Hi, I'm DARIO

Designing and coding useful digital products with years of hands-on experience behind every project

15+ years experience 100+ projects, from small builds to giant platforms

Development & tools

Over 15 years of building for the web.

I've worked across most parts of the process — from database structure and backend logic to frontend interfaces, deployment and UX decisions.

My everyday work is mostly PHP, MySQL, JavaScript and CSS, but the technologies themselves are only part of the job. A lot of my work is about connecting systems, improving existing products, solving unusual requirements and keeping long-running projects maintainable.

Backend & applications

Building and maintaining custom web applications, ecommerce projects and integrations — often on systems that have been running and evolving for years.

Frontend & UX

Turning backend functionality into responsive interfaces, with attention to usability, accessibility and the details people actually interact with.

Workflow & delivery

The work doesn't end when the code is written. I care about how projects are versioned, tested, deployed and kept maintainable over time.

Design & product thinking

My background also includes visual design and UX, which helps me bridge the gap between technical implementation, interface decisions and the original product idea.

Selected work

Most of my professional work has been created as part of an agency team. Over the last 12 years, I've worked on websites, ecommerce projects, internal applications and digital services — sometimes as a developer, sometimes taking responsibility for the product as a whole.

The projects below aren't presented as things I created single-handedly. They're a selection of long-term work where my role ranged from PHP development and integrations to project ownership, UX and product decisions.

Featured / selected agency work

Email marketing platform

MAILservis

A project I've been continuously involved with for more than a decade. MAILservis is an application for creating, managing and sending email newsletters, and my role has gradually grown far beyond development itself.

Today I work on the product as a whole — from interface and workflow decisions to technical development, long-term architecture and keeping the platform aligned with changing requirements and legislation.

My role Product owner · Development · UX · Technical direction 10+ years of continuous development

Public website & digital services

National Museum

One of the projects that best reflects how my role has evolved over time. I originally joined the project as a PHP developer and gradually took responsibility for much more of its technical and product direction.

Today my work includes coordinating integrations with the museum's systems, solving requirements across different parts of the platform and contributing to UX and interface decisions.

My role Project owner · PHP development · Integrations · UX PHP developer → technical responsibility → project owner

Public websites, services and integrations

Museums & cultural institutions

Over the years I've worked on digital projects for several major Czech museums and cultural institutions. Although every project is different, they share many of the same challenges: large amounts of structured content, integrations with external systems, accessibility, long-term maintenance and interfaces used by a very broad audience.

This work ranges from public websites to visitor-facing services and custom integrations, usually developed as part of a wider agency team.

National Agricultural Museum
National Technical Museum
Jewish Museum in Prague

My role Development · Integrations · Frontend · UX

Internal platform · Details private

MAKRO / Můj obchod

Work on a large internal web platform within the MAKRO / Můj obchod environment.

The project is covered by NDA, so implementation details intentionally remain private. It nevertheless represents an important part of my experience with long-running, business-critical web applications and agency development.

My role Agency development · Long-running web application NDA

More agency work

And a lot more in between

Alongside these projects, I've worked on dozens of smaller websites, ecommerce projects, microsites, integrations and long-term maintenance tasks.

Most don't make sense as standalone portfolio case studies — sometimes my contribution was only one particular part of a much larger project. Together, however, they make up a large part of the practical experience behind how I approach web development today.

Websites · Ecommerce · Microsites · APIs · Integrations · PWA · Maintenance · Legacy systems · Analytics · Internal tools

Personal projects

Small projects are where I can build things simply because I find the problem interesting.

Smart home · Personal project

Project 615

My long-running personal smart home project — a place for experimenting with connected devices, automation, sensors, integrations and all the small problems that appear when different ecosystems are expected to work together.

Visit project615.cz ↗

E-ink · Public transport · Golemio API

PID departure boards

A small side project built around Prague public transport data: custom departure boards using e-ink displays, Golemio data and lightweight web applications.

Not a big product — just the kind of thing I enjoy building when software can make something physical a little more useful.

Personal me

A peek into my personal and travel diary.

I'm human as you (I hope), so this is just few moments from my travel, bikes, LEGO, and everything that catches my eye.

Have a project, idea, or technical challenge?

Get in touch and we can discuss what should be built, the right scope, and the fastest way to validate the direction.

hello@dariokolar.cz See how I work