Hi, I'mTomislav Sertic
Full-Stack Software Developer
Full-stack developer based in Zagreb ðŸ‡ðŸ‡·, with hands-on experience delivering enterprise-grade solutions for major international clients including Saudi Aramco, ESA, and THT.
My professional work centers on customizing and extending Archibus platforms — from SQL optimization and Java backend development to HTML/JS frontend interfaces. I specialize in modernizing legacy codebases by integrating React into existing enterprise systems — bridging established infrastructure with modern front-end frameworks.
Alongside enterprise work, I design, develop, and maintain client websites using Next.js and TypeScript — handling everything from initial build to server deployment and ongoing maintenance. I'm also actively exploring AI integration to build smarter, more automated applications.
Side Projects
These are my side hobbies: websites I build for friends, small jobs, scripts, and various experiments driven by personal curiosity.
My day-to-day enterprise work (Archibus / Aramco / ESA / THT) is under NDA, so I can't share it here. Click any card below to see details on what I can show.
Select a project from the list to see details.
About Me
Hello there.
I'm Tomislav Sertic, a full-stack developer from Zagreb, Croatia ðŸ‡ðŸ‡·, with hands-on experience delivering enterprise-grade solutions for major international clients including Saudi Aramco, ESA, and THT.
I'm driven by solving complex technical challenges, whether that means breathing new life into legacy systems or building modern applications from the ground up.
Technical Skills
Core Languages: Proficient in JavaScript/TypeScript and C#. Experienced with Python for scripting and automation tasks.
Web Development: Strong command of React and Next.js for building dynamic front-end experiences. Skilled in Node.js (Express) for backend services. Proficient with SCSS and Tailwind CSS.
API Development: Experienced in designing and building RESTful APIs using both Node.js and C# (.NET Core/ASP.NET).
Databases: Solid experience with relational databases (SQL) and NoSQL databases (MongoDB, Sanity, Firestore).
AI & Automation: Interested in leveraging AI models (cloud & local) for enhancing applications. Utilize Python for creating various automation scripts.
Tools & Design: Comfortable translating Figma designs into code and using Adobe Creative Suite when needed.
Professional Experience
Current Role: Software Developer at Arctis d.o.o, where I maintain and expand the Archibus IWMS platform, an enterprise system used by organisations managing thousands of buildings.
What I Actually Do: Customising and extending Archibus end-to-end, from SQL optimisation and Java backend work to HTML/JS frontend interfaces. A big part of the job is bridging the gap between legacy Java/SQL backends and modern React frontends, integrating React into established enterprise codebases.
Notable Clients: Saudi Aramco, the European Space Agency (ESA), THT, and other entities significantly more important than I am.
On the Side: I design, develop and maintain websites for clients using Next.js and TypeScript, handling everything from initial build to server deployment and ongoing maintenance. When I'm not doing that, I experiment with AI, because the robots are coming and I'd like to be on their good side.
Beyond the Keyboard
Balanced Life: I strive for balance. When I'm not coding, you'll find me spending quality time with my family and my loyal dog.
Active Pursuits: I'm an avid basketball player (Pregrada Barbari - CroHoops), enjoy cycling, exploring nature through hiking, and diving.
Mind Games: I also enjoy unwinding with a game of chess.
Connect: Curious about my offline adventures? Check out myInstagram.
Latest Blog Posts
Check out some of my recent thoughts and findings.
Building High-Performance Web APIs with C# Minimal APIs in .NET
Why Choose Minimal APIs?
Creating a 3D Rotating Cube with Three.js
Creating a 3D Rotating Cube with Three.js
Get In Touch
Interested in collaborating or have a question? Feel free to reach out. The best way to connect is via email or LinkedIn.