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Your Technology Partner from Vienna

We build software that drives your business — and stay until it does.

We help businesses in Austria, Germany, and Switzerland grow faster with well-designed software and stay competitive long-term.

Free Consultation
30+
Solutions in Active Use
7
Years Longest Partnership
6+
Long-term Clients
Who We Work With

We're the right partner if…

Investing in the right technology today secures a lasting competitive edge. We work with businesses that understand this.

What Business Owners Hire Us For

So your business stays ahead technologically.

We make your business future-proof. With solutions that work today and scale tomorrow.

Sell more, online and offline

Sales systems that grow with your business. Multiple channels, multiple markets, automated processes.

Custom Online Shop
POS Systems
Marketplace Integration
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Automate processes

No more double work across different systems. We connect your tools into one seamless workflow.

ERP Integration
Automatic Invoicing
Order Reconciliation
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Expand into new markets safely

Expanding to Germany or Switzerland? We handle taxes, deposits, languages, and regulatory requirements.

EU Tax Compliance
Data Protection (GDPR)
Multilingual
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Custom digital products

From idea to finished application. Well-thought-out, scalable and with long-term support.

iPhone & Android
Web Applications
Industry Solutions
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Success Stories

Real projects. Real results.

From WhatsApp orders to millions in revenue. This is what happens when technology fits the business.

7 Years Partnership · Highlight

Ferhatovic: From WhatsApp Sales to €4M Annual Revenue

2018: A retailer selling goods via WhatsApp and Facebook Messenger. No shop, no system, no processes.

Today: A fully digitized business with online shop, custom app, automated purchasing, mobile point-of-sale, and restaurant checkout.

Ganze Geschichte lesenferhatovic.at
7+
Years Partner
2018
Sales via Messenger
2019
First Online Shop
2020
Upgraded Shop
2021
Custom App for Customers
2022
Inventory & Purchasing
2023
Mobile Point-of-Sale
2024
Restaurant Checkout
Partner since 2018

Vivacolor: From Paper Chaos to Automatic Payment Collection

Starting point: Paint retailer with B2B and B2C business. Prices had to be entered manually into 2-3 systems. POS and inventory were disconnected. Invoices were created weekly by hand. Late payments were only noticed weeks later.

Result: One central system for POS, online shop and inventory. Invoices are sent automatically after every delivery note, with QR code for quick payment. Result: over 80% of invoices paid on time. Prices, stock levels and orders all run from a single source.

Ganze Geschichtevivacolor.at
80%
On-time Payment
Digitization

Deinglas: Entire Business Digitized

Starting point: Manual processes in production, invoicing, customer communication. No central system.

Result: Custom online shop with glass configurator, production dashboard, automated invoicing and email. 5 systems connected in total.

Ganze Geschichtedeinglas.at
5
Systems Connected
Relaunch & Expansion

Sultan Drinks: Complete Relaunch with Inventory Management

Starting point: Outdated online shop, no inventory connection, manual order processing, expansion to Germany planned.

Result: New online shop, inventory management for order processing, automated deposits and VAT for Austria, Germany, and Bosnia.

Ganze Geschichtesultan-drinks.com
3
Markets Live

Sounds like what you're looking for?

Book a Free Consultation
How We Work

From first question to partnership.

Four steps. Clear results. No empty promises.

01

Initial Call

We listen. What's the real problem? Where are you losing time and money? 30 minutes, no commitment.

30 min
02

Analysis & Concept

We examine your processes, find quick improvements, and create a concrete plan with priorities.

1–2 Weeks
03

Implementation

Step-by-step development in short cycles. You see regular progress, not just presentations.

4–12 Weeks
04

Partnership

Launch is not the end. We stay involved: support, optimization, and continued development.

Ongoing
What Clients Say

Trust is built through results.

Feel free to ask us for additional reference contacts.

“We grew together. From Messenger orders to a digitized business with millions in revenue. Sandin was there every step of the way. When I have a problem, I call my Bruda. That was the case in 2018 and it still is today.”
Senadin Ferhatovic
Senadin Ferhatovic
Ferhatovic
“We've been working with Sandin since 2018. He rebuilt our entire business without a single day of downtime. When something's not right, I call and it's done. Simple as that.”
Samir Heralic
Samir Heralic
Vivagroup GmbH
“What convinced me about Sandin: he doesn't think in projects, he thinks in solutions. After the relaunch he didn't disappear. He kept optimizing, supported our expansion into new markets, and is still our first call when it comes to technology.”
Imran D. Mehic PhD, MBA
Imran D. Mehic PhD, MBA
Sultan Drinks
Why SADU

Developers who understand your business.

