We built our own IDE 

Actually, we didn't build an IDE. We built a “work dashboard” in quotes. We built a multitasking terminal app? A runtime for our agents? We built our own cmux or Herdr? What is it? Read on to find out.

Be me in 2025.

Engineer: “Hey, Paul, I think we should form a team to build an internal IDE with all of our system knowledge built in to help engineers move faster.”

Me: “Get out of my office.” (I work in my garage btw.)

If someone had asked me in 2026, I probably would’ve still said no. But this time, nobody asked me. The team could not be denied, they built it, and it’s pretty great! We call it Tower.

Tower is no one's full-time job. It's a labor of love created by and for our engineers so they could work more effectively. It is a chance to learn, do research, play with the state of the art and use the latest AI tools. It's what happens when you have a team full of folks with high agency who understand that “you can just do things.”

We don't have a huge team, and our team is very busy. Customer.io (http://Customer.io) is under 400 people today, with fewer than 100 engineers serving over 11,000 customers, so nearly all of our time goes to building for them. We’re focused on making our customers’ businesses wildly successful, and we know we have a lot more to do. Tower got built in the margins to give us more time for that work.

It wasn't only engineers. Our CEO, Colin, has merged 41 pull requests in our tower repo. Who is going to tell him “no, you can’t add Linux support”? Nobody is going to tell him that.

Tower is our own work dashboard: a workspace (what we'd have called an IDE in 2025). It's where our engineers run and interact with their AI coding agents.

Each piece of work gets its own space, with its terminals, its pull requests, its deploys, and a notepad that both the engineer and their agents write in. Agents keep running when the window closes, and Tower tells you when one finishes or needs an answer. Everything else plugs in as an extension (37 so far), including four desktop pets you feed by merging PRs, because we strive for levity.

• Early September: Super Engineer 1 builds a small dashboard to keep track of their agents. It was called Tower "because it was just for me initially." (We don’t get that reasoning either.)
• September 12: It becomes a company repo. The first pull request brings in 159 commits they’d already written.
• September 18–21: Super Engineer 1 and 2 rebuild it as a native app in about three days.
• September 21: It gets its own Slack channel, and our CEO, Colin Nederkoorn, opens his first pull request that same day. Three days later he ships nightly builds with an auto-updater.
• Since then: 22 people have merged 781 pull requests, about 15 a day. Everyone ships their dreams and fixes what annoys them. That has meant themes, dictation, a markdown editor, deploy tracking, a 1,000× faster terminal paint, an iPhone app, and, finally for the green bubble people, an Android app from an engineer who decided we must have one.

Our ultimate goal is to build products and features that bring our customers value: things that make their lives easier and take on the pain and drudgery of getting their work done in our platform. Tower speeds up our ability to do that.

It also fits our practical approach: we do what works. We don't let ideals, best practices, or what other folks are doing get in the way of what we think of as pragmatic for us. The question is always the same: what can we do to make our work easier? This time the answer was building our own IDE agent workspace.

Will better tools come out of the industry? Maybe.

Will we grow to hate Tower over time? Also maybe.

Tower is an accelerant for now. We're doing what works today, and as new techniques emerge, we'll integrate them (steal them), or adapt and move on to new tools.

That approach is the real story here, more than Tower itself.

Next, we want to free people from the shackles of their laptops. Tower can already run work on other machines, and the iPhone and Android apps connect to it from anywhere. We're working toward agents running in cloud dev environments, so you can kick off work, close the lid, go for a walk, and steer it all from your phone. This is not a 3 month roadmap, this is next week’s plan.

If this kind of work is interesting to you, being at the forefront of AI tool development and figuring out how to make an already prolific engineering team even more prolific, this might be a good place for you to work. Check out our Engineering Openings.