
Cautus Sistemi · software agency and venture builder
Bring us the problem,
not the specification.
We write the scope and the estimate, after a first call and at no charge.
Custom software development: business systems · web and mobile applications · webshops
Three ways we work together.
The engagement does not end at delivery. A system somebody opens every day has to grow with the business, so we stay with it after launch.
Build and maintain
We take on the build and keep running the system after launch, at an agreed level of support. Ownership of the code and the data is yours from day one.
Evolution Power Tools, Valens Medical, Agency CRM
Joint product
A product built together, where you bring the market and the domain knowledge and we bring the technology and the team. Ownership and revenue share are agreed in writing before anything starts.
For ideas that can live beyond one company
Our own products
We build and run our own products against real use rather than assumptions. That is why we know what a system needs after launch, not only up to it.
Products in production
Patrono
A system for running restaurants and cafés
Owner and manager see revenue, supplier invoices, food cost per dish and staff scheduling in one application. Staff get their own access, with their shifts, hours and leave requests. It runs in the browser and as an app on the App Store and Google Play, so the same data is there at the table and in the venue.
Patrono does not replace the systems a venue already runs. It connects to POS Sector and to the Croatian e-invoicing system, with several more integrations in preparation.
- Sector
- Hospitality
- Type
- Our own product
- Platform
- Web, iOS and Android
- Integrations
- POS Sector, e-invoicing, several more in preparation
- At Papoy
- several separate tools reduced to one application, opened by the owner and the staff alike

Klinika Hub
A system for private practices, integrated with the national health system
Patients book online, the doctor keeps the record and writes the findings, and prescriptions, referrals and insurance checks run through an integration with CEZIH, the Croatian national health information system. Billing to the public insurer and receipt fiscalisation sit in the same system.
- Sector
- Healthcare, private practices
- Type
- Our own product
- Platform
- Web, iOS and Android

Evolution Power Tools
A webshop for professional tools
The client already ran a physical store and a distribution business for metal, wood and concrete cutting tools. The webshop added a channel that works when the store is closed, with the official catalogue, card payment and delivery. Prices, promotions and stock are run by the client's own team from their admin, without us.
- Sector
- Tool retail
- Type
- Client project
- Starting point
- an existing store and distribution business
- What it added
- online sales alongside the store, with order growth
- Languages
- multilingual

Where we have already built.
Every industry has its hard part. These are the ones we have been through.
Hospitality and retail
Systems for restaurants, cafés and retail: point of sale integration, fiscalisation, revenue across locations and food cost. Built on the Patrono experience.
Read moreHealthcare
Systems for private practices, clinics and pharmacies: scheduling, records, national health system integration and patient data protection.
Read moreRetail and wholesale
Webshops with per customer pricing, delivery and payment integrations and a link to the warehouse. Built on the Evolution Power Tools and MedicaLife experience.
Read moreFinance and education
Mobile and web applications with user accounts, subscriptions and billing. Built on the Staxo experience: iOS, Android, accounting and automated reporting.
Read moreAgencies and services
Custom CRM, client reporting and automation of repeating work. Built on a system for an agency that runs delivery platforms for restaurants.
Read moreWhat we cover.
Architecture, design, development, infrastructure and measurement. Responsibility for the result stays in one place, without handing you between suppliers.
Development
Web application development, webshops, mobile app development for iPhone and Android, custom CRM development, AI automation and integrations into the systems you already run.
Design
Interface and user experience in house. For brand and visual identity we work with Spiffy Studio.
Visibility
SEO and optimisation for AI search, Google Business profile, and content written against the questions people actually type.
Measurement
We pick the analytics tool to fit the product and the questions it has to answer. We set up events and funnels, and the report is one the owner reads without an analyst.
Infrastructure
Google Cloud, Firebase, Microsoft Azure and Vercel. Monitoring, backups and upgrades after launch.
Strategy
What to build first, what to postpone and what never to build. Scope agreed before the budget is spent.
Design
Design is the foundation, not a phase.
Interface and user experience we do in house. For brand, visual identity and design systems we work with Spiffy Studio, so the product stands on a foundation that gets extended rather than rebuilt every other year.
product and graphic design partnerSigned by the studio
Product design
From research to a live version: user flows, information architecture, wireframes, interface and usability testing.
Design systems
Design that stays consistent over years and survives the growth of the product and the team.
Rapid prototyping
A clickable prototype that tests the idea before development starts.
Technologies and platforms we work with.
Microsoft Azure and Microsoft SQL Server, where that is the environment a client already runs.
Questions clients ask.
Do you work with clients outside Croatia?
Yes, and the timezone is why it works. We are in Central European Time, so the working day overlaps the whole EU and most of the UK. Documentation, tickets and calls are in English.
How do you invoice an EU client?
CAUTUS SISTEMI d.o.o. is a Croatian limited company with an EU VAT ID, so you get a regular EU invoice. For clients VAT-registered in another member state the reverse charge applies.
Who owns the code?
You do. Code, database and credentials are handed over, and handover documentation is part of delivery rather than something you have to negotiate at the end.
What does a project cost?
It follows scope. After a first call you get a written quote with scope, price and timeline. We write it ourselves and do not charge for it.
Custom software or an off the shelf platform?
An off the shelf platform is cheaper for as long as you fit inside it. Custom starts paying off when the platform forces you to change how you work, when you pay per seat so every new employee costs more, or when somebody retypes data between two tools every week.
Do we have to replace the systems we already run?
No. We connect to what you have. Patrono is the example: it does not issue receipts, it connects to the point of sale a venue already uses, so the rollout needs no new hardware. We do the same with accounting, warehouse and HR systems.
Do you take equity instead of fees?
Where the product makes sense beyond one company, yes. Instead of billing hours we take ownership and share revenue, while you bring the sector, the market and the first users. Terms are agreed in writing before anything starts.
Which industries have you built in?
Hospitality and retail, healthcare including national health system integration, retail and wholesale ecommerce, subscription products in finance and education, and agencies. Each has its own page with the specifics.
How we start
Scope, timeline and price agreed, then we build.
After the first call you get a written proposal with scope, timeline and price.
- 1CallAt no charge. Bring the problem, we write the scope.
- 2PhasesA delivery at the end of each, and regular progress reporting.
- 3ContractCode ownership, terms and confidentiality, before anything starts.
Or call directly: +385 99 6037 494
Project enquiry
Describe your project
We work with companies and institutions. We reply within 24 hours.
- 1We reply within 24 hours and arrange a time.
- 2An introductory call about the project, timeline and budget.
- 3A written proposal with scope, timeline and price.



