Travel Log: Heart of Clojure 2024

When Heart of Clojure was announced earlier this year, I hesitated. I had heard the name before, and I had heard praise of the last instalment 5 years ago. One of the reasons I wasn't sure whether I should go was certainly cost, but that wasn't the main one. The main reason was anxiety. A fear of being an outsider to a group of people who already knew each other and being left to myself as a result. This wasn't particularly rational of me. Throughout the last 2 years, my introvert brain created those same "oh I don't think you'll have a good time there"-doubts for all of the decisions that led to some of the best and most memorable experiences of my life.

So this time (and for the future), I decided to drastically simplify my decision making process for whenever I'm contemplating whether to go somewhere or not for fun. I boiled it down to a single question: "Am I going to regret doing this?" For Heart of Clojure, I figured the answer to that question was "most likely not". So I thought what the hell and bought a ticket.

School trip vibes

I think the last time I slept in a hostel dorm was in 5th grade on a school trip somewhere. Unfortunately, I'm not particularly good at falling asleep¹, which made me worried I'd be completely sleep-deprived for 3 days. Why even choose to share a room with strangers then? Well, mostly because it's cheap, but also because I've met many other people doing short-term solo travels and staying in hostels, and it seemed like they were socialising a lot more than the hotel people. In any case, as it turned out, I did fine in terms of sleep. I did not sleep well, but I wasn't barely clinging to life in the mornings either. In fact, after the first and worst night (where I felt like I barely slept at all), I strangely didn't feel tired at all throughout the entire day.

One thing I didn't think about at all before was that sleeping in a room with 5 strangers means making a lot of compromises. People go to sleep and have to get up at different times, have different routines in the evening and morning. I was lucky with my roommates in that regard, because everyone was really careful to avoid disturbances as much as possible, e.g. when coming home at night while others were already asleep. I also didn't have to fight to get access to the shower in the mornings, which was good.

I think I'm going to stay at more hostels in my future solo travels. The savings on cost, the included breakfast and the potential to meet new people probably outweigh the inconveniences most of the time for me.

So many people

Heart of Clojure wasn't a very big conference in terms of number of attendees (around 300, I think?), but it was truly a people's conference. The talks were good, too – but the main attraction for me was certainly getting to know so many awesome humans.

One problem when going to an event where you don't know anyone is making that first step, walking up to people and striking up conversations. If you don't do that, then you'll just stand around in some corner and feel awkward. For some people, this hurdle is a lot easier to overcome than for others. For me, it's pretty difficult unless there's something concrete for me to jump in with.

Two things I did helped a bit with this initial personal barrier at Heart of Clojure. First, I was in contact with some of the organisers from pretty early on because I did some work on the in-house attendee website², so my name was recognised a couple times and there was a conversation starter. The other thing was organising a late dinner the night before the first day. I met some people there whom I hung out with a lot over the course of the conference, and there were some familiar faces on the first day.

My favourite experiences

Here are some of the things that happened at Heart of Clojure that I truly enjoyed.

Heart of Clojure happened at two different locations separated by a straight, 7-ish minutes walk. One was Het Depot, an old cinema (used for the main talks), and the other was Hal 5, a sort of warehouse with lots of room and custom conference setup. I didn't like Het Depot that much as a location, since the space outside the main room was quite narrow, and the presentation room was a bit too dark and gloomy for my liking (both of these issues were counteracted by there being a big square right outside). I loved Hal 5 though – the different table arrangements, the workshop area, the sunny lawn outside, the coffee, everything.

What I particularly liked was this inbetween of locations. You could have a relaxing walk by yourself, meet someone new on the way (Hi Martin!), or chat with previous acquaintances some more. My hostel was right in the middle between the two locations too, which was super convenient.

Leuven, as a city, felt like the perfect place for a conference. Completely walkable, great food, cosy but full of life. Originally I had planned to visit the campus of KU Leuven — the biggest university there and a pretty well-known one in computer science — in my quest to find a suitable uni for the future of my studies. The timing didn't work out though unfortunately, so I guess I'll visit the city again at another time (not that I mind 🙂).

Lu's (aka TodePond) keynote "What it means to be open" was very very good. You should watch it once it goes up online. I've been a fan of their work for a while, so I was happy when they were announced as a speaker. I was nervous talking to them at first, but they were the nicest person! We talked a couple times over the 2 days and I got some interesting insights into how they do what they do.

The catered lunch (falafel, hummus, sarma, salad, bread) was delicious and plentiful on both days, and also a great time for talking to other people. On the first day, I randomly recognised Vladimir aka farcaller sitting next to me because I'd seen his talk about Nix and Kubernetes last year. I also met Danjela and we talked about plans for the future and landing a job in Clojure.

I hung out with Miranda aka pulu a lot during the conference, and we had lots of great conversations. She played a livecoding set the night of the first day which was really cool to experience (I had never seen a livecoding music performance before). Also, the setup for her music making is genuinely insane (in a good and fun way). As someone else put it, it's the embodiment of the hacking mindset: make things work together that shouldn't work together, for no particular reason. Generally, I learned a whole lot about electronic music and livecoding, which I didn't expect coming to the conference.

Lovro's and Sung's presentation "Klor: choreographic programming in Clojure" was really interesting and super well done, my favourite out of all the Clojure-related talks. Sung made amazing slides using LaTeX Beamer, of all things, and the presentation was engaging, fun, and just the right level of technical. I loved how this was a bridge between something really academic (choreographic programming as an active field of research) and something concrete for people to put their hands on (klor).

The introduction to application.garden workshop didn't really get as deep into the tooling as I'd hoped, but it inspired me to hack on something again. application.garden is a fantastic idea to make it easy for people to get things done with Clojure, but I dislike that the backend is not open source, so the last couple of days I've started working on an alternative implementation. Let's see where this goes.

One of the cool things about Compass, the attendee website for Heart of Clojure, is that its schedule was built to be open to everyone. Anyone could create their own little activities or workshops there, and other people could press join and show up. One of these activities was created by Matthias, who wanted to learn how to use lsp4clj for a personal project. We ended up chatting, learning about lsp together and coming up with ideas for projects involving it.

The lightning talks segment right at the end of the conference was awesome, and I loved seeing people get up on the stage with completely different topics, styles of presentations and levels of preparation. Here are my favourites (I hear this will also be put online):

• "how a pile of hacks becomes an instrument" – Miranda explaining her cursed livecoding setup
• "Lossy CSS compression for fun and loss (or profit)" by Daniel, who started it by saying "Let's lossily compress some CSS!", which was pretty funny by itself. But the rest was a perfect balance of the technical curiosity of a nerd who got sniped, utter obscurity and silliness, as well as a genuinely interesting result showcase!
• "You should write a blog post" by Miikka, telling everyone to write a blog post about Heart of Clojure. Well, here we are!

I really enjoyed going out to dinner with other people on all three evenings:

• fantastic vegan curry at Het Strand, where I also first met Miranda, Lovro, Jakub and Gleb.
• great vegan East Asian fusion cuisine at BODHI, with Ben, Karlis and Bart
• decent burgers at Ellis, with Miranda and Lovro. Also, I briefly met Jeaye there, whose blog about jank, their C++-based Clojure dialect, I've been reading for a while now.

I had so much fun on the last evening when what felt like the entire conference went out for drinks in the centre of Leuven:

• lots of chatting with Miranda, Carmen and Leah (after which my vocal chords were truly fried)
• bonding with Felipe over our shared love of linguistics
• getting to know Dave who was probably the most outgoing person I met at the conference. One of the stories he told that night made me cry from laughing. He also invited me to submit something to the Clojure Berlin meetup (which I feel like I have to do now!)
• talking briefly to James Reeves aka weavejester who is the man behind many Clojure libraries I use all the time.

Staying a bit longer on Friday, the day after the conference, was a good decision. I got to know Tinko a bit more, whom I shared a hostel room with and who was at the conference as a volunteer, as we walked around Leuven and spent some time at its botanical garden. He was also one of the few people my age there (one of the others I met was Olav), which made it a bit easier to connect.

For lunch I met up with Lovro and Jakub (a nice callback to the first dinner), had a pretty bad Lasagna (😐🤌) and then went off to explore the city some more with Lovro. Honestly though, I wasn't so much focused on the areas we visited, since we got into some really interesting technical conversations about the projects we have worked on.

When we were back in the centre at a café, I teamed up with Felipe to go to the station to catch an earlier train and we travelled to Cologne together, where our paths then split. It was really nice to have him as a travel companion, and again, like the night before, we made some really good conversation.

This was great

I made lots of memories at Heart of Clojure, and my decision to go there was probably one of the best ones I've made in recent years. It was the first tech conference I ever attended, and I think it turned out to be the best experience I could have possibly had for this occasion. I learned, I laughed, I got inspired, and thinking back about it now already makes me a little emotional. I hope that this conference will happen again in the future, and that I meet all the lovely people I've met there again somewhere else before that. On that note, anyone from the conference, especially if we didn't exchange contacts, feel free to hit me up!

I want to close this by pointing you to other posts about Heart of Clojure. If you make one, let me know in the comments and I'll add it!

• Things I liked about Heart of Clojure by Lu
• Scrappy hearts and Clojure fiddles by Manuel
• Heart of Clojure retrospective by Vladimir
• Heart of Clojure 2024 (It's okay) by Daniel
• People of Heart of Clojure - The Unofficial Hallway Track 2024 by Toni
• Weeknote 6: Heart of Clojure by Miikka