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      d$$$$"   / / / __ \/ _ \
    .$$$$$"   / / / / / /  __/
   z$$$$$"   /_/ / / /_/\___/  __    __        _
  z$$$$P        / /   (_)___ _/ /_  / /_____  (_)___  ____ _
 d$$$$$$$$$$"  / /   / / __ `/ __ \/ __/ __ \/ / __ \/ __ `/
*******$$$"   / /___/ / /_/ / / / / /_/ / / / / / / / /_/ /
     .$$$" __/_____/_/\__, /_/_/_/\__/_/ /_/_/_/ /_/\__, /
    4$P"  / ____/___  _/__/ / __/__  ________  ____  /__/____
   z$"   / /   / __ \/ __ \/ /_/ _ \/ ___/ _ \/ __ \/ ___/ _ \
  zP    / /___/ /_/ / / / / __/  __/ /  /  __/ / / / /__/  __/
 z"     \____/\____/_/ /_/_/  \___/_/   \___/_/ /_/\___/\___/

Talks were outstanding.
Awesome community centered about building stuff.
Spent only sats during three days.
Visited nice places and met original people.

I started writing this post in the Berlin Tegel airport. Totally exhausted but with a lot of thought in mind. The lightning conference was a success. It was the first Bitcoin only conference I attended and I feel like Alice waking up after her rabbit hole dream.

During three days, I was completely in a different world, more technical, more futuristic with really original, passionated and passionating people. I cannot go further into the details, but I wanted to give my overall experience.

The Lightning Network is a layer on top of Bitcoin enabling fast transaction with more privacy features. Powered by bidirectional payment channels and smart contracts, this is one of the most exciting solutions for Bitcoin scalability. One year after the first mainnet channels opened, more than three implementations of the BOLT specifications exist, a community of developers and hackers is forming and the size of the network is still growing. The Lightning Conference is the first international event focused on this technology, and I wanted to be here, to feel the vibe :)

Day 0 - The Meetup dev

Location: AHOY

My plane landed the morning, at 9:00, and I went directly to the meetup. The space was quite big but quickly crowded by nerds like me. Wearing Dark clothes for the most of them, a Club Mate in one hand, the other with a computer and asking the wifi code and a power plug.

As described in the invitation email, it was an open meetup without any prior agenda, focused on technical questions about the Lightning Network. We had tables to sit down and work on, as well as a small area for impromptu talks, announcements or demos. All of it was completely self-organised.

I attended the rust-lightning workshop organised by ariard. The exercise consisted of cloning a bootstrapping repository familiarizing with the library interfaces and writing a minimal implementation of a lightning client. The lack of space in the main room droved us to work in front of the bar. It was difficult to discuss in this area because of the noise, but it remained very instructive.

My check-in to the hotel was at 6:00pm. I left the space, took the subway and got out at the nearest station. I then could have taken the bus, but I wanted to explore Berlin’s streets. Walking along a wall, thinking of the Lightning, the exciting future to come, I noticed after several hundred meters how long this wall actually was and the size of its paintings.

On a little sign, near the ground, was written: Berliner Mauer.
One month before its 30th anniversary, this wall did not catch my eyes.
The contemporary concrete and its cold appearance felt actual.
A rigid line separating families and friends felt actual.

The rain did not spoil the after-party, which was organised in a nice pub Hirsch & Hase, near Voltastraße station. Free Beer and free food ! But after hanging out with the French people group, we decided to try the famous Room77 pub.

Room 77 and the 600,000th block

Location: Room77 - Graefestraße 77, Berlin

 ──▄▄█▀▀▀▀▀█▄▄─  Room77 is one of the first place in the world which
▄█▀──▄─▄────▀█▄  accepted cryptocurrency payments.
█────█▄▄▄▄▀───█  A big Bitcoin sign in neon welcomes you as you enter in
█────█────█───█  a warm room with a cypherpunk ambiance. Price is decent
▀█▄─▀▀█▀█▀──▄█▀  and service great.

We had a lot of fun in this pub, which is quite cosy and pleasant. It was certainly the first and the only time we enjoyed it not overcrowded by the thirsty lightning community. Paying with lightning was really easy, a small machine displaying the qr-code was passed around by the staff who seemed totally used to handle this kind of transaction.

Coincidence or not it was the same night that the peer-to-peer distributed timestamp server of the Bitcoin protocol would generate its 600 000th block, generating a computational proof of a chronological order of transaction for thousands of peers of its network and anchoring in time the issuance of 12.5 bitcoins inside the existing 18 millions. We waited for it, drinking beers and discussing about mostly informatics and community, refreshing some time a bright web page on our phone in the subdued light of the pub.

