NJNikola Jovanović
Available for select projects

Nikola Jovanović · Full-stack web developer · Serbia

I craft useful things for the web.

Full-stack systems, thoughtful interfaces and data visualization—built with Laravel, FastAPI, Vue, React, TypeScript, D3.js and Three.js. More than a decade turning complex product problems into software people can rely on.

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Portrait of Nikola Jovanović

About

Full-stack developer with a product mindset

I'm a full-stack web developer with 10+ years of experience designing, building and scaling web applications — from Laravel and Python back ends to Vue, React and TypeScript front ends, with a soft spot for data visualization and 3D.

Most of my work has been long-term freelance partnerships: credit card platforms and fintech tools, multi-marketplace e-commerce, startup MVPs and scientific software — including Phylogeny.IO, a phylogenetic visualization tool published in Nucleic Acids Research. Lately I've been building a B2B SaaS product with FastAPI and React Three Fiber.

I care about clean, maintainable code, performance, and interfaces that get out of the way. Away from the keyboard I'm into film production and photography (I'm a licensed drone operator), martial arts and improv theatre.

Based in
Serbia (CET) · working remotely
Education
MSc, Computer Science & Information Technologies — Faculty of Electronic Engineering, Niš
Languages
Serbian (native), English (fluent), Romanian (basic)
Publication
“Interactive Web-Based Visualization of Phylogenetic Trees Using Phylogeny.IO”, Nucleic Acids Research, 2019

Skills

What I work with

Front-end

Expert
  • HTML5 & CSS3
  • Tailwind & Bootstrap
  • Accessibility (WCAG, ARIA)
  • jQuery

JavaScript & TypeScript

Proficient
  • Vue.js & Vuetify
  • React
  • TypeScript
  • Vite

Data Visualization & 3D

Proficient
  • D3.js
  • Three.js & React Three Fiber
  • Chart.js, ApexCharts & Highcharts

PHP

Proficient
  • Laravel
  • CodeIgniter
  • Legacy & custom frameworks

Python

Competent
  • FastAPI
  • Async SQLAlchemy & Alembic
  • Celery & Redis
  • Flask

APIs & Databases

Proficient
  • REST API design
  • MySQL & PostgreSQL
  • OAuth2 & JWT
  • Stripe & payment gateways
  • Marketplace APIs

AI Engineering

Proficient
  • OpenAI API, Claude & Gemini
  • Local models
  • RAG & semantic search
  • Structured extraction
  • Codex, GitHub Copilot & Claude Code

UI/UX & Design

Competent
  • Figma & Adobe XD
  • UX/UI & web design
  • Design systems

DevOps & Collaboration

Competent
  • Docker
  • GitHub Actions (CI/CD)
  • Nginx & Apache
  • DigitalOcean
  • Git, Agile/Scrum & Jira

Experience

Where I've worked

  1. Full-Stack Developer · Independent product

    2026 – Present

    Remote

    Building a B2B SaaS product for e-commerce, currently in development.

    • FastAPI back end with async SQLAlchemy, Alembic migrations, Celery/Redis background jobs and JWT auth, running in Docker.
    • React front end with an interactive 3D product viewer built on Three.js and React Three Fiber.
    • Brings patterns from years of Laravel work to idiomatic async Python, using AI-assisted development workflows.

    Python · FastAPI · React · Three.js · Docker

  2. Senior Software Engineer · Wiser Technology

    Nov 2025 – Aug 2026

    Niš, Serbia

    Part of a 5–8 person team modernizing a long-running, business-critical platform while it stays live for existing clients.

    • Refactored legacy business logic in a custom PHP framework while delivering new features and fixes.
    • Moved a mixed HTML/CSS and React front end toward a unified React shell.
    • Rebuilt the core layout and shared design-system components during a rebrand.

    PHP · MySQL · React

  3. Full-Stack Web Developer · Freelance

    May 2014 – Present

    Remote

    Long-term engagements with fintech, retail, startup and research clients — often owning the product end to end.

    • Fintech product for a startup

      2024 – Present

      An unreleased financial comparison and tracking product. I build the Laravel API and the Vue/Vuetify interfaces behind it — happy to talk through the work directly.

      Laravel · Vue · Vuetify · Tailwind · MySQL

    • Platforms for credit card companies

      2015 – 2024

      Customer onboarding portals, admin dashboards and REST APIs for card applications. Migrated legacy systems while preserving data integrity, and coordinated the companion mobile app's backend integration.

      Laravel · CodeIgniter · Vue · Highcharts

    • E-commerce for appliance parts retailers

      2016 – 2021

      Inventory and order logic, legacy modernization, and Walmart, eBay and Sears seller API integrations that keep listings in sync across marketplaces.

      Laravel · Vue · MySQL

    • Phylogeny.IO — phylogenetic tree visualization

      2015 – 2018

      Designed and built solo: dendrograms, radial trees and cladograms in D3.js, shared annotations for research teams, and an admin area for usage analytics. Published in Nucleic Acids Research (2019).

      Laravel · D3.js · MySQL

    Also: startup MVPs (a sports portfolio platform and a mediator networking app), genomic data visualization with Python, Vue and D3.js, a React web app with an ASP.NET API for a cruise company, plus dashboards and marketing sites.

  4. Web Developer · HTEC

    Jun 2013 – May 2014

    Niš, Serbia

    • Built an internal CMS with a strong focus on UI/UX.
    • Contributed to a medium-scale travel application in a multidisciplinary team.

    Laravel · MySQL · jQuery · Bootstrap

  5. Web Developer · EtelSoft

    Nov 2012 – Jun 2013

    Niš, Serbia

    • Worked on international web projects across front end and back end.
    • Contributed to UI/UX decisions and QA.

    CodeIgniter · MySQL · jQuery

Clients

What clients are saying

“Nikola is the ideal freelancer. He follows instructions well and the final deliverable is prompt and exceeds expectations. I recommend you choose Nikola for your project.”
Mark Halloran

Mark Halloran

President and Developer, Highermedia Inc. · United States / Germany

“Nikola and I worked together on many development projects. He has always been dependable and conscientious. He is very easy to communicate with, and discuss tasks and ideas. I wouldn't hesitate to recommend Nikola for any project.”
David Barrington

David Barrington

Lead Developer, Appliance Factory Parts · New Zealand

“Throughout the project Nikola has taken remarkable initiative in all aspects of design and implementation, often suggesting innovative solutions to problems as they emerged. He is hands down one of the best people I've worked with.”
Alexander Mikheyev

Alexander Mikheyev

Assistant Professor, OIST · Okinawa, Japan

“Nikola is an easy guy to work with. In-depth knowledge of D3.js. Excellent communication skills and fast to respond. 5 stars all round.”
Dr L. Heslop

Dr L. Heslop

CEO, Benchmark54 · Nottingham, United Kingdom

Contact

Let's work together

Have a project in mind, or just want to say hi? Send a message and I'll get back to you as soon as I can.

Or reach me directly