FrontKon#25 in Brno

The fourth edition of FrontKon — the biggest gathering of the Czech and Slovak frontend community — took place on October 1, 2025, at the Passage Hotel in Brno. More than 600 developers came to get inspired, learn, and share their experience at this full-day event organized by the Frontendisti.cz community. Superkoders was the afterparty partner, and we've put together a roundup of the most interesting moments from this year's edition.

This year's roundup was put together by Michal Kurečka, Petr Goca, Eliška Plitzová, and Jozef Rosenberger, with footnote insights added by Luděk Hradil.

CrUX: Data That Will Speed Up Your Websites

Michal Matuška

Michal presented a look at publicly available data from Google (CrUX) that can help developers optimize speed. The talk contained plenty of new information on how to read this data and what to focus on during development for better performance — and, most importantly, why it's essential to prioritize changes correctly.

Progressively enhanced
apps with Svelte

Paolo Ricciuti

Paolo Ricciuti focused on the concept of progressively enhanced applications in the Svelte framework. His key message was that modern apps don't always need to rely on JavaScript. He showed practical examples of forms that work even without JS — for instance, login forms with a fallback to the /login endpoint. One interesting point was handling autocomplete functionality, which can cause issues with auto-submit when JavaScript elements or routes aren't defined correctly. Accessibility was a central theme throughout the talk.

JavaScript is dead: 7 examples
where modern CSS alone is enough

Jan Svěrák

The talk focused on modern CSS features that already work reliably in production today and can replace what used to be common JavaScript hacks.
Using concrete examples, he covered techniques such as scroll-snapping, the :has selector, text-wrap, and the color-mix() function, which open up new possibilities for cleaner and more efficient code.

There were also practical tips, such as using scrollbar-gutter: stable to prevent CLS or aligning block-level elements with align-content: center. The talk showed that modern CSS lets us solve problems that used to be complex in a much more elegant way, without unnecessary dependencies on JavaScript.

If you follow our frontend news, none of the "hottest" CSS tricks probably came as a surprise anymore — after all, we wrote about the one that was supposed to blow everyone away almost a year and a half ago 😎.
All the examples from his presentation are available here.

From the Past to the Vision:
The Evolution of Livesport's Stack

Tomáš Hrstka

Tomáš Hrstka from Livesport took the audience on a fascinating journey through the technological evolution of their stack — from monolithic files (CoreJS, PHP) to modern, modular components and frameworks. He described the process of rewriting projects and the emergence of new ones, such as the Tribal Football project.
The talk showed how a large company handles technical debt and migrates to modern technologies.

When Great Code Isn't Enough

Pavel Lorenz and Filip Macek (Heureka Group)

The speakers from Heureka Group focused on the often-overlooked area of soft skills in technical teams. They emphasized that great code alone isn't enough — communication, knowledge sharing, and teamwork are key.
They warned against a "one-man show" approach and recommended effective task delegation.

"The key is communication."

Vibe Coding: How to Build Products
When You Don't Know What You're Doing (and It Works Anyway)

Martin Staněk

Martin Staněk offered a refreshing take on so-called vibe coding. He covered the entire process — from prototyping through prompting AI to actual application development. He mentioned practical insights like rate limiting for LLMs and shared experiences developers often run into outside the local environment. The talk was full of recommendations for anyone wanting to experiment with AI in prototyping.

"I liked the analogy where he compared the fears around vibe coding (security, efficiency, etc.) to the shift from assembly to higher-level languages like C — the fears back then were exactly the same."

From Routine to Efficiency:
How AI Saves Us Time in Development

Petr Malík

Petr Malík presented a pragmatic approach to using AI in development.
His main idea was clear — automate the 20% of tasks we do most often.
He recommended proceeding in small steps and applying an iterative approach.
He showed examples of automating and tagging work in time-tracking applications.

AI editors – how they work,
and how to master them

Matúš Congrády

Matúš Congrády dove into how AI editors work and explained their underlying principles.
The structure of the talk resembled Martin Staněk's presentation but went into more technical detail.
He mentioned things like working with context, MCPs, rules, and other aspects of the IDE environment.

