Open to new roles and projects

Hi, I'm Emil.
I build fast, scalable interfaces for the web.

Senior Frontend Engineer with 7+ years of experience crafting React & TypeScript applications across SaaS and iGaming products, from real-time back-office tools to AI-powered invoicing.

2019 · · · today

Let's work together Download CV
  • Pančevo, Serbia · Remote (CET)
Years of experience
7+
Product domains
SaaS · iGaming
Core stack
React · TS
Teams across
Serbia · Iceland
Portrait of Emil Bisak

[01] About

Engineering interfaces that stay fast as they grow.

I'm a senior frontend engineer with a strong focus on reusable architecture, performance optimization and data-heavy interfaces. I enjoy the hard parts of the frontend: real-time workflows, complex state and component systems that the whole team can build on.

I've spent years collaborating with product, design, backend and QA teams across Serbia and Iceland, and I care about clean, maintainable code, thoughtful code reviews and helping new teammates get up to speed.

  • Performance optimization
  • Reusable component architecture
  • Real-time & data-heavy UIs
  • Clean, maintainable code
  • Cross-functional collaboration
  • Mentoring & code reviews

[02] Experience

Where I've been building.

  1. Oct 2025 - Present Current

    Senior Frontend Engineer @ Freelance

    React + TypeScript admin panel for an iGaming platform, supporting back-office and operational workflows.

    • Develop and maintain admin panel features across back-office and operational modules, including the real-time tooling.
    • Work with product, design, backend and QA to ship stable, user-friendly internal tools.
    • Keep code quality up through code reviews, testing and modern frontend practices.
    • React
    • TypeScript
    • WebSocket
    • RTK Query
    • Vite
  2. May 2019 - Mar 2025 ~6 years

    Frontend Developer @ Unimaze Software

    React + TypeScript SaaS e-invoicing platform used in financial and accounting workflows.

    • Shipped features across the product for nearly six years, built on modular, reusable UI components.
    • Worked on the AI-powered invoice reader, the move from Redux to RTK Query and XSLT / Adaptive Cards document generation. More in Selected work.
    • Worked with distributed teams in Serbia and Iceland in Agile sprints, handling code reviews, debugging, onboarding and mentoring.
    • React
    • TypeScript
    • Redux
    • RTK Query
    • XSLT
    • Adaptive Cards

[03] Tech stack

Tools I reach for.

Core

  • React
  • TypeScript
  • Next.js
  • JavaScript (ES6+)
  • HTML5
  • CSS3

State & data

  • Redux
  • RTK Query
  • Context API
  • REST APIs
  • WebSocket

Styling & UI

  • Responsive design
  • Sass
  • Ant Design
  • Material UI
  • Bootstrap

Build & tooling

  • Vite
  • Webpack
  • npm
  • Git
  • Bitbucket

Quality

  • Jest
  • Cross-browser testing
  • Code reviews

Documents & formats

  • JSON
  • XML
  • XSL / XSLT
  • Adaptive Cards

Collaboration

  • Agile / Scrum
  • Jira
  • Figma

[04] Selected work

Things I've built in production.

Since 2019 my work has lived in private, client-owned codebases, so there are no screenshots or repos here. I'm happy to walk through any of it in a conversation.

Unimaze Software · SaaS e-invoicing

AI-powered invoice reader

Users upload an invoice and AI fills in the fields. The hard part was the workflow around it: automation people can still check and correct.

  • Built the invoice upload flow and the view of the data AI recognized.
  • Let users review and manually correct any field before the invoice moves on to processing.
  • Designed one clear flow that combines automatic extraction with manual checks for when recognition isn't accurate.
  • React
  • TypeScript
  • AI feature UI

Freelance · iGaming back office

Real-time admin panel

Back-office and operational tools where data changes constantly and nobody should have to hit refresh.

  • Tables, filters, forms and management features across several admin modules.
  • Live updates over WebSockets for data that has to stay current in real time.
  • Tuned rendering, state handling and responsiveness for data-heavy views with frequent updates.
  • Extended the shared component system with reusable components and common patterns, so modules stay consistent and easier to maintain.
  • React
  • TypeScript
  • WebSocket
  • RTK Query

Unimaze Software · Frontend architecture

Redux to RTK Query migration

Make API communication and server data simpler and more consistent, without rewriting a running product.

  • Moved existing Redux flows to RTK Query step by step instead of in one big rewrite.
  • Cut boilerplate and simplified data fetching and caching in the migrated parts.
  • Modernized how the frontend talks to the APIs.
  • Redux
  • RTK Query
  • REST APIs

Unimaze Software · Documents & email

Invoice rendering and email templates

Generate invoices and emails from application data instead of hand-building every format as its own frontend feature.

  • XSLT stylesheets that render invoices dynamically and produce structured documents from invoice data.
  • An email template system on Microsoft Adaptive Cards for dynamic transactional emails.
  • XSLT
  • XML
  • Adaptive Cards

[05] Education

Where I learned the craft.

Largely self-taught. I learned frontend on my own and through intensive courses, then went straight into production work in 2019.

  • Oct 2018 - Jan 2019

    Škola koda

    React, Redux & React Native

  • Apr - Jun 2018

    BIT, Belgrade Institute of Technology

    Intensive 10-week (400 h) bootcamp, JavaScript and React

  • Dec 2017 - Mar 2018

    Krojačeva škola

    8-week (160 h) frontend developer course

[06] Languages

Languages I speak.

  • SerbianNative
  • EnglishProfessional
  • SlovakAdvanced
  • HungarianBeginner

[07] Contact

Have a product that needs a great frontend?

Whether it's a freelance project or a full-time role, drop me a line and I'll get back to you soon.

bisak.emil@gmail.com