Luka Korolija, Developer in Novi Sad, Vojvodina, Serbia
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Luka Korolija

Verified Expert  in Engineering

Software Developer

Novi Sad, Vojvodina, Serbia
Toptal Member Since
May 9, 2022

Luka is a highly accomplished full-stack developer known for building robust applications in the fintech, IoT, and insurance sectors. His skill set includes serving as a lead developer, building dashboards and storefronts, and constructing microservices with advanced permission management. With a strong focus on JavaScript projects, particularly utilizing TypeScript, Luka's preferred tech stack revolves around Next.js and NestJS, but he also loves Angular and Laravel.


Yara International
Node.js, React, NestJS, JavaScript, GraphQL, TypeScript, SQL...
Angular, Zeplin, TypeScript, Swagger, Responsive Web Design (RWD), CSS3, HTML5
SwissRe iptiQ
React, CSS, SCSS, Less, HTML, Amazon Web Services (AWS), Node.js, GraphQL...




Preferred Environment

MacOS, IntelliJ IDEA, Git, Ant Design, React, Next.js, SCSS, TypeScript

The most amazing...

...tool I've developed was a fully customizable privacy manