Follow the Backpacks: A First-Timer’s Guide to FOSDEM

If you haven’t heard of FOSDEM, imagine 8,000 open-source enthusiasts descending on a university campus in Brussels for a weekend. There are no tickets, no sponsors dictating the agenda and no one telling you where to be. It is one of the largest gatherings of software developers in the world, built and run entirely by volunteers.

The Atmosphere Starts Early

The shift begins Friday evening. Brussels starts to transform. You see them everywhere: the backpacks, the laptops, the slightly sleep-deprived eyes of people wandering the streets, torn between finding their hotel and finding a spot for a Belgian beer. By Friday night, the “FOSDEM spirit” is already thick in the air.

Then comes Saturday morning, which offered me my favorite piece of advice:

If you step out of your hotel and see a crowd of slightly eccentric people with backpacks moving in one direction — just follow them. Trust the crowd more than your GPS. The crowd knows where the code is.

How Not to Drown

FOSDEM is overwhelming by design. Dozens of tracks running in parallel, hundreds of talks, and a constant flow of people. You will get lost — sometimes mentally inside a deep-dive talk, sometimes physically in the maze of the ULB campus.

That chaos isn’t a bug. It’s the feature.

A few survival tips I wish I’d known earlier:

• Pick one track. Max two. Leave space for hallway conversations — they often matter more than the talks themselves.
• Say yes to spontaneous discussions. You never know which BOF you’ll end up in. These aren’t formal talks; they’re unconference-style rooms where you stop being an audience member and start actually solving things with other people.
• Plan your lunch conversations. Time disappears incredibly fast, and forgetting to eat or drink is easier than it sounds.
• Use visible team identifiers. Hats, t-shirts, funny accessories — they help you find your people and make it much easier to start conversations with strangers. The guys in the traffic cone hats had the right idea: in a packed corridor, a bright orange cone is more useful than a map

Reality Checks (a.k.a. Logistics)

On FOSDEM morning, trying to get on public transport towards ULB after Gare Centrale is… an experience. Don’t expect to get on the first bus you see. Packed vehicles, dense crowds, and very little personal space are all part of the deal — completely expected for that day.

The campus Wi-Fi won’t survive — that becomes obvious quickly. What’s less obvious is that mobile networks also barely work, simply due to the density of people. Save the schedule offline on your phone in advance. It really helps.

On the way back, I strongly recommend walking. Take the scenic route through Ixelles, passing the Étangs d’Ixelles. It’s downhill all the way, and after a long day of technical overload, it turns into the perfect decompression walk back toward the city.

Depth Beats Coverage

Spending most of the day in a single devroom — for me, the Browser and Web Platform track — turned out to be the right call.

Staying in one place changes how the conference feels. Conversations get longer. Context accumulates. You stop optimizing for “what else can I catch” and start actually listening, thinking, and recognizing familiar faces. It’s a very different experience from running between buildings trying to maximize coverage.

FOSDEM quietly rewards this kind of focus.

Why This Format Works

What stood out wasn’t individual talks, but the space between them.

FOSDEM leaves room for conversations without a fixed outcome. Ideas can stay open, change direction, or stop without needing to be polished or defended.

That kind of interaction is hard to fit into tightly structured, sponsor-driven events, but it happens naturally here.

Overall, the format favors discussion and exchange over passive listening, which makes the experience noticeably different from more centralized conferences.