About

I’m James Dennis. I transform ideas into tangible things, whether software, music, or writing. I’m happiest when I’m building something new or learning something deeply.

Work

I’ve worked across the stack, usually building backends, infrastructure, and ML pipelines, and the occasional frontend or mobile app. Currently, I choose to work in Python and Rust, but I’m an easy going polyglot. I love transforming ideas into working systems quickly, with small teams or established organizations.

I built data pipelines & backends for Spotify, a payments gateway and deployment tooling for Venmo, and ML pipelines that processed hundreds of terabytes of video for HBOMax. I developed a mobile player for VHX (acquired by Vimeo) and an event admission system for The Whitney Museum’s biennial. While doing DARPA funded mental health research with Qntfy, I designed and built out a data collection system that could scale linearly while collecting data from every major social network and fitness tracker. At UPenn, I contributed to the design of their new AI degree programs, built AI tools to support students and professors, helped construct Coursera lessons, and published research with Chris Callison-Burch.

Through J2 Labs, my former consultancy, I built many backends and infrastructures for numerous smaller companies, some acquired, others that ran their course as early stage companies do.

My open source creations include Schematics (a type system for Python focused on human data types), Brubeck (a concurrent server framework), and Micro Army (a distributed load testing tool). I’m currently rewriting Micro Army in Rust as Killa Beez. Users of my open source projects include Apple, Huffington Post, Warby Parker, and Criterion Collection.

I co-founded several tech communities including Hack && Tell, Brooklyn Swift, and Dumbo Tech Breakfast. I studied computer science at Northeastern University and I was in the first batch at Recurse Center.

Music

I first picked up a guitar around 11, had my first band a couple years later, made a few records before finishing high school, and soon enough, I was in a van touring the US & Canada. I’ve had several bands since then, written a lot of music, and I still play live. I haven’t toured in years, though.

Check out the music section for stories about each project, with music, pictures, and videos.

History

I’ve been reading history since 2012. I explain how that happened in this post.

I’m drawn to moments where historical figures designed memorable ways to communicate their ideas. Leonardo da Vinci, Samuel Adams, and Eleanor Roosevelt are favorites. For them, it wasn’t enough to get their point across. They wanted history to remember their message too.

I feel strongly that history is important, but I also recognize it doesn’t appeal to everyone, so I make it more fun by writing about it the way I talk about it to my friends, with plenty of memes, pop culture references, and a hearty appreciation for the noble rascals.

Contact

You can always find me at this website because I intend to keep this URL for the rest of my life. It’s my name, without the vowels, dot com.