Building in public

Mastermind sessions, in writing.

Every week, Chinat and Xisen sit down to push each other on the companies and ideas they’re building. Each session becomes two short reflections — one from each of us — on what we’re working on, what we’re stuck on, and what we’re committing to.

• July 27, 2026Chinat

  Distribution, Not Teachers

  Hiring teachers changed nothing about the education business; the scarce asset is a channel I own.

• July 27, 2026Xisen

  Calendars Are Connectors Now

  Demoting our own top-level features told us what Aicoo actually is: an agent-to-agent collaboration layer.

• July 24, 2026Chinat

  The Refusal

  An AI broke out of its test to cheat. What cleaned up the mess was an open model anyone can run — and the lesson isn't US versus China, it's how we build the next one together.

• July 15, 2026Chinat

  Buckets and Taps

  Nobody pays a water bill for a reservoir. The full frame for where AI value gets captured: the bucket that catches asymmetric data, and the tap that squeezes it and pours it out as gold.

• July 14, 2026Chinat

  The Future Unfolds: My Notes from Bank of Singapore's CIO Summit 2026

  A builder's day among the capital: the five supertrends, Howard Marks on why the worst loans are made in the best of times, and a closing panel that reframed US-China as fewer illusions, more stability.

• July 14, 2026Chinat

  SpaceX, the East India Company, and Hong Kong's Next Chapter

  The densest hour of ideas I've heard this year: Tao Dong on stock-market capitalism, the orbital land grab, forgetting the past China, and why the Hang Seng became a food-delivery index. What it all means for builders.

• June 25, 2026Chinat

  Johns Hopkins Is a 150-Year-Old Startup

  I went to my university's 150th birthday party expecting nostalgia. Two historians on stage described the founding, and halfway through I realized they were describing a startup that almost died of its own ambition, several times, and kept going anyway.

• June 16, 2026Chinat

  Nordstrom Was a Failed Prospector

  Most of the people who ran to the Klondike came back broke. The ones who got really rich did not prospect at all. They built the hotel.

• May 31, 2026Chinat

  Same Week, Different Bet

  Xisen has been running Aicoo for over a month. I shipped Beeper v1 this afternoon. On today's call we discovered we had built versions of the same product from opposite ends of the stack. When two people you trust converge on the same problem, the wave is here.

• May 31, 2026Chinat

  Talking to Computers in Public

  Voice is becoming the dominant way we talk to AI. Cafes are the dominant place we work. Those two things are incompatible right now. The fix is a mask that eats your voice on the way out.

• May 31, 2026Xisen

  A Contact Book for Agents

  Aicoo is a contact book for agents, not a chat app. Chinat shipped a parallel bet on top of iMessage. The disagreement is where the policy layer lives. The bet is that the agent, not the chat, is the actual product.

• May 24, 2026Chinat

  Buckets for Rainwater

  Hyperscalers won by building the biggest bucket. The next wave wins by placing the bucket where the snowmelt is — asymmetric data, fresh at the source.

• May 22, 2026Chinat

  Mics in Every Room

  Revenue is downstream. The real north star is whether you're collecting data nobody else has.

• May 10, 2026Chinat

  Public Likes, Private Bookmarks

  Demo Day Connect ran for six hours, hit a thousand users, and surfaced an asymmetry between public likes and private bookmarks that no async product can show you cleanly. Live events are an undervalued software leverage point.

• May 10, 2026Xisen

  Agent Said No, Then Said Yes

  Frontier models refuse privacy violations on the first attempt and cave at 2.5x the rate by the fifth. Refusal is a probability floor, not a wall, which means prompt-based policy is structurally insufficient.

• May 4, 2026Chinat

  The three-hour rule

  Cover your week with three hours of paid work, then spend the other one hundred and sixty-five compounding.

• April 20, 2026Chinat

  Two Hackathons in Two Days

  Running back-to-back hackathons at Cornell and Hopkins revealed the difference between a show that needs a showrunner and a machine that needs an operator.

• April 20, 2026Xisen

  Three Thousand Adversarial Tests

  Running 3,000 agent-to-agent security benchmarks revealed the contact security paradox. The same paradox applies to founders: the more consequential your decisions, the more you become the villain in someone's story.

• April 12, 2026Chinat

  Everything is a CLI now

  The shape of every partnership we're signing this quarter is a skill install, not a contract. That's a bigger change than it sounds.

• April 12, 2026Xisen

  The word we keep coming back to is "networking"

  Pulse opened its API this week. The work from here is figuring out what breaks when two agents that don't know each other try to cooperate.

• March 14, 2026Chinat

  The pipeline is starting to be legible

  Demo Day for intake, the Hong Kong flagship for distribution, MentorMates underneath. I'm finally starting to see the shape.

• March 14, 2026Xisen

  What to benchmark when your users are agents

  Pulse security stopped being a concept and started being a benchmark. That changes what the product has to prove.

• March 9, 2026Chinat

  The flagship is the hackathon, not the product launch

  Hong Kong is the operating thread this quarter. Everything else feeds into it.

• March 9, 2026Xisen

  Why I stopped building an outreach tool

  Outreach automation is the wrong shape of problem. The real work is agent-to-agent memory and access.

• February 28, 2026Chinat

  From a YC hackathon floor to a Hong Kong flagship

  I'm on the floor of a YC hackathon this weekend. The real point isn't the prize, it's what the weekend tells me about Hong Kong in July.

• February 28, 2026Xisen

  Narrowing Pulse to the founder use case

  The Pulse pivot is still narrowing. Founders are the sharpest user, and two specific jobs do most of the work.

• February 14, 2026Chinat

  The Stanford hackathon changed what I thought I was building

  A thousand hackers, three days, and one reframe. MentorMates is a platform question, not a feature question.

• February 14, 2026Xisen

  Two features, done better than anyone

  I was chasing differentiation on surface area. The better bet is depth on one or two capabilities.

• February 7, 2026Chinat

  Partnerships are distribution, not decorations

  We shipped the first real agentic layer in MentorMates this week. The lesson: partnerships are only useful when they convert to reach.

• February 7, 2026Xisen

  User interviews and API-shaped thinking

  Two moves that pulled Pulse forward this week: more user interviews, and starting to think about it as an API instead of an app.

• February 3, 2026Chinat

  Hackathon week is the real test

  Two hackathons in one week at Johns Hopkins and Stanford. Distribution showed up. Team reliability didn't.

• February 3, 2026Xisen

  Heartbeats, active layers, and better testing discipline

  Pulse got a heartbeat and an active layer this week. The bigger win was pulling the team into better testing discipline.

• January 24, 2026Chinat

  Daydreamers Academy and hackathons are the same thing

  Sounds like two different products. They're not. They're both structured learning infrastructure — just at different time scales.

• January 24, 2026Xisen

  The research direction has to be chosen, not discovered

  After too many parallel threads I realized the research question doesn't get picked by the field. It gets picked by me.

• January 17, 2026Chinat

  MentorMates is the center of gravity

  A Q1 planning call forced a real choice. Multiple good options, but only one center of gravity. MentorMates wins.

• January 17, 2026Xisen

  Writing the paper is the discipline

  Drafting a paper is a forcing function. You can't hide scope creep when you have to write it down.