Custom software development: ERP, internal systems and apps.

02 / 08

Integrations, automation and moving off legacy systems

Most of my projects depend on systems exchanging data on their own, so nobody has to retype it. These are the main things I connect and automate:

• The accounting software Pohoda, KROS, Money and ABRA Flexi through their APIs or XML import and export
• Microsoft 365 (Outlook, SharePoint, Teams) and Google Workspace (Gmail, Drive, Sheets)
• Online stores, carriers and other systems through an API, file imports and exports or, where the system allows it, directly through the database
• Automations in n8n, Make or Zapier when a low-code tool is enough, and custom code when it isn't
• Contracts, quotes and PDF documents generated from templates and system data, including electronic signatures
• Moving from an old system in Excel, Access or legacy PHP to a new web application, data included

03 / 08

Websites, design, SEO and cloud

Besides systems, I take care of what goes with them: the website your customers find you through, the interface design and running it all in the cloud.

• A custom company website that loads fast and reads well on a phone, with a form that saves every inquiry straight into your system
• SEO and GEO audits: optimising a website for Google and for AI search tools such as ChatGPT and Perplexity
• UI/UX design: the interface and a clickable prototype, even if someone else builds it
• An AI chatbot on your website that answers customers from your company's public information
• Cloud and DevOps: deployment on Google Cloud or Vercel, Docker and automated deployment (CI/CD)

04 / 08

Examples of my work at U.S. Steel Košice and DAU

I built internal systems and integrations at the steelmaker U.S. Steel Košice, where I worked part-time from 2022 to 2026. I was the only developer in my department, so I designed and built web portals and internal tools myself, from requirements to deployment, and then maintained them. I also managed databases and integrated systems across departments.

Through the AI agency Eturial, I wrote the security layer for the CRM and client portal of DAU, a Slovak tax and accounting firm: rules in the database that decide who can see and change which records. I also rebuilt the client portal and the dashboard.

05 / 08

Custom vs off-the-shelf software: when to build and when to buy

Custom software pays off when an off-the-shelf tool covers only part of your process and people do the rest by hand in spreadsheets and emails. If an off-the-shelf tool can handle almost everything, buy it and fill the gap with a single integration. That works out cheaper than development. If building your own wouldn't pay off, I'll tell you so at the consultation.

For accounting and payroll, I recommend sticking with off-the-shelf software whose vendor keeps it up to date with changes in the law, and building your own software around it. From 1 January 2027, VAT-registered businesses established in Slovakia must, with some exceptions, issue e-invoices to other businesses and legal entities in Slovakia, including the public sector. An e-invoice is a structured XML file that software can process automatically, so if you invoice from your own system, it has to be able to create e-invoices too. The obligation and its exceptions are set out in Section 85o of the Slovak VAT Act (in Slovak), and the Slovak Financial Administration gives an overview in English on its eInvoicing page.

Consider a system of your own if at least one of these applies:

• An off-the-shelf tool would force you to change or work around the process that sets you apart from your competitors
• The details of a single project are spread across several tools, and people retype them by hand from one to another
• Over a few years, licences for several tools and the work around them would cost you more than a system of your own, running costs included
• You need to connect systems that don't talk to each other on their own, such as an online store, carriers and accounting software

06 / 08

The technologies I build on, and why

I build systems in TypeScript with Next.js and React, and I store data in PostgreSQL or MySQL. These are widely used technologies with a large community and long-term support. Here's what that means for you in practice:

• Next.js, React and TypeScript: the application runs in the browser on a computer or a phone, and TypeScript catches many bugs before the code even runs
• Node.js: the server side, scheduled jobs and connections to other systems' APIs
• PostgreSQL or MySQL: proven relational databases that you can export your data from at any time
• Supabase: a database with user sign-in and Row Level Security rules that decide, for every record, who can see and change it. Through the AI agency Eturial, I wrote this kind of security layer for the CRM of the Slovak tax and accounting firm DAU and rebuilt its client portal and dashboards.
• Vercel or Google Cloud: the services the system runs on and through which new versions are deployed. I can set up the applications, the database and scheduled jobs on Google Cloud as code in Terraform and ship new versions to production automatically through CI/CD. A setup written as code can be reviewed and repeated exactly, without clicking through the cloud console by hand.
• Automated tests (Vitest, Playwright) for the parts where a bug would cost money, such as calculations and payment matching

07 / 08

How much does custom software development cost, and how does it work?

Projects start at around €500: that's what a single automation or a smaller tool costs, a few days of work. A system your company runs on every day, such as a CRM or another internal system, takes months to build, and I split the quote into parts so you can start with the one that helps you most. Running costs, meaning hosting and any AI model calls, range from tens of euros to the low hundreds a month.

Development has four steps. At a free consultation (30 to 60 minutes, online, in person or by phone), we work out whether custom development is worth it for you at all. Then you get a quote split into parts, each with its own price and delivery date. If you approve the whole quote or just some of its parts, I build a free prototype on a sample of your data, so you can check that it will work before you make a final decision. Only then do you place an order. Deployment, including integration with your existing systems, usually takes six to twelve weeks and ends with a handover that includes documentation and training.

You pay 20% when you order and the rest after handover. By default, I then run the system on my own accounts for a monthly fee, always fix its bugs for free and price new features separately. For moving the system to your own accounts and personal data protection, see how we work together.

08 / 08

Custom software from Košice for companies in Slovakia and abroad

I build software from Košice for companies all over Slovakia, in Czechia and abroad: we can meet in person in and around Košice, and I work with everyone else online. As an independent developer, I run each project myself from the first conversation to deployment, so you talk directly to the person who writes your software.

I completed both a bachelor's and a master's degree (Ing.) in informatics at the Faculty of Electrical Engineering and Informatics of TUKE, the Technical University of Košice. You'll find more about my experience and education on my About page.

The quickest way to start is to use the form at the bottom of this page to tell me which process slows you down today and which tools you use for it. I'll get back to you within eight hours. You can also book a 30-minute introductory call on Google Meet there, directly in the calendar.