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Freelance / Contract / Startup Collaboration

From Idea to a Complete Digital Solution – Your Technical Partner for POC, MVP, and Production Systems

Software development, server infrastructure, IoT solutions, and AI integration – for startups, companies, and individuals who need reliable technical execution.

🚀 From the first idea to a working prototype, MVP, and production-ready system.
Free Consultation View Services

I work independently or as part of a team. Ideal for startups without a technical co-founder or teams that need an experienced engineer for critical development phases.

Services

1. Custom Software Development

I build solutions tailored to your project – not the other way around. From prototype to production.

  • Java (Maven): backend development for scalable applications
  • Python & C: embedded systems, automation, IoT, web services
  • .NET / C#: Windows desktop applications, Windows services
  • Kotlin & Java: Android app development

AI Integration

Artificial intelligence as a real feature of your product – not just a buzzword.

  • AI integration into existing or new applications
  • Custom models on your hardware or cloud
  • Process automation, intelligent assistants

2. Server & Network Solutions

In addition to development, I have hands-on experience in systems engineering and Linux administration, including DevOps practices.

  • Linux (Debian, CentOS): advanced administration
  • Truenas SCALE: on-prem storage server with Nextcloud
  • OPNsense / PFsense: network firewall and routing solutions
  • ISPConfig hosting: HTML, PHP, Python web applications with Let's Encrypt SSL certificates (HTTPS)
  • VPN server: private access to internal services
    • FTP server: accessible only via VPN connection
    • Mail server: SMTP/IMAP accessible only via VPN connection
  • KVM and Docker & Kubernetes: containerization and microservice orchestration
  • CI/CD pipelines: automated testing and deployment
  • Routers, VPN, NAS, backups, and network infrastructure

3. IoT & Hardware

  • IoT development (ESP32, STM32, Arduino, Raspberry Pi)
  • Sensor and actuator integration
  • Low-level C programming for electronics
  • Complete care for computers, servers, and network equipment

POC & MVP Development

POC – Proof of Concept

If you want to validate whether your idea is technically feasible, I prepare a Proof-of-Concept (POC):

  • rapid development of a basic technical solution
  • validation of key technologies and architecture
  • demonstration of feasibility
  • ideal for early-stage projects and investor preparation

MVP – Minimum Viable Product

An MVP is the fastest and most cost-effective way to turn your idea into a working product that can be tested on the market.

MVP Development Process

  • Idea & user analysis: defining the problem, users, and minimal feature set
  • Technical design: choosing optimal technologies (mobile, web, IoT, AI)
  • Rapid prototyping: building a working prototype for user or investor testing
  • Iterative development: improvements based on feedback
  • Scaling preparation: architecture ready for growth

Benefits of MVP

  • faster time-to-market
  • lower development cost
  • reduced risk
  • ideal for startups without in-house developers

AI Server & AI Workstation

Custom AI Server Deployment

For companies that want to run AI models locally and maintain full control over their data, I build and configure a custom AI server.

  • hardware selection (GPU, RAM, NVMe, cooling)
  • Linux installation (Debian, Ubuntu Server, CentOS)
  • CUDA, cuDNN, PyTorch, TensorFlow setup
  • KVM and Docker or Kubernetes for AI workloads
  • security, VPN access, environment isolation

Use cases: custom LLMs, computer vision, IoT + AI, algorithm development.

AI Workstation Development & Testing

For projects that are not yet ready for a full AI server or for rapid prototyping phases, I offer development and testing on a medium-sized AI workstation.

  • training medium-sized models (7B–13B LLMs, computer vision models, IoT AI)
  • testing prototypes before migrating to a larger server
  • algorithm development and optimization
  • IoT device and sensor simulations
  • fast iteration cycles for MVPs with AI components

Typical Configuration

  • 1× or 2× GPUs (e.g., Nvidia RTX or AMD)
  • 64–128 GB RAM
  • High‑speed NVMe SSD storage
  • Docker environment for isolated experiments

Selected Projects

A few examples where I combined software development, system engineering, IoT, and AI into real-world solutions.

Remote Office Access System

Designed and implemented a secure infrastructure for remote work, including VPN, authentication, server configuration, and access control.

Embedded Software for Electronics

Developed low-level C programs for hardware control, sensor communication, and real-time operation.

Android Applications on Google Play

Google Play Android Developer

Google Play Android developer with app for sending geolocation SMS messages.

Dockerized Microservices

Designed and deployed modular systems using Docker and Kubernetes, including CI/CD pipelines and production monitoring.

Patents

Selected patents and intellectual property developed by Sergej.

A PROCEDURE FOR IDENTIFYING THE CONTAINER AND DETERMINING THE WEIGHT OF THE FOODS ON THE HEATING PLATES INSTALLED ON THE SINGLE PANEL OF THE SMART COOKER

201700287 · Issued Oct 24, 2017
View patent

A PROCEDURE FOR REPORTING A GEOGRAPHICAL LOCATION WHEN ESTABLISHING ADIAL-UP CONNECTION BETWEEN THE PHONES

201700105 29/00 · G01C 21/00 · Issued Apr 18, 2017
View patent

A DEVICE AND A PROCEDURE FOR DETECTING THE STATE OF VEHICLE MOVEMENT BY TELEPHONE

201600106 21/00 · Issued Apr 28, 2016
View patent

ELECTRONIC DEVICE WITH A PROCEDURE OF INDEXATION OF GEOGRAPHIC LOCATION

201700105 19/00 · G06F 17/00 · Issued Oct 16, 2015
View patent

The Procedure of Sending, Receiving and Forwarding and Display Information on the Displays of Processing Weak Devices

201500187 29/00 · Issued Aug 17, 2015
View patent

Certifications

Professional Scrum Master I (PSM I) Oracle Certified Professional, Java SE 6 Programmer

Professional Scrum Master™ I (PSM I) - Scrum.org, Issued May 2024
Oracle Certified Professional, Java SE 6 Programmer - Oracle, Issued Dec 2012
Radioamater A classe, Klicni znak S50ST, April 2026

About Me

I am an electrical engineer and computer science engineer, radio amateur, software developer, and author of patent documentation and patent claims.

My work combines software engineering, electronics, system administration, artificial intelligence, and IoT — allowing me to cover the entire technical spectrum of a project, from hardware prototypes to complex software systems and AI integrations.

My Approach

  • clean, maintainable, and well‑structured code
  • clear and open communication
  • modern technologies and best practices
  • understanding of startup dynamics (POC, MVP, iterations, limited budgets)
  • focus on reliability, security, and scalability

AI as a Tool

I actively use AI tools to accelerate development, assist with code generation, documentation, and optimization — ensuring your project is delivered faster and with higher quality.

Contact

Do you have a project that needs technical execution? I’m happy to listen to your ideas and prepare a non‑binding offer — from one‑time projects to long‑term collaboration.

  • Email:
  • Location: Kranj, Slovenia
  • Radioamater: callsign S50ST
  • Collaboration: freelance, project‑based, or long‑term technical partnership