Daniel Hoelzgen

Daniel Hoelzgen

@dhoelzgen.dev

#ElixirLang and #Ruby Lead Developer at 9elements, an agency for outstanding digital products. Focused on Artificial Intelligence, Logic, and Data Visualization.

999 followers647 following76 posts

Joint meetup with the Elixir Cologne group, Phoenix flavored talk about accessibility, and barbecue at the rooftop. Excited about a very special #elixir meetup!

Elixir Ruhr@elixir-ruhr.dev

Fourth Elixir Ruhr Meetup, and our first together with the Elixir Cologne Meetup. Barbecue on the @9elements.com rooftop terrace if the weather allows. Ariadne Engelbrecht is talking about accessibility as a real quality attribute, through a Phoenix/LiveView lens. www.meetup.com/elixir-ruhr-...

Thank you, this means a lot to us. Elixir has been steadily becoming a bigger part of what we do at 9elements, and that growth has been shaped by the openness and warmth of the BEAM community. We are glad we can support this awesome community by sponsoring Code BEAM Europe!

Code BEAM@codebeam.bsky.social

Please welcome 9elements to Code BEAM Europe 2026! We are so excited to have them on board as our official Lanyard Sponsor for Haarlem. Thank you to the entire 9elements team for championing the BEAM ecosystem and helping make this event possible. Check out them at: 9elements.com

I am proud that @9elements.com is sponsoring ElixirConf EU this year! For us, ElixirConf is one of the most important gatherings in the Elixir ecosystem. The talks are inspiring, and the community is genuinely one of the friendliest in tech. Can't wait to be part of it. #ElixirConf #ElixirLang

ElixirConf@elixirconf.bsky.social

Excited to announce @9elements.com as our Lanyard Sponsor for ElixirConf EU 2026! Thank you for supporting the community! www.elixirconf.eu#sponsors

Daniel Hoelzgen reposted

usage_rules now supports copying skills from your packages in addition constructing skills from the usage rules files 😎 Package authors can now provide entire skills for your project, and when you update your dep you can get the new version of the skill! #ElixirLang

Our team built the app backend for a major German sports club, and it was one of the most exciting projects to come out of @9elements.com. Can't wait to listen to @nickidee.bsky.social's talk to get some insight on how they handled scalability and performance.

Elixir Ruhr@elixir-ruhr.dev

Next meetup scheduled: On March 26, 6.30pm in Bochum, @nickidee.bsky.social from @9elements.com will talk about building sports app backends with #elixirlang - what it takes to handle hundreds of thousands of fans hitting the same app at kickoff. See you there! www.meetup.com/elixir-ruhr-...

Booked my ticket for Elixir Conf 2026 in Málaga, looking forward to a few great days with the community. Happy to have four coworkers joining me this year.

Quite impressed that we have 40 registered attendees, looking forward to the meetup tomorrow!

We just announced our next Elixir Ruhr meetup! Looking forward to Christoph's talk, and to plenty of great conversations with the local community

Elixir Ruhr@elixir-ruhr.dev

Save the date: Our second Elixir Ruhr meetup will take place on December 4th, 6.30pm in Bochum. Christoph Gnip, CIO of profection group, will talk about the Power of Process Orchestration. We would love to see you there: www.meetup.com/elixir-ruhr-...

I am pleased to share that @9elements.com is sponsoring @codebeam.bsky.social Europe 2025! As we continue strengthening our focus on Elixir, Phoenix, and Ash, it feels great to also deepen our role in this wonderful community. Looking forward to meeting many of you in Berlin!

Code BEAM@codebeam.bsky.social

🎉 Proud to announce 9 Elements as a lanyard sponsor for Code BEAM Europe 2025! They develop tailor-made software solutions combining craftsmanship with innovative design. Thanks for supporting the BEAM community! codebeameurope.com#sponsors

Daniel Hoelzgen reposted

Nearly thirty people joined our first meetup yesterday and we're so happy you came. Thank you for the great conversations and for helping us grow the local #elixirlang community!

Grateful that our first @elixir-ruhr.dev meetup brought together so many people - Our local community feels stronger than ever! Had a lot of fun talking about @ash-hq.org. A big thank you to @discord.com for saving the day when streaming didn’t go as planned. Join us here: discord.gg/TRqQcxRMjq

discord.ggJoin the Elixir Ruhr Discord Server!lixir Ruhr is a welcoming meetup for everyone excited about Elixir, Erlang, and the BEAM community. All experience levels are welcome! | 22 members

Really looking forward to our first Elixir Ruhr Meetup! I'll be giving an introduction to @ash-hq.org & Ash AI. Been having lots of fun with it lately and can't wait to share. Excited for good conversations and a great evening with the community. #elixirlang #myelixirstatus

Elixir Ruhr@elixir-ruhr.dev

Our first Elixir Ruhr Meetup takes place on Sept 25 at @9elements.com in Bochum. @dhoelzgen.dev will introduce @ash-hq.org & Ash AI, followed by networking, drinks and food. Proud to be part of the Global Elixir Meetups by @swmansion.com. #elixirlang #myelixirstatus

Really happy to finally move forward with rebuilding the local #elixirlang meetup in the Ruhr area. If you’d like to be part of it, join our Discord or just reach out to me here.

