Szymon Fiedler
@szymonfiedler.bsky.social
I build software I’m willing to maintain for years. Payments, insurance, DDD. RailsEventStore maintainer. Arkency. wroclove.rb co-organizer.
I strongly agree with Weaver's "Callbacks Are Not Invariants": callbacks can't keep their promise, writes go through one door. The ingress doesn't own the invariant. The aggregate does. And the persisted fact, not the outbox, makes effects recoverable. blog.arkency.com/ingress-is-n...
Ingress is not the owner of the invariant
blog.arkency.com
As a Polish person I endorse this comparison to our national sport 🍄🟫🍄🟫🍄🟫 „I tend to treat performance gains like mushroom hunting. When you find a mushroom, it usually means that it’s an area where they grow well, and that no other mushroom hunter has passed by recently.”
With the new job, I didn't get much time or energy to blog lately, but I figured I'd use the various downtime while traveling to Ruby Kaigi to write about some of the things I worked on recently: byroot.github.io/ruby/perform...
That’s a wrap on wroclove.rb 2026! What we’ll remember most are the smiles, great discussions, and afterparty vibes. That energy keeps us going – sending a heartfelt thank you to everyone who joined us 🫶 May this postcard bring you all warm memories of wroclove.rb 2026!
This is Wrocław in 1825. Curious how it looks today and how it changed along the way? Join our free guided walking tour on Sunday at 15:00, right after the conference and enjoy Wrocław's charm! Sign up for the tour here ➡️ buytickets.at/wrocloverb/1... Source: fotopolska.eu
So happy to be speaking along with @cplanas.bsky.social, @yatishmehta.com and other Ruby folks!
This week’s RBQ Conf speaker highlights: - Cristian Planas - Yatish Mehta - Szymon Fiedler Community Pricing remains available for teams, students, and folks who are Open to Work. rbqconf.com
New post: A timezone bug that hid for months — using Time.now to get DST offset for historical dates. Simple fix, but a good reminder to test with explicit timezone manipulation. blog.arkency.com/the-timezone...
Tickets are now on sale! 🎟️ Amazing speakers, hands-on workshops, and great vibes ahead. Grab your ticket now! wrocloverb2026.konfeo.com/en/groups P.S. We’ve wrapped up CFP reviews and will announce the full agenda soon - stay tuned 🔥
Speaking at @rbqconf.bsky.social in Austin (March 26-27) about mutation testing for validating AI-generated tests. Topic emerged after months of experimenting with AI in legacy code at Arkency. Let's see if Mutant can catch bugs in LLM-written tests 😎 rbqconf.com#:~:text=Szym...
RBQ Conf
RBQ Conf is a regional Ruby gathering where code meets community, with meaty talks, saucy insights, and plenty of time to connect. Coming to Austin, TX on March 26 & 27, 2026.
rbqconf.com
CFP closes in 30 days! ⏳ If you’ve been thinking about submitting a talk, now’s the perfect time. We’d love to hear your ideas! And if there’s someone you’d love to see on the #wrocloverb stage - share this with them and give them a nudge 👀
The second batch of tickets is almost gone - we can't wait to see you all at #wrocloverb! 🤩 If you'd like to join us as a speaker, our CFP is still open and we're waiting to hear your ideas! Inspire your fellow developers, submit your talk here ➡️
PaperCall.io - wroclove.rb 2026
papercall.io
Santa is very generous to us today - he’s bringing two great announcements: 📣 Let’s welcome our first speaker - @ismaelcelis.com will join us to explore Event Sourcing and the Actor model in Ruby! 🎟️ The second batch of tickets goes on sale on Monday, Dec 8 at 10:00 CET - don't miss it!
That feeling when a single-purpose class eliminates 100+ instances of `message << " | "`. Ruby 3.4 forced my hand, but I'm not complaining. blog.arkency.com/the-joy-of-a...
The Joy of a Single-Purpose Class: From String Mutation to Message Composition
blog.arkency.com
I was recently reminded that not everyone fully understand what the frozen string literal magic comment is about. So I figured it was the occasion for another deep dive. byroot.github.io/ruby/perform...
Frozen String Literals: Past, Present, Future?
If you are a Rubyist, you’ve likely been writing # frozen_string_literal: true at the top of most of your Ruby source code files, or at the very least, that you’ve seen it in some other projects.
byroot.github.io
Serious question: What were the drivers behind enforcing Rubocop’s Style/CaseEquality rule (prohibiting ===) in your codebase? „rubystyle.guide said so” is not the answer that makes me satisfied.
I wrote about the designing the perfect type signature syntax in Ruby.
The journey to the perfect type signature in Ruby
joel.drapper.me
Why do we do this ourselves? We are feeding the rich with our knowledge without any benefits in return. Instead, they make content hard to read, hard to search, hard to edit, and hard to follow. And hire algorithms to throw trash into our feeds. More: dudulski.pl/2025/10/15/f...
~/We broke the internet. We can still fix it
Jan Dudulski personal site
dudulski.pl
Absolutely love it! I use @neovim.io, btw. 🤣
In the upcoming Herb v0.8.0 release, the Herb Language Server will support `Fix-on-Save`, `Format-on-Save`, or both! 🌿 This builds on the new `--fix` option in the Herb Linter, which can automatically correct offenses without formatting the rest of the document.
CFP for #wrocloverb 2026 is already open! ⏲️ We aim for ~30 min talk 🗣️ First-time speakers are more than welcome! 🗓️ We are waiting for your submissions until January 13th
PaperCall.io - wroclove.rb 2026
papercall.io
Save the date! @wrocloverb.com is back on April 17–19, 2026 💎 We’ve got big plans to make this edition unforgettable. Stay tuned for updates - and see you in Wrocław!
Periodic reminder: before you start organizing stuff, throw away anything unused first. Works for code, clothes, tools, art supplies.
- Turbo Drive - Turbo Frames - Turbo Streams (including broadcasting) - aaaand Stimulus Doesn't ring a bell? Don't worry. You can still come. We'll serve it on plate. The price? You just need conference ticket. That's all. So, see you there?
You can still join the From Static to Reactive: Hotwire Basics for Rails Devs workshop that @maciejkorsan.bsky.social and I will be hosting at @wrocloverb.com If you trust us with 180 minutes of your time you'll discover flavours of Hotwire such as: 1/2
Come, join our free webinar👇🏻
Is your #Ruby on #Rails app in jeopardy? I've been consulting for organisations that blame Ruby and Rails for being unable to develop the business further. The option they see is.. rewriting app to other technology Let's discuss rewrite vs modernization arkency.com/webinars/res... #RubyOnRails
Tired of slow ERB templates and messy view logic? Let's discover with @Seth Horsley how Phlex and RubyUI bring blazing-fast (12x!) and beautiful components to Rails while maintaining the Ruby way we all love. Join us to learn how to build modern UIs within the Rails ecosystem 🚀
Arkency homepage got a new nice UI. Along with the refresh we slowly start building the case studies section. Have you seen the latest one? arkency.com/case-study/t...
Arkency
The premier Ruby on Rails development agency est. 2006.
arkency.com
Workshops alert! @lukaszreszke.bsky.social and @maciejkorsan.bsky.social will run Hotwire workshops where you'll learn the best practices of this framework and get some hands-on experience 💻 Let them know what you'd like to practice there Registration opens soon, stay tuned 👀
What would you like to learn at Hotwire workshop?
Maciek and Łukasz are developing the shape of the Hotwire workshop. Help them prepare the scope of the workshop by answering these short questions
forms.gle