Services
Custom web applications and Kotlin backend from a freelance developer
I am a freelance developer based in Hradec Králové, Czechia, working as a backend developer and web developer. I build backends in Kotlin and Java, web applications in React and Next.js and AI-driven features to order, and I handle deployment and support after launch. Each service below links to a project where you can check how I work.
What do I offer?
As a freelance programmer and backend developer from Hradec Králové I offer four services: backend development in Kotlin, web app development in React and Next.js, AI and data, and DevOps and maintenance. I back every service with more than 8 years of experience and with projects I have already delivered and put into production.
I build backends on Kotlin, Java and Spring Boot with Kafka, GraphQL and PostgreSQL. As a web developer I deliver web applications in React, Next.js and TypeScript. I deploy them with Docker and keep looking after them once they are live, so one person covers the whole path from design to operations.
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Backend development
I design and build scalable backend systems and microservices that handle complex, high-throughput workloads reliably.
In the ELSE LOOK project I built a reactive Kotlin GraphQL backend: Spring WebFlux over R2DBC PostgreSQL, queries through jOOQ, a schema versioned with Flyway migrations and scheduled jobs guarded by ShedLock. It includes an integration with the Eurobydlení real-estate portal, media storage on S3, transactional e-mails and Sentry monitoring. I also work with Java, Spring Boot, Kafka and Redis. I design and build the API, the data model and the deployment so the system handles traffic and further growth.
See project: ELSE LOOK
Web app development
I build fast, modern web applications end to end — from React/Next.js frontends to the APIs and infrastructure behind them.
I build websites and web applications from the data model to deployment. FYSA is a bilingual site on Next.js 16 with React 19, TypeScript, next-intl and a contact form handled by a Server Action. For the HC Čestice hockey club I migrated a legacy website to Payload CMS 3 running inside Next.js, including the whole archive and the original URLs, so the migration cost no SEO. I care about speed, accessibility and SEO from day one.
See project: FYSA, HC Čestice
AI & data
I explore and apply AI and deep learning to real problems, including published work on computer vision, and help teams add AI-driven features to their products.
I work with deep learning and computer vision, including published work in the field, and add AI-driven features to products. On the data side I wrote Statement Analyzer, a desktop app (Electron, React, TypeScript) for analysing ČSOB CSV statements. It offers import with transaction de-duplication, a dashboard with categories and balance history, budgets and recurring-payment detection. The data stays local on the user's computer.
See project: Statement Analyzer
DevOps & maintenance
I set up CI/CD, containerized deployments and monitoring, and keep existing systems running smoothly with ongoing support.
I treat deployment and operations as part of development. The 4Watty band site runs Next.js and Payload CMS in Docker with media on S3, GitHub Actions handling build and deploy and Sentry reporting errors. This website has a Docker standalone build, GitHub Actions publishing to ghcr.io and a Coolify deployment. I also work with ArgoCD, Grafana and Kibana and provide maintenance and support after launch.
See project: 4Watty, lukaskopecky.cz
How we work together
The collaboration has a clear structure, so you always know which phase the project is in. There is no long approval chain: you talk directly to me.
1. First contact
You send me a few lines about your project and goals through the contact form or by e-mail. We set up a call to go over the details.
2. Proposal and estimate
After the call I follow up with a recommended approach and a timeline estimate. I size the scope and the technology to the needs of the project.
3. Development in stages
I break the work into clear milestones and keep you updated throughout. I can also take over and improve an existing codebase, fix bugs or modernize the stack.
4. Support after launch
After deployment I provide monitoring, maintenance, fixes and improvements as needed, so the application keeps running reliably.
Let's talk about your project!
