The 39th Chaos Communication Congress convened again at the Hamburg Congress Center from 27 to 30 December 2025. Roughly 15 000 visitors and participants attended a dense programme of talks, workshops and hands-on sessions. The event offered a familiar mix of technical depth, practical making and engaged community discussion that the CCC has become known for.
Volunteering as an “Angel” — roles and constraints
I have volunteered at previous Chaos events and returned this year as an Angel. The volunteer system is structured and inclusive: anyone with time and willingness can sign up, but many roles require briefings or prior experience. I arrived in Hamburg on 26 December to complete onboarding.
I was briefed as a Press-Angel Trainee (trainees shadow and learn from experienced press angels), but due to the high demand for that role I did not take a shift there. Instead I worked three different roles that illustrate the variety and operational needs of the congress:
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Camera Angel — operating fixed cameras in lecture halls. Each main stage typically has two cameras: Camera 1 for close ups, Camera 2 for wider shots. Communication with the video-mixer via intercom is continuous while on shift. The role requires attentiveness to framing and speaker behaviour, and avoids back-to-back shifts unless the talks are short. The guideline to limit camera shifts per person (2–3/day) is pragmatic: camera operation is cognitively and physically demanding, and giving more people a few shifts increases resilience and training throughput. Working as a camera angel was one of the most satisfying tasks for me; coordinating live cuts with the mixer and adapting framing to very different presentation styles improves both technical skill and judgement. Many recordings from the event are now available on media.ccc.de 🔗.
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Merch (FOC) Angel — handling merchandise logistics at the front of house and in storage. Tasks include unpacking boxes, replenishing sales tables, and delivering preordered items. The workflow requires inventory discipline and quick, accurate customer interactions. After a short time I was flagged as an “experienced” merch angel; prior practice at the Gulaschprogrammiernacht helped here. Good stock management noticeably reduces friction at peak times and frees up colleagues for other duties.
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Main-Bar Angel — working the central bars (e.g. Rubik’s Bar) where cocktails and simple drinks are sold. Shifts are longer and require stamina and reliable handling of transactions and crowd/liquid flow. I worked one evening with a colleague, assisting with order prep and service.
Across these shifts I logged roughly 24 hours of service over the four days. The scheduling and role-rotation are designed to spread expertise and to avoid single-point failures — a small but effective operational principle that keeps the event running smoothly.
Making and soldering — beginner to intermediate workshops
The hardware and maker area included many approachable projects for beginners and more advanced boards for experienced hackers:
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Blinken Lights provided a selection of PCBs for participants to solder themselves. These benches are useful entry points: they combine low barrier to entry with immediate tangible results. My partner will start on a simpler kit (an Axolotl with RGB eyes) while I picked up a Hakkaa board (https://github.com/hakkaatachi 🔗). Hakkaa is intended as both a soldering exercise and a platform for an ESP32 workshop with Rust — an example of how teaching and tooling can be bundled.
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CDC Badge (decentral.community) — the CDC badge uses an ESP32-S3 and a TROPIC01 secure element (https://github.com/riatlabs/cdc-badge 🔗). It features an e-ink display with frontlight, a keypad and LiPo connector. The project is early stage but already supports using the e-ink as a nametag. I’m particularly interested in evolving the firmware beyond C to include Rust support; possible downstream applications I’m considering are a decentralized mesh pager, an interactive nametag and a FIDO2 keystore. The badge is a concrete expression of the event’s emphasis on open hardware for workshops and prototyping.
Other appealing projects included an RGB light-stick (Luminous Rhythm Emitter 🔗), alternative language models and playful utilities like a Cloudflare error-page generator 🔗. There was a lot to catalogue; I plan to follow up blog posts on some of these projects after experimentation.
Talks — scale, themes and structure
Across four main stages there were approximately 140 recorded talks covering a wide spectrum:
- Security & Hacking and Hardware & Making retained strong presence, as expected.
- Science, Ethics, Society & Politics, and Art & Beauty programmes broadened the scope and provided space for interdisciplinary perspectives.
- The Community Track, introduced this year with its own stage, amplified local hackerspace and habitat work. These community talks often surface practical projects, replicable tools, and grassroots organisation patterns that don’t always appear on larger stages.
In addition to the main stages, many self-organised sessions took place. These sessions are deliberately small and interactive, and they are not recorded for media.ccc.de — the trade-off being privacy and unfiltered discussion versus broader dissemination. That trade-off is intentional: some conversations require a space where participants can experiment without the pressure of public recording.
Given the volume of content it’s impossible to attend everything. I plan to publish focused reviews and summaries of selected talks — technical write-ups that extract the methods, assumptions and practical takeaways for peers. If you can’t wait, the recorded talks are already online.
Practical impressions and operational takeaways
A few practical observations from the event:
- Shifts and training scale operational reliability. The Angel system turns volunteer throughput into organisational capacity. Short briefings and clear role descriptions lower barriers and build redundancy.
- Give people a few controlled, repeatable tasks first. The policy of limiting camera shifts per person is useful: it distributes experience and avoids fatigue-related mistakes.
- Workshops that bundle learn-by-doing and tooling (hardware + language + workshop) are very effective. Hakkaa and the CDC badge illustrate how a small leaning curve plus practical output increases follow-on engagement.
- Diversity of content matters. Having ethics and arts alongside security and hardware enables cross-pollination; the best ideas often appear where disciplines overlap.
Closing notes
39C3 remained a dense, productive event: a mix of technical depth, hands-on making and community exchange. I enjoyed reconnecting with colleagues, learning from new projects and returning with concrete items to explore further — particularly the badge and board projects I mentioned. Operationally, the Angel system continues to scale well by design: clear roles, short trainings and sensible limits on shift load keep the event resilient.
I’ll follow up with write-ups on selected talks and experiments. For peers who attended, I’m interested in comparing badge firmware approaches (Rust vs C). For those who could not attend, the recorded talks on media.ccc.de are a good starting point. I look forward to the next Chaos event in April and to continuing this line of practical exploration.