Cautus SistemiCautus Sistemi

Software development

Custom web application development.

SaaS platforms, webshops, dashboards and internal tools. We work in Next.js and React and carry an application from the first sketch to production, then onwards as it grows.

We reply within 24 hours.

Based in Zagreb, EU VAT registered, working with international clients.

What we build

A web application runs in the browser. Nobody installs anything, and you maintain one version in one place. That covers very different projects, so the first thing we do is work out which one you actually need.

  • SaaS platforms with subscriptions, user accounts and billing.
  • Webshops with a catalogue, cart, online payment and an admin panel.
  • Dashboards and internal tools that replace spreadsheets and manual steps.
  • Marketing and landing pages whose job is to bring in enquiries.

When a custom application pays off

A ready-made subscription platform is cheaper as long as your business fits inside it. A custom application pays off when the tool forces you to change the way you work. You can usually recognise that by one of these signs:

  • Someone retypes data from one tool into another every week.
  • You pay per user, so every new employee costs you more.
  • A key part of the business runs on an Excel spreadsheet that only one person understands.
  • You need to give customers or partners access, but only to their part of the data.

If none of this applies to you, we will tell you to take a ready-made platform, even when it means we do not get the work.

How a project runs

We start with a call, at no charge, about what the application has to do and who will use it. On that basis you get a written proposal with scope, timeline and price.

Development is iterative. We do not disappear for three months and return with a finished product: you see progress regularly on a staging URL, and your feedback goes in while changes are still cheap. When it is ready we deploy it and hand you the credentials.

What we have built

For Peloza d.o.o. we built the official Croatian webshop of the Evolution Power Tools brand. Shipping cost is calculated from the courier's real price list, and stock arrives from the warehouse POS system during the working day. Business customers see their own price list after signing in. The client's team manages prices and promotions from its own admin panel, without us. Read how we built it.

Patrono, our own product, is a web application for running a hospitality venue. It runs in the browser, so staff can open the shift schedule and checklists on their phones without installing anything, and the app on the App Store and Google Play is there for those who want it. At Papoy, a partner venue, the owner and the manager got back over 10 hours a week previously spent on administration.

The stack

We work in the same stack we use for our own products: Next.js and React with TypeScript on the front end, Node.js or Python on the back end, PostgreSQL or Firebase for data, Vercel or Google Cloud for hosting.

That choice is not fashion. Next.js renders on the server, so pages are fast and search engines read them properly, and TypeScript catches mistakes before your users do. Using one stack also means that in five years the application will not be maintained by someone meeting an exotic technology for the first time.

SEO and performance are part of the job

An application that loads slowly or that Google cannot see loses you users before anyone has tried it. That is why speed and visibility are part of every delivery: server rendering, optimised images, structured data for search engines and measurement of real performance after launch.

After launch

A web application is not a finished project, it is a product that lives. We offer a maintenance contract covering hosting, security updates and backups, and when a new feature is needed it is built by the team that built the application.

From the portfolio

Web applications we have built.

Evolution Power Tools, webshop

Webshop

Visit

Evolution Power Tools

The official Croatian webshop for Evolution Power Tools. Bilingual catalogue with search and product variants, Stripe checkout, shipping priced by weight and zone, and an admin panel for products, orders, promotions and enquiries.

Read the case study
Klinika Hub, saas platform

SaaS platform

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Klinika Hub

Clinic management platform with online booking, patient records and WhatsApp automation.

Patrono, restaurant management platform

Restaurant Management Platform

Visit

Patrono

Operations platform for a restaurant, in the browser and as an app on the App Store and Google Play. The owner sees where the place stands every day: revenue, costs and supplier invoices in one place, food cost per dish with margins, shift schedules staff open on their phones, and HACCP records ready for an inspection.

Read the case study

Questions

FAQ

How much does web application development cost?+

The price depends on scope: how many roles and screens the application has, which systems it connects to, whether it takes card payments and how much data has to be moved from the old system. A webshop on a ready-made base and a subscription platform are not the same order of magnitude. Describe the project in the enquiry form, and you get a written proposal with price and timeline after the first call, at no charge.

How long does a web application take?+

A simpler website or landing page is done in two to four weeks. A larger application such as a SaaS product, webshop or dashboard takes two to four months. The exact timeline comes out of the requirements analysis.

What does implementing a web application include?+

Implementation is everything that takes the application from the staging URL to its first real user: setting it up on a server, the domain and SSL, moving data from the old system, backups and measurement after launch. At the end we hand over access and documentation. If you have your own IT team, they take them over. If you do not, we keep running all of it under a maintenance contract.

Do we need a web app or a mobile app?+

If the application is opened at a desk or occasionally, the web is enough and cheaper: one version works on a computer and on a phone, with no app store release. A mobile app makes sense when users open it several times a day and on the move, or when the app itself is a product sold through the App Store and Google Play. For those cases see mobile app development.

Do you build webshops on a ready-made platform or custom?+

Both, depending on how much the webshop has to know about your business. For standard selling, a ready-made base is faster and cheaper. Custom pays off when the price depends on the customer, when shipping is calculated from your courier's price list, or when stock comes from a warehouse system you already have. That is how we built the Evolution Power Tools webshop.

We have an old application or website. Can you take it over?+

Yes. First we go through the code and the servers and tell you in writing what is worth keeping and what should be replaced. If the application changes, we move the data and redirect the old URLs, so your Google rankings are not lost. After that we run it under a maintenance contract, as if we had built it ourselves.

Where does the application run and where is the data?+

Usually on Vercel or Google Cloud, with a PostgreSQL or Firebase database, and the data is stored on European infrastructure. If your company already works in Microsoft Azure or on Microsoft SQL Server, we build the application there. Backups and updates are part of maintenance.

Can a web application charge a subscription?+

Yes. We build subscription SaaS platforms with Stripe: card payment with the strong customer authentication that European regulation requires, a trial period, cancellation and refunds. Subscription status is kept in one place, so the application and the reports always know who has paid.

How will we follow progress while the application is being built?+

On a staging URL, where you see the latest version. Development runs in agreed phases, with a delivery at the end of each, and we show progress on a weekly and monthly basis. We are in contact every day, so the scope can change while a change is still cheap.

Can we extend it later?+

Yes, that is how we build our own products. The application is structured so features can be added without breaking what already works, and the code and the credentials are yours.

Do you work with clients outside Croatia?+

Yes. We are based in Zagreb and build software for clients in Croatia and abroad. We invoice as a Croatian company with an EU VAT number.

Contact

Have an idea? Let's talk.

Tell us about the project. We reply within 24 hours. We write the scope and the estimate, after a first call and at no charge.