Welcome everyone!

I'm Daniela, a full time developer working on Bitcoin 🧑‍💻

This channel is where I'll share a mix of things I find intriguing - expect content on Bitcoin and computer science, and occasionally, other topics that catch my interest 🧬

Enjoy!

💧I recently switched to Hyprland, and so far, I've been loving it!

🖥 Hyprland is a window manager for Linux built on Wayland. It automatically arranges open windows in a grid so they never overlap; you can open and move windows around using keyboard shortcuts.

🧑‍💻 Hyprland is fast, lightweight, highly customizable, and looks great. I love it for coding because it allows me to split my screen into two halves: one for code and one for compilation output, documentation, or Google searches.

📕 The only downside I've found is the steep learning curve. Like other tiling window managers, you need to learn keyboard shortcuts and manually configure most utilities like the status bar, screenshot apps, and notifications.

🦥 Header image is from hyprland.org

I came across an article on how to give the right amount of context to people - which is challenging yet essential, especially in the workplace.

Here's my favorite tip - it's easy to implement, and quite effective :)

Remind them where you left off.

Task switching takes a tremendous amount of energy. Your manager is probably reading your note in between meetings (or during one!). Assume they’re reading with partial attention. Remind them where you left off so they can task switch faster.

🚫 “Here’s the updated link.”

✅ “Here’s the updated pitch for X customer. I incorporated your feedback and included a change summary below. Let me know if you have any questions. I’ll plan on shipping tomorrow morning.”

You can read the full piece here, I hope you find it useful 🧑‍💻

🤔 How do programming languages work?

🧑‍💻 At the simplest level, programming languages are just sets of rules that let us talk to computers. We write some code, follow the rules, and voilà—the computer does what we ask. Simple, right?

🧙‍♂️ But if you dig a little deeper… things get a bit more mysterious. Honestly, not many developers really know what’s happening behind the scenes. For many of us, the idea of creating a programming language sounds fun, but also kind of like wizardry—something only a few enlightened developers could pull off.

📚 I changed my mind when I started reading Crafting Interpreters - it's well written, engaging, and beautifully illustrated. It guides you through the process of writing an interpreter for a programming language called "Lox," making the whole experience accessible and hands-on. While the book primarily uses Java and C, the examples have been adapted into many other programming languages by contributors (yes, even Rust!)

🤑 And the best part? The HTML version of the book is free, so you can explore it at no cost, and if you love it, you can buy it to support the author :)

🦀 I had the pleasure of reviewing and writing the foreword for Braiins' latest book, Building Bitcoin in Rust!

🧑‍💻 This book is exactly what I needed when I started my journey into Bitcoin development - it's perfect for developers of any skill level who want to deepen their understanding of Bitcoin, Rust, or both.

⚙️ The approach is very practical: after a brief introduction to Rust and Bitcoin, it guides you through building your own simplified versions of a Bitcoin node, wallet, and CPU miner. You might think this is useless - who even uses CPU mining anymore?! - but to me, there's no better way to deeply internalize how something works than building it from scratch.

🥰 You can buy a paper copy or download the free ebook here. Enjoy!

🏗 Privacy is like... a Jenga tower?!

🥷 Many people think privacy is all or nothing, but that's a bit... simplistic. The Bitcoin Privacy Jenga Zine does a great job explaining how privacy (or the loss of it) really works and how our everyday choices stack up to impact it.

🎲 And if you're into board games, you can even play a Bitcoin-privacy-themed Jenga! Just head to bitcoinjenga.com – you'll find instructions to build the game yourself or a list of Bitcoin conferences that host it.

🌈 I love Bitcoin-themed games; they’re a great way to make important concepts accessible to everyone ✨

😴 Love going back to sleep right after turning off your alarm? Same here—it’s practically a skill at this point.

😈 Meet Chrono - an open source alarm clock app with a twist. To turn off the alarm, you need to complete minigames designed to wake you up. You can choose from typing out long sentences, testing your memory, or the ultimate nightmare... solving math problems!

🥱 I won’t lie—waking up to math isn't fun. But hey, it actually works for me, so I guess it’s worth it.

⚠️ Heads up: Chrono is still a work in progress, so you might run into a few bugs. Always keep a backup alarm through your system clock, just in case!

🎄 Christmas Favorites Edition 🎄
It’s Christmas time! Why not enjoy three (and a half) favorites instead of just one?

🎮 Saving Satoshi
An incredibly well-done Bitcoin adventure for developers. It’s a great way to start learning how Bitcoin works under the hood without it feeling overwhelming. The mix of technical text and code challenges is perfect for anyone with basic coding skills.
I love the cypherpunk style of the website, and the visuals are gorgeous - I especially loved the mining ones in chapters two and three!

🧑‍💻 Start your career in bitcoin OSS
If you’re feeling ready to dive deeper into Bitcoin development, check out the free BOSS program! It’s a great way to kickstart a career as a Bitcoin developer. I’ve joined a couple of Chaincode cohorts in the past, and they were amazing for building skills, meeting peers, and staying motivated to contribute to open-source projects. Honestly, it’s incredible that this level of education is available for free.

