We design, build& ship AI-nativeproducts.
An AI-native product studio. We put AI to work across design, engineering and testing — shipping websites, APIs and AI features faster, without trading away quality.
What we do
The judgment of a senior team, at the speed of AI.
systems · prototypes · UI
Design
Interfaces with a point of view — explored and refined with AI so we cover more ground in less time.
react · next.js · typescript
Engineering
Production-grade React, Next.js and TypeScript — AI-assisted, human-reviewed, built to ship and scale.
llms · rag · agents
AI
LLM features, RAG and agents designed into the product from day one — with evals and guardrails, not guesswork.
Services
What we take on
Design, engineering and AI — from product interfaces to rapid full-stack proofs of concept.
AI integration
aiLLM features, RAG and agents wired into real products — shipped with evals and guardrails.
Full-stack POC
pocIdea to a working full-stack prototype in weeks — proof before you commit.
UI/UX design
designFlows, wireframes and polished interfaces — designed in the browser, against real content.
Website development
webMarketing sites and web apps in Next.js — fast, accessible and easy to maintain.
API development
backendTyped REST and GraphQL backends that frontends love to consume.
Mobile development
mobileReact Native apps that share code and ship to both stores.
End-to-end testing
qualityPlaywright suites that catch regressions before your users do.
Clients
In good company.
From venture-backed startups to public institutions across 3 continents — teams that want to move fast without shipping AI slop.
Become oneTestimonials
Words from people we’ve built with
Every quote is from a real client — unedited and unfiltered.
Karolis is the consummate professional. Highly personable, excellent communication skills, dedicated and technically astute. Along with all that he is a nice guy.
Cathal McAliskey
Lead IT Consultant · GemPool
Karolis is one of those rare developers who has an exceptional eye for detail, everything that he works on has a certain visual aesthetic to it. I was directly managing Karolis on a number of different projects at UserCentric for high profile enterprise clients of ours and all of the front-end work that Karolis did on those projects just looked great. He also has a strong self driven motivation to continue to learn and to stay up to date with whatever is topical in the dev community, and contributed a lot to our Engineering culture at UserCentric by always sharing with us what was the latest and greatest in the scene.
Kristian Tasevski
Head of Mobile · Bound
I have had the pleasure of working with Karolis across a few projects. Karolis has a very keen eye for detail and a great analytical approach to programming. I was impressed with the polished UI and UX considerations Karolis made while working with him. In addition to his solid programming skills, Karolis is a great communicator and easy to work with. I would recommend Karolis to anyone who is looking for a good react developer, he would be a true asset to your team.
Greg Stephenson
Founder · Netfront
I know Karolis was in his element in Reactjs: researching, delivering latest and greatest Reactjs UI in his work, spending free time rewriting Three.js games with React components, building web apps. Full of energy, efficient, right on the point. Looking forward to working (and having lunch time IT discussions) with you again!
Povilas Nanevičius
Mainframe Engineer · Rocket Software
I had the opportunity to work with Karolis from 2016 to 2019 while he was in Australia. I can attest he is a highly motivated, committed and responsible individual. Working with him gives you the confidence that work is going to be done and to the best standard. He would be a tremendous asset for you to hire or to get his services as a highly qualified professional.
Nando Mogollon
Founder & Director · BuilDigital
Karolis worked as a react developer with my UX team. He was instrumental in building and developing our design system, a first for the company. I found him to be highly skilled and knowledgeable and an expert in his field. He is a strong communicator and diligent in his work. I highly recommend Karolis and hope to work with him again in the future.
Orla Lewis
Product Design Manager · Irish Life
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Write to hello@kastproductions.com