Helping Password Managers
Help People

Michal Špaček

Michal Špaček showed how to make life easier for users in just a few minutes by setting up forms correctly.
He explained how password managers recognize when to offer to generate a password, and which input attributes they need for that.
He also presented well-known rules and a practical example of a password change flow.
The talk was packed with tips you could apply right away.

React Hook Form & Zod – a Duo That Helps You Build Forms Efficiently

Michaela Trčková

In her talk, Michaela practically demonstrated how to improve a simple form in four steps.
She first used React Hook Form to manage state and validate inputs, then added Zod for more robust typing and data validation.

She highlighted the main advantages of both libraries — React Hook Form reduces the amount of boilerplate code (e.g., via FormProvider), while Zod is a TypeScript-first, schema-based validation library with no dependencies. She also showed that the two libraries work great together and improve the developer experience when working with forms.
The full demo is available on her GitHub

AI Battle

A dynamic format where five projects had to be built in 15 minutes — two teams of two competed for the result.
Key takeaway: if you're trying out a new AI tool, test it first. If you know Claude Code is reliable, stick with it. If you bet on an unfamiliar tool, you can easily fail.

Vibe Projects:

• A 3D simulation of the Brno astronomical clock with hints on how to read the time
• A 3D simulation of the solar system
• Flappy Birds
• Maze Runner
• WebOS

Feedback Doesn't Have to Be a Fuckup

Irena Zatloukalová

TL;DR: Be tough on the problem, gentle on the people.
Irena showed just how challenging it is to give quality feedback. An evaluation alone isn't enough — what matters is how we communicate it so it actually has an effect.

Basic rules:

• They need to hear you – deliver it in a way that's appealing to the recipient, not to yourself.
• Giving instructions? Don't confuse them with your body language.
• Get clear on your intent – are you there to give, or to take?
• Ask more, talk less.
• Prepare.

Tailwind 4 vs CSS 6

Lukáš Trumm

Lukáš Trumm presented modern approaches in both CSS 6 and Tailwind 4. He highlighted, for example, @scope in CSS 6 and showed changes in how classes are defined in Tailwind (e.g., .mx-5). He emphasized that Tailwind isn't a replacement for CSS but rather an alternative to custom frameworks.

For larger projects, it can be worthwhile to combine Tailwind with CSS 6 – Tailwind is great for quick results, while a custom framework is better suited to specific solutions.

A Developer's Guide to Testing
Technical SEO

Pavel Ungr

Pavel Ungr focused on technical SEO and presented concrete tips for auditing websites.
He mentioned the importance of correctly using noindex tags, redirects, and testing functionality without JavaScript (e.g., pelikan.cz). He showed five useful browser tools and the use of Google Sheets for reporting: SEO checklist

"Great plugins for developers (e.g., SEO Toggle, Detailed, and others) plus a fantastic checklist for automating SEO checks."

CSS State of the Union Discussion

The discussion focused on the current state and future of CSS – the biggest trends, the role of JavaScript, and the move toward better-structured styles.
Moderator Tomáš Hejč (CEO of Superkoders) led the debate with Lukáš Trumm, Jan Svěrák, and Lukáš Chylík.
Topics included code organization (ITCSS, Tailwind), syntax clarity, and new features that would make developers' work easier – such as loops similar to those in SASS.

All's Well
That Ends Well

A day full of talks on AI, JavaScript, and soft skills wrapped up with a great stand-up set from Tigran. It was followed by an afterparty hosted by Superkoders, right at the Passage Hotel — the perfect place to keep networking in a relaxed atmosphere. It was great to see the community sharing experiences not just during the talks, but at the bar too.

"The one thing I'm taking away from Tigran is that gloriously Czech sentence: 'chodívám běhat' [I tend to go running] – something completely incomprehensible to foreigners."

FrontKon 2025 confirmed its position as the most important gathering of the Czech and Slovak frontend community. This year's edition was marked by strong interest in AI topics – from the practical use of AI editors to automation and AI's impact on the future of the profession. At the same time, it didn't forget classic topics like frameworks, performance, SEO, and soft skills.

Thank you for letting us be part of such a great event, and we're looking forward to the next one!