We are Kolosek
An AI-native agency of senior engineers building intelligent software that transforms businesses.
Since 2011 we have partnered with more than 30 brands from America, Europe & Australia
Building software that
thinks for itself
We exist to help businesses harness the power of AI. Not as a buzzword, but as a core part of the products we build. Every line of code we write is designed to make your business smarter, faster, and more efficient.
15+
Years of experience
200+
Projects shipped
50+
AI projects delivered
30+
Team members
From consultancy
to AI-native agency
We started as a software consultancy, helping startups and enterprises build reliable, scalable products with Ruby on Rails and React. Over the years, we shipped hundreds of projects across industries, earning a reputation for quality and speed.
When the AI revolution arrived, we didn't just add it to our services list. We went all in. We rebuilt our workflows, retrained our team, and redesigned how we approach every project. Today, AI is embedded in everything we do, from how we write code to the products we deliver.
2011
Founded as a Rails consultancy in Novi Sad, Serbia
2018
Expanded to full-stack with React, Python, and cloud-native
2023
Pivoted to AI-native development with LLM integrations
Today
A full AI-native agency shipping intelligent products worldwide
Senior engineers who
live and breathe AI
No juniors, no outsourcing. Every person on your project is a seasoned engineer with hands-on AI experience. We're a tight-knit team that ships fast and takes ownership.
Deep AI Expertise
Our engineers work daily with LLMs, RAG systems, fine-tuning, and production ML pipelines. AI isn't a side skill, it's our core competency.
Full-Stack Builders
From database schema to UI polish, our engineers handle the entire stack. No handoffs, no gaps, no excuses.
Direct Communication
You talk directly to the engineers building your product. No project managers playing telephone, no unnecessary layers.
The tools behind
our AI products
We pick the right technology for each project, not the other way around
What drives
everything we do
Speed
We ship fast because our clients need results yesterday. AI-assisted workflows mean we deliver in weeks what others take months to build.
Quality
Speed without quality is waste. We write clean, tested, production-ready code that scales and is easy to maintain long after we're done.
Ownership
We treat your product as our own. No finger-pointing, no "that's not my job." Every engineer takes full responsibility for their work.
Transparency
No surprises, no hidden costs. You see every commit, join every standup, and know exactly where your project stands at all times.
Giving back to
the community
Kolosek is an open source software company. We develop and share openly, contribute to projects we use, and support local conferences, movements, students, and teaching facilities like Rails Girls.