We spent all our time in the bar until the 600 000th block happened, local time was around 2am. We celebrated it with a round of applause and a last drink, but tired by this long day I was happy to go to bed.

Day 1 –

Location: KÖPENICKER STR. 16 - 17 10997 Berlin

    ##     Cafe was served in front of the conference building
   ####    by the people of the Paralelni Polis truck and sponsored
  ##  ##   by Bitmex.
 ##    ##  Inside the truck, was a art gallery about the concept of
##  ###### Cryptoanarchy and the unregulated internet.

Talks, I attended:

  • 10:10 Enterprise Lightning FTW - Jameson Lopp
  • 10:30 Make me an offer: Next Level Invoicing - Rusty Russell
  • 11:00 How much Better Could Lightning Be? - Fabrice Drouin
  • 11:20 pAMP it - Conner Fromknecht
  • 11:40 Of Channels, Flows and Icebergs - Christian Decker
  • 12:00 LSAT: Your Ticket Aboard the Internet’s Money Rails - Olaoluwa Osuntokun
  • 13:30 Building a More Friendly Lightning User Experience - Will O’Beirne
  • 13:50 Hedging the Chain - Jack Mallers
  • 16:00 Lightning x Liquidity, Or A Financier’s Guide to Staking Bitcoin - Lisa Neigut
  • 17:00 Lightning integration in Electrum - Thomas Voegtlin

Jack Mallers was really impressive, the talk was not really technical but it remained a great explanation about financial tools.

Olaoluwa Osuntokun talks fast, this fact is a meme in the community, but believe me or not even for a non-English speaker like me all is intelligible , and the quantity of relevant information, or deep in detail explanation of technical solution of complex problem is outstanding.

This first day, the main stage was very focused on technical part. It was really refreshing to listen to passionate people with a clear vision and even if all the audience and speakers have certainly a big bias when it is about the Lightning Network, the general spirit was: Congrats, the thing works, now we still have a lot improvement to do.

Sadly, I could not enter in the sponsored party, not enough place was reserved for the conference attended. The French group and I ended again in Room77.

Day 2 –

I spent more time on the second floor, playing with the hardware that people brought to the conference. There were a lot of funny machines, like a cocktail dispenser, beer taps, a polaroid camera, a blowing bubble robot, all connected to the Lightning Network, accepting sats as a price for the entertainment. Several companies exposed their products like home hosting Bitcoin node hardware or cold storage solutions. Around a big table with a screen at the end it, people were organizing workshops about open source software.

In a medium sized space, the second stage was taking place without a big scene only a projector and a microphone like a standard tech meetup. The talks were great, it was really pleasant to have this dimension of presentation. My favorite talk so far, was from Jonas Nick, cryptographer at Blockstream, who explained in a very clear way Schnorr signature properties.

I attended (but forgot the schedule):

  • Lightning Network in Paralelna Polis - Martin Habovstiak
  • Lightning and Journalism - Janine Romer
  • Trampoline Routing - Bastien Teinturier
  • Deploying Rust-Lightning in the Wild - Antoine Riard
  • Payment Pathfinding for Reliability - Joost Jager
  • Hight Throughput Cryptocurrency Routing in Payment Channel Networks - Vibhaalakshmi Sivaraman
  • 10 Things You Probably Didn‘t Know About Lightning Channels - Oliver Gugger
  • Current Approaches for Pathfinding of Payments on the Lightning Network - Rene Pickhardt
  • The Impact of Schnorr, Taproot, and Tapscipt on Lightning - Michael Folkson
  • Shrunken Schnorr Shortcuts - Jonas Nick

ZmnSCPxj made a talk presenting a huge amount of routing ideas for the Lightning Network, I forgot the title of the talk but it was hilarious to see her/him struggle to reach the end of her/him slides. This individual, who is maybe the most active and prolific writer of the lightning-dev mailing list care about privacy. I am happy that Square Crypto gifted ZmnSCPxj a grant.

I managed to take a picture with Olaoluwa Osuntokun who was patient enough to accept it even if he did not know me. The fan boy in me was ecstatic.

Someone in the French group had a contact with a member of the c-base hackerspace and we were invited to visit it.

c-base, a Raumstation unter Berlin


c-base is the oldest crashed space station on earth.

After entering through a corridor worthy of being the decors of a remake of 2001: a Space Odyssey, we were welcomed inside a big space with walls coated with electronic cards, colored neons and LED panels. We drank a beer near a pub counter with a futuristic vibe.

