Constants x Party: Holiday Mixer & Build Night
Join Constants and Party on Saturday, December 5 for a hands-on build night at 810 Hamilton in downtown Redwood City.
We’re bringing together product people, founders, engineers, designers, and builders for a friendly holiday challenge. In teams of 3–4, you’ll use Party to build a small online gift shop from the same brief. Then we’ll put every shop through the same shopping tasks with Constants’ simulated shoppers.
You’ll also try the other teams’ shops and rate them using the same criteria. We’ll compare human and simulated feedback, see where they agree and disagree, and crown the shop shoppers rate highest.
No prior experience with Party or coding agents is required. Bring your laptop, your ideas, and a little competitive spirit. Food and drinks are on us.
What you’ll do
Get a quick introduction to Party and Constants.
Form a team of 3–4 and create your own Party space.
Build a holiday gift shop together, with agents helping bring your ideas to life.
Watch Constants’ simulated shoppers tackle tasks like finding a gift for a coworker under $40 and checking out.
Try other teams’ shops, compare feedback, and connect with fellow builders.
What to Expect
Schedule is approximate.
5:15 PM | Doors, Food & Networking
Check in, grab food and a drink, and meet the other builders.6:00 PM | Welcome & Product Intros
Meet Party and Constants and get the challenge brief.6:20 PM | Holiday Build-Off
Build your team’s shop, then put every shop to the test with simulated shoppers and fellow participants.7:20 PM | Feedback & Winner Reveal
Compare human and simulated feedback and find out which shop comes out on top.7:30 PM | Open Networking
Swap ideas, talk through what you learned, and meet the teams.8:30 PM | Wrap Up
Who Should Attend
Product managers and growth managers exploring new ways to build and gather feedback
Founders, solo entrepreneurs, and startup leads
Engineers, designers, and anyone building products with AI
Anyone curious about collaborative building and simulated user testing
All experience levels are welcome.
What You’ll Walk Away With
A working holiday gift shop you helped build
Hands-on experience building with a team and agents in Party
A comparison of participant feedback and Constants’ simulated shopper feedback
New connections with people building products with AI
Important Details
Format: In person, with teams of 3–4
What to bring: Your laptop
Experience level: All levels; no prior Party or Constants experience required
Registration: Please RSVP in advance
Event Info
🎟️ Registration: RSVP required - capacity is capped at 50
🍽️ Food & Drinks: Provided
🏢 Venue: 810 Hamilton - our event space in downtown Redwood City
📍 Address: 810 Hamilton St, Redwood City, CA 94063
🚗 Parking: Street parking on the surrounding blocks & parking structure on Jefferson St.
🚉 Transit: One block from the Redwood City Caltrain station. Approximately 25 min Caltrain ride from 4th & King.
About Party
Party is the multiplayer workspace where your whole team builds together alongside fleets of agents, out in the open. Agent Flows do the heavy lifting while humans steer. You pick the harness and model for each agent in the Flow - Claude Code, Codex, Cursor, Opencode - and work in the same secure session as the rest of your team. Bring your own keys, or use ours.
Learn more about Party at party.build. Try Party at app.party.build (web, MacOS, iOS, and Android).
About Constants
Guessing costs users and revenue. Constants helps product and growth teams find, interview and digital twin their target users to figure out what’s working, where people get stuck, and which idea to ship next. Connect our tool suite to your agent and turn feedback into shipped improvements, fast.
Learn more at constants.io.
About 810 Hamilton
810 Hamilton is our event space in downtown Redwood City - a converted loft in the heart of Redwood City. It's where we host Build Nights, and it's available for other events too. 810hamilton.com
Sponsorship & Partners
Interested in getting involved? We work with partners on demos, speaking slots, and co-hosted nights. Reach out to Julian at julian@810hamilton.com