🧙 Magium - A DnD-Inspired Text RPG:
This text-based RPG has been my go-to while waiting in lines (way better than endlessly scrolling social media). You play as Barry, a regular guy who enters a deadly mage tournament, hoping to win and become a mage himself. Like Dungeons & Dragons, you make choices that shape the story and tweak your character’s stats.
Available on Android, iOS, and well, paper.
(If you’re into DnD, I’ve also been obsessed with Baldur’s Gate 3 lately, although you’ll need something a bit more powerful than a dumb phone to play it 🎮)

🎉 Happy January 3rd! 🎉

🧑‍💻 People say the first Bitcoin block contains a special sentence. Why trust them when you can verify it yourself? If you have a node, it’s easy to do!

🔍 Here’s how:

- Retrieve the first block using the commands bitcoin-cli getblockhash and bitcoin-cli getblock.
- Use jq to extract the coinbase field.
- Finally, convert the result from HEX to ASCII using xxd.

bitcoin-cli getblock $(bitcoin-cli getblockhash 0) 3 | jq -r .tx[0].vin[0].coinbase | xxd -p -r && echo ""

Cheers! 🥂

🎙 I was a guest on the Bitcoin Optech Podcast today, talking about my latest post on Delving Bitcoin. It covers a fingerprinting attack that can help identify Bitcoin nodes running on multiple networks.

🫣 If you didn’t understand anything about that first sentence - that’s totally okay! Bitcoin isn’t broken, and this “attack” isn’t anything to worry about :)

🧑‍💻 If, instead, you're deep into Bitcoin Core P2P, this one's for you. We gave a high-level overview of how nodes communicate and share network addresses, then looked into the attack itself and what could be done to fix it.

📝 You can listen to the podcast here, and you can read my Delving Bitcoin post here!

🧸 The teddy bear in the image is from my BTC Prague talk - I hope to write a blog post or at least share the slides soon! It’s also been a while since my last message, so thanks for still being here :)

🐳 “Bitcoin boils the oceans,” “Bitcoin wastes energy”…
We’ve all heard these kinds of claims from the mainstream media, but they never really made sense... Bitcoin uses energy to create fair money, what’s the problem with that?

🫧 Still, when you're debating with Bitcoin skeptics, it helps to have more in your arsenal than just “Boils the ocean? Cool, free saunas.”

🏰 That’s where bitcoinmythology.org, built by the Spiral team, comes in.

🧚‍♀️ The site is built like a series of short myths. Each one turns a common argument against Bitcoin into a funny creature, like a tree that complains too much, or a vampire that wants your electricity. Then it explains why the argument doesn’t hold up.

🌈 Here’s my favorite example, in response to “Bitcoin uses more energy than regular money”:

The truth about government-issued currencies is that they aren’t backed by much more than a promise. And when they are, the things that support them are militaries, police forces, arcane legal systems, unaccountable banks, and mints they can fire up at will.
All of these things consume vast amounts of energy—and it’s rarely green.

🤓 Happy fairy-tale studying! 🧑‍💻

🧁 I’ve started sharing my personal notes on Bitcoin Core on my github: https://github.com/danielabrozzoni/bitcoin-notes

🧑‍💻 Right now, it's mostly a mix of my thoughts on various P2P components and some C++ learning notes, but I plan to keep expanding these over time!

🤓 No matter where you are in your Bitcoin journey, I really recommend writing down what you're learning and putting it out there.
It might help someone else, but even if it doesn't, it keeps you motivated, and seeing your collection of notes grow over time is incredibly satisfying!

🥂 Happy learning!

Hey! Let's try a different format today: I will share something non-Bitcoin related I've been enjoying lately (a book, a videogame, etc), plus a hopefully-interesting, lesser known, technical Bitcoin explanation :)

🏰 1. Something I've been enjoying lately...

Kirby and The Forgotten Land for Nintendo Switch. I think it might be a kid's game... but honestly, that's part of the charm. It's bright, playful, incredibly funny. Perfect if you just want to pick up a controller and relax for a while!

🤓 2. Nerdy Bitcoin fact: The FEEFILTER message, and the weird setting 0.5% of the nodes have...

I was recently crawling the Bitcoin network to see what minimum feerate nodes are willing to accept. For a long time, the default minimum feerate was 1 sat/vbyte, but with Bitcoin Core v30 that default was lowered to 0.1 sat/vbyte. That made me curious: how many nodes accepted 0.1 sat/vbyte a few months ago, and how many do so now?

Answering this is actually quite straightforward. When Bitcoin nodes connect to each other, they exchange a message called FEEFILTER, which essentially says: “this is the minimum feerate I’ll accept in my mempool.” By connecting to nodes and recording their FEEFILTER values, you can get a pretty good picture of fee preferences across the network.

Most nodes behave as you’d expect. At the moment, about 27.7% of nodes accept 0.1 sat/vbyte as their minimum feerate. Back in September, that number was only around 2–4%.

But there’s a weird outlier...

Roughly 0.5% of nodes advertise an absurdly high minimum feerate, around 9000 sat/vbyte. That’s so high that no normal transaction would ever be accepted. Why would anyone do that?

It turns out these nodes are doing the first blockchain sync, and since they're spending their time downloading and verifying the whole blockchain, they don’t want to deal with mempool transactions at all. Instead of implementing some special logic, Bitcoin Core simply sets their minimum fee to something unrealistically high, effectively filtering everything out. Fair enough!

If you want to know more, check out my Delving Post or the Bitcoin Optech episode #373. Cheers 🍻