Elixir Ruhr@elixir-ruhr.dev

We are excited to share that the Elixir Ruhr Meetup now has a brand new CI and website. A big thank you to our incredibly talented designer, @ichimnetz.com! Go check it out and brew some magic: elixir-ruhr.dev #elixirlang #ruhrarea

We are looking for an #elixirlang / #rubylang lead developer in Bochum / the Ruhr area. If you love building great software instead of managing bullshit tickets, know how to work with clients and how to make sure your team grows, let's chat!

You will find a great team, short decision-making paths and modern tech & tools. We believe in work that fits into life, with fair working hours, an open culture and room for personal development. We genuinely enjoy what we do, and work together to keep it that way.

9elements.jobs.personio.deElixir / Ruby Lead Developer | Jobs at 9elements9elements is a home for coders and designers, a place for the makers and shakers, a playground for the crazy ones. It could be yours as well.

As AI redefines software development, this post by @ichimnetz.com stands out; tracing how automation shifts value from craft to concept, from 19th-century painting to today’s programming. Appreciate he draws thoughtful parallels without pretending to predict where it all leads.

Nils Binder@ichimnetz.com

There was a time when anyone could be an artist 👨‍🎨 — if they loved the work enough. Then came the professionals. Then came the camera. Today, it’s not paint that’s being replaced. It’s code. 9elements.com/blog/when-sk...

#ElixirConf 2025 was absolutely wonderful. First one since 2017, and the community is still just as great, lovely, and open. Tons of inspiring talks and conversations, can’t wait to try Ash AI! See you at the next one, hopefully not in another 7 years.

If you need your LLM to follow instructions better, try GPT-4.1. I’m building a chatbot with more complex behavior and struggled to get 4o to follow instructions properly. Switching to 4.1 fixed it, even without gimmicky styles to signal what's important.

This morning, I talked with my daughter about weekdays - specifically, what day it will be after a given number of days. I explained that adding multiples of seven doesn’t change the weekday, only the remainder matters. Not the easiest concept for a four-year-old.

Yesterday, I released a tiny MCP server that allows Cursor Editor to get up-to-date version information for external Hex dependencies. Someone suggested doing a version for #RubyOnRails, so I built a more generic version that supports Ruby Gems, Hex, PyPI, and NPM. dep-mcp.9elements.com

dep-mcp.9elements.comPackage Version MCP Server - For AI ToolsHelp AI tools like Cursor to automatically use the correct package versions when adding dependencies to your projects. Supports Hex, RubyGems, and NPM packages.

I am incredibly proud of the work of @molily.de and his team at @9elements.com, visualizing public health data on the WHO data hub. If you are into data visualization, this is certainly worth a look!

molily@molily.de

For the past three years, @9elements.com has worked collaboratively with UK agency Kore (www.kore.uk.com), helping the World Health Organization (WHO) to visualize global public health data on WHO’s data hub: data.who.int Read our blog post: 9elements.com/blog/visuali... #DataViz #PublicHealth

Daniel Hoelzgen reposted

I thought it might be fun (and possibly helpful to others) to create a thread to document the things that I learned or used for the first time while doing AoC with Elixir. #adventofcode #elixirlang #myelixirstatus

“You suddenly have superpowers. You almost don’t notice it. Being freed from all the mundane concerns of typical full-stack development lets you focus on just shipping features.” Love this part; absolutely on point. #ElixirLang #LiveView

Planning which #ElixirLang conferences to attend next year? @jola.dev got you covered with a nice overview page

johanna@jola.dev

I want to share something I built for the Elixir community: elixirevents.net ✨ I want to make it easier to find events like conferences and meetups, to help the community grow. Anyone can contribute, events are only visible with admin approval. For feature requests or feedback please let me know! 🙏

Seeing both the #Ruby and #ElixirLang starter packs grow makes me really happy. Thanks for keeping them up to date!

Josh from Honeybadger@joshuawood.honeybadger.io

I’ve added lots of new Ruby folks to my Ruby and Rails starter pack—one of the oldest and most used starter packs on Bluesky! Go check it out again and follow more Rubyists! go.bsky.app/HD2Ty2o #RubyConf #RubyConf2024 #Ruby

I am surprised at how bad ChatGPT is for Elixir, especially when comparing it to Ruby. Sure, I got some strange answers for Ruby, too, but for Elixir, both discussions with ChatGPT and CoPilot are so full of hallucinations that I currently just keep my hand off them completely.

Do you have recommendations for #Elixirlang books, courses, or posts that focus on functional programming patterns instead of the language / standard library itself?