01Live
SMS-Proxy
Government messaging gateway
A secure SMS gateway routing citizen notifications for public-sector services — built for reliability, auditability and scale.
Full-stack developer · available for select work
Software that teams
trust in production.
I'm Sebastjan. I design and build secure, high-performance web products — from government messaging and identity systems to EV platforms and AI tools.
Environments I've built for
- Public sector
- Norwegian enterprise
- EV operators
- Own products
Selected work
Delivered, measured, running.
A cross-section of what I've shipped — public-sector infrastructure through to products I'm building now. The Pipette service app rounds out the recent list.
02Live
IAM Platform
Identity & access, Norwegian market
Identity lifecycle and single sign-on for Norwegian customers — building Novell IDM drivers, user provisioning and access policies with Access Manager.
03Live
EV Charging Platform
Fleet & driver management
A management web app for EV charging — fleets, drivers, sessions and billing, with Keycloak-based auth and access management. Delivered front to back.
04In progress
Charge Sim
Charging simulation engine
A simulation engine for EV charging networks, built ground-up to model stations, load and protocols.
05In progress
Hive
AI automation for companies
A platform that helps companies design and run AI-driven workflows. My current product focus.
hive.seba4.org ↗
06Live
Fastbreak
Board game companion
The web home for Fastbreak, a board game a friend is making. An Astro site — mobile-first, warm and fast.
fastbreakgame.com ↗
07Live
Creative Ad Builder
Drag-and-drop ad production at scale
A visual, drag-and-drop builder for producing interactive digital ad creatives — design once, then generate and adapt thousands of on-brand variations across formats and channels. Built for a leading ad-tech platform used by global brands.
“Sebastjan owned the platform and auth work end to end — frontend through to the .NET services and Keycloak — and made calls we never had to revisit. He communicates like a senior engineer and ships like one.”
How I help
Scoped, priced and delivered up front.
Product builds
End-to-end web apps, from empty repo to production. I own architecture, delivery and quality.
Secure systems
Identity, messaging and infrastructure where reliability and auditability are non-negotiable.
Rescue & scale
Inherited a slow or tangled codebase? I make it fast, stable and maintainable.
About
A developer who reduces your risk.
I've spent my career on systems where getting it wrong is expensive — government messaging, identity and access, EV infrastructure. I bring that same discipline to every build, in Vue, Angular, React, .NET and Rust.
s4Labs is where I work in the open: shipping products like Hive, helping launch Fastbreak, and partnering with a small number of teams each year.
Let's talk about your project.
Tell me what you're building. I reply to every serious enquiry within a day — and if I'm not the right fit, I'll tell you honestly.