sudoku habit, so I built one. Play today’s.
Principles
How I see and approach life and the world.
First principles thinking
Understanding the foundations on top of which assumptions are made is important for approaching anything in life. Without direction, our actions could even be harmful rather than helpful. Think before acting.
Stoicism & openness
We are in control of our destiny. Our lives are filled with decisions that we can either make thoughtfully, or go along with, without ownership of it. Bad things happen. Own how we respond to and grow from them.
Humility & awareness: sonder
Everyone is living a complex life with their own set of challenges and goals. Respect that. Assume better of people even when we don’t believe they deserve it.
Written for the first version of this site (2017–2021). See it preserved →
From the archive
For the first time in my life, I had truly given myself permission to be extraordinary.
Daily Sudoku
Today’s puzzle
A new grid every day, the same one for everyone.
Writing
The Timeskip
My personal Substack. Latest: “What Aging Means to Me: Thoughts from Refocusing in My Thirties.”