We understand the problems of business owners because we run one ourselves. And because we work deeply in our clients' businesses every day.

We immerse ourselves in your business

We manage online shops, inventory systems, and processes long-term. Not as an external agency, but as part of your team. We know your workflows, your customers, and your numbers.

One point of contact for everything

No back and forth between designer, developer, and project manager. You talk to one person who understands your business and takes responsibility.

Knows the rules in AT, DE & CH

Cash register requirements, data protection, cross-border taxes, deposit systems, labor law. We know the regulations and build them in from the start.

Artificial Intelligence

AI with substance, not buzzwords.

We use AI where it creates real value. And tell you honestly when it doesn't make sense.

Most businesses don't need their own AI. They need someone who understands where AI creates real value and where a simple, well-designed process is the better solution. That's exactly what we do.

Privacy-compliant AI systems

Custom models on European servers. Your data never leaves the EU.

Intelligent processes

Invoice recognition, order reconciliation, email sorting. Processes that handle themselves.

Choosing the right tools

Which tool for which purpose? We evaluate, test, and implement.

Honest assessment

Not everything needs AI. We tell you when a simple script is the better solution.

Sandin Dulić
Behind SADU

Sandin Dulić

Founder & Developer

I come from product development, including at Shpock and other Vienna tech companies. I've been working with my own clients since 2018, full-time with SADU since 2023. I support my clients long-term. Their shops, systems, and processes aren't projects to me, they're partnerships.

My clients appreciate that I speak their language: that of the business owner, not just the technician. I understand margins, payment flows, and regulatory requirements just as well as the technology behind them.

ViennaDE · EN · BS6+ Long-term Clients
Frequently Asked Questions

Answers to the questions we hear most.

Everything you need to know about SADU, how we work and what a partnership looks like — at a glance.

What does SADU Development actually do?

SADU Development e.U. is a Vienna-based technology partner that works with retail, service and manufacturing businesses in Austria, Germany and Switzerland over many years. We build and maintain online shops (Shopify, WooCommerce, MedusaJS, JTL-Shop), connect inventory management, accounting and point-of-sale into one end-to-end workflow, and develop custom software when off-the-shelf systems don't fit.

Which companies does SADU work with?

We're the right fit for owner-led retail, service and manufacturing businesses with roughly €500k to €10M in annual revenue. Our clients are not start-ups — they are established companies that have grown over years and see technology as an investment in their business, not a cost line. Industries where we have the deepest hands-on experience: beverage retail, specialty retail, tool retail, food retail, paints and coatings, and glass fabrication.

Which countries does SADU work in?

Our office is in Vienna. We serve clients in Austria, Germany and Switzerland and know the relevant regulations by heart: Austrian fiscal register requirements (RKSV), German deposit scheme (DPG), cross-border EU VAT and GDPR. Through our clients we are also active across the EU and in Bosnia.

How does a SADU engagement work?

In four steps: (1) a no-obligation 30-minute first call where we listen and identify the real problem, (2) analysis and concept with clear priorities within one to two weeks, (3) iterative delivery in short cycles over four to twelve weeks, (4) a long-term partnership after go-live with ongoing support and evolution. We don't work in one-off projects — we work over years.

Is SADU a pure Shopify agency?

No. Shopify is one important tool but only one of several. We build WooCommerce shops, custom MedusaJS systems (like Sultan Drinks or Deinglas) and JTL-Shop projects just as readily. The platform is chosen based on what the client business actually needs, not based on our preferences — and migrations between these platforms are core business for us.

How much experience does SADU have?

Founder Sandin Dulic has been building web and shop solutions for his own clients since 2012 — in parallel to full-time roles at Shpock, allabout apps and youniqx. SADU Development e.U. was formally registered as an Austrian sole proprietorship in November 2023 and has been operated 100% full-time ever since. Several current client partnerships have been running continuously since 2018 — the longest for more than seven years.

What does working with SADU cost?

We don't publish hourly rates or fixed price lists because every project is different. After the first call and a short analysis you get a clear written proposal with scope, timeline and price — transparent, with no hidden costs. The first call itself is free and without obligation.

Who will be my point of contact at SADU?

Sandin Dulic personally — from the first message through delivery to ongoing support. No hand-offs between project manager, designer and developer, no rotating account reps. He is backed by two developers in Bosnia and his wife in the Vienna back office.

Next Step

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+43 699 18 191 484hallo@sadu.atVienna, AustriaLinkedIn →
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