Why do the best conversations at a conference happen after hours?
I created The Ruby Underground for thoughtbot, an invite-only night in a secret location for the people shaping Ruby and Rails.
In Philadelphia, we met in an old bank vault. The conference had wrapped for the day. The talks were over, the hallways were emptying, and most people were heading to dinner or back to their hotels. A smaller group was heading somewhere else. They had an invitation, and an address almost nobody else had.
It’s hard to think of a better place for a secret than a room that was built to keep things safe.
Inside were authors, keynote speakers, CTOs, open source and core contributors. The people who built much of what the Ruby and Rails community uses every day, and the people shaping what those tools become in the AI age. Between 50 and 100 of them in one room, with cocktails, hors d’oeuvres and nowhere else to be.
That’s The Ruby Underground. I created it for thoughtbot in 2024, and I’ve hosted and produced every one since. It’s become the most sought-after ticket for some of the most influential people in our industry, and it happens after hours, in a place you’d never find on your own.
What a conference can’t do
Conferences are great. They’re where a community gathers, where people share what they’ve learned, and where you catch up with friends you only see a few times a year.
They aren’t the right venue for everything, though. They aren’t built for tastemaking, for working through a new idea with someone who really gets it, or for making a strong new connection with the person you’ve admired from a distance for years. Those conversations need a different kind of room. Somewhere unique, and without distractions.
So I decided to make that room, and to make it part of the conference week, in the hours after the official program ends.
Invite only
The Ruby Underground is invite only. There’s a waitlist, and the location stays a secret.
How the guest list comes together is the part I keep to myself. What I’ll say is that in every city, I find the most influential people in technology there and make sure they come. And the list is always curated, so that everyone in the room has a unique story and ideas to share.
We keep it between 50 and 100 people. That’s on purpose. Everyone should get a chance to meet everyone else, and past a certain size, that stops happening.
Finding the room
The first one was in Detroit in 2024, during a Ruby conference there.
Since then we’ve taken it to Chicago, Philadelphia, Las Vegas and Austin, always in the after hours of a major Ruby or Rails conference.
The room matters as much as the guest list. In Chicago, we met in an underground speakeasy in an old fire station. In Philadelphia, it was the bank vault. Each place has a history, and each one feels like somewhere you’re lucky to be.
In Las Vegas and Austin, the goal was the same. Find a room with a story, somewhere most people in town would never think to look, and make it ours for one night.
How the night works
Once people are inside, the night is about conversation. There are hors d’oeuvres and custom cocktails we come up with for each event, and the music is chosen as carefully as anything else.
There’s always a social game, created and curated by thoughtbot, with prizes for the winners. It gives people a reason to find each other, and a reason to talk to someone they might not have walked up to on their own.
Everything about the evening is curated, from the agenda to the drinks. None of it is there to show off. It’s there so that people relax, open up and stay longer than they planned to.
What happens in the room
The best part of hosting is hearing what happened afterward.
One year, a keynote speaker came. Nobody would have guessed they were open to a new job. They met the right people that night, and not long after, they were recruited away to join another company.
Another night, two developers who had known of each other for years met in person for the first time. They left as business partners.
Those are two stories. There are more. Deals have come out of these nights. People have been hired. Companies have been founded, books have been written and podcasts have been arranged, all from conversations that started in a vault or a speakeasy or a room most of the city doesn’t know exists.
For thoughtbot, it means staying close to the people who are shaping our industry. That’s hard to do from a booth on an expo floor. It’s a lot easier over a good cocktail, with the right people, in the right room.
Taste matters
If I had to explain The Ruby Underground in two words, it would be those.
Taste in where we meet. Taste in the cocktails we come up with. Taste in who gets invited. Taste in the music that’s playing. Taste in how the night’s agenda comes together.
Any one of those on its own is a small decision. Together they decide whether a night is forgettable or whether people are still talking about it at the next conference.
AI is making it easier than ever to make things. As making gets easier, taste and judgment matter more, and that’s as true for a night like this as it is for software. Anyone can book a room and order drinks. Deciding which room, which drinks and which people is the work.
I think that’s why these nights keep working. The people on the guest list spend their days making choices that shape how thousands of developers work. They notice when someone has made careful choices for them. And when they feel that care, they bring their best ideas into the room.