Software systems for communication-heavy operations
We build VoIP and SMS platforms, CRM workflows, SaaS portals, billing modules, API integrations and dedicated internal systems for companies that need reliable communication and operational control.
How we work
Calm technology, useful systems, clear delivery
Our work connects business thinking with engineering discipline. We prefer clear architecture, maintainable code, practical integrations, and interfaces that people can use every day without friction.
Web applications
Company websites, portals, dashboards, and custom workflows built for long-term growth.
Business systems
ERP, CRM, invoicing, client accounts, and operational tools that fit real company processes.
Go REST APIs
Fast backend services, clean contracts, MySQL data models, and secure integrations.
VoIP and SMS
SIP, SMPP, HTTP messaging, telecom automation, routing, and platform support.
My technology journey
From early computers to building complete telecommunications systems
This is my personal story. It began with simple curiosity, and every stage grew from the one before it — from home computers and first programs, through networks and telecommunications, to the systems I build for businesses today.
Artur Januszczyk · founder of in4system
Computers become my passion
I started with home computers — the Atari 65XE, Commodore and ZX Spectrum. The Atari was also where I took my first steps in BASIC. I was fascinated not only by what appeared on the screen, but above all by how everything worked inside.
8-bit computers · BASIC · experimentationMy first 386 PC and the sound of a modem
In the 1990s I moved to PC architecture. My first 386, successive operating systems and dial-up internet opened up the world of networks, services and communication between computers.
PC architecture · systems · internetFrom assembly language to web applications
At university I organised my earlier experience and began developing my programming skills deliberately. I explored assembly language, C and C++, followed by Java, PHP and HTML — from low-level computer operation to building web applications.
Assembly · C/C++ · Java · PHP · HTMLLearning infrastructure from the inside
I worked in IT companies, for a local internet provider and a cable television operator. This is where I learned the practical side of infrastructure: networks, servers, Cisco equipment and services that must operate reliably every day.
Networks · servers · Cisco · infrastructureTelecommunications becomes my specialisation
A turning point for me was providing technical support for an operator-focused class 5 softswitch platform. Daily contact with live deployments connected my networking experience with IP telephony, routing, billing and real operator requirements.
VoIP · class 5 softswitch · technical supportI begin building my own solutions
While developing in4system, I began designing complete communications systems independently. I combined SIP, SMPP and APIs with business logic, routing, billing, monitoring and interfaces for operators and customers.
SIP · SMPP · REST APIs · routing · billingWeb, stores and integrations
Along the way I created dozens of websites, API integrations and WooCommerce implementations. Each project broadened my perspective to include sales, payments, customer service and back-office workflows.
Web · APIs · WooCommerce · automationFrom individual services to complete platforms
Today at in4system I bring telecommunications, backend services, data and usable interfaces together in complete operational platforms. Technology is not a goal in itself for me — it should simplify work, reduce manual steps and give a company control over its processes.
Telecom · CRM/ERP · SaaS · client portalsFuture is now
I am looking further ahead: towards practical AI integrations, automation and prototypes of my own edge devices. I am also interested in communications designed to withstand distance, latency and limited infrastructure — perhaps one day even interplanetary. Big ideas, however, begin with useful solutions built here and now.
AI · edge computing · hardware prototyping · future communicationsWhat matters to us
Clarity
Readable scope, honest estimates, and direct communication.
Responsibility
We think beyond launch and care about support, stability, and maintenance.
Fit
The solution should match your company, not force your company into a template.