Our host guided us in the downstairs floor, following the story telling of the space he signalled our intrusion to the other spaceship’s members working inside by pressing a weird button. An Alarm rang and panels with Space Aliens form drawn on it switch on. The first floor seemed already impressive, but this ground was at another level. Even the ceiling was covered with wired, dells and buttons. We visited a Library, a room with a big mess of tools, soldering irons, space with computer screens and lava lamps.

I gifted my best Bitcoin sticker to our guide who in return gave us stickers with the Raumstation logo.

Unstack sats

I have unstacked a lot of sats playing with the funny hardware of the second floor, buying stickers, hot chocolate, coffee and beer. The speed of transaction was swift and fees were cheap, Although my Eclair Wallet had only two channels.

Spending everyday with my wallet contributed to the overall futuristic atmosphere and it was a great reminder every day that the technology , people were actually talking is real, it exists and it grows.

⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⢸⡿⠈⠂⠉⠄⠄⠄⠄⠈⠄⠉⠄⠄⠄⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| amount        | fee |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⢸⡇⠄⠄⠄⠄⠶⠶⠄⠄⠄⠄⠂⠶⠶⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 38 394,47     | 61  |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⢸⡇⠄⠄⠄⠄⠶⠶⠄⠄⠂⠄⠂⠶⠶⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 30 8469       | 0   |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⢸⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 101           | 1   |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⢸⡇⠄⠄⠄⠄⠶⠄⠶⠄⠄⠄⠂⠉⠄⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 226001        | 0   |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠈⡇⠄⠄⠄⠄⠶⠄⠶⠄⠄⠂⠂⠄⠂⠄⠄⠄⠄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 139 580,972   | 222 |
⠄⠄⠄⠄⠄⠄⠄⠄⠄⢀⠑⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⣿⠄⠄⠄⠄⠄⠄⠄⠄⠄| 402,643       | 0   |
⠄⠄⠄⠄⠄⠄⠄⢀⣔⣥⣄⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⣷⣦⣤⣐⡀⠄⠄⠄⠄⠄| 34 891,799    | 175 |
⠄⠄⠄⠄⠄⠄⣤⣴⣿⣿⡿⣇⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⣿⣿⡿⠟⠄⠄⠄⠄⠄⠄| 87 359,735    | 9   |
⠄⠄⠄⠄⠄⣰⣿⣿⣿⡟⠁⣿⠄⠄⠄⠄⠄⠄⠄⠠⡶⠄⠄⠄⠄⢀⢀⢄⣤⡟⠉⠄⠄⠄⠄⠄⠄⠄⠄| 80 374,362    | 402 |
⠄⠄⠄⠄⣼⣿⣿⣿⣿⠇⠄⣿⠄⠄⠄⠄⢀⣴⣮⣧⣡⣶⣾⢻⣼⣫⢮⣿⣿⡇⠄⠄⠄⠄⠄⠄⠄⠄⠄| 56 574        | 0   |
⠄⠄⠄⢰⣿⡿⢻⢽⣿⠄⣀⣿⠄⠄⠄⠄⢸⣿⣛⣿⣼⣻⡾⣿⢿⡻⣿⡟⣯⣿⣦⣤⡆⠄⠄⠄⠄⠄⠄| 45 258        | 0   |
⠄⠄⠄⣾⣿⡇⠄⠄⠘⣿⣿⣿⠄⠄⠄⢴⣿⠿⣿⡿⠿⣷⣻⣿⠵⣿⠻⢽⢷⣿⡿⠟⠄⠄⠄⠄⠄⠄⠄| 113 145       | 0   |
⠄⠄⠄⣿⣿⡇⠄⠄⠄⠄⠸⣿⣿⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⠄⣿⣴⠄⠄⠄⠄⠄⠄⠄⠄⠄| 1 130 551,981 | 870 |

At the current price: 83,37 euros


After this conference, I had some weird feelings like a post conference blues, which I would describe as watching a Train passing in front of me or a ship leaving me alone on the quay. Full of smart and funny people, the vehicle was heading to great adventures and discoveries. Fortunately there are plenty ways to contribute to the Lightning Development without working on Bitcoin for a living.

Rusty Russell said “This event reminds me of the early Linux days.” It definitely makes me realize of my privilege to attend the conference.

I am grateful for meeting this joyful and building community, witnessing its growth and inventiveness. I am amazed by the elegant solutions the developers comes up with to complex problems. I am overwhelmed by their new ideas and engineering concepts I would never be able to imagine.

Thank you to the organizers, it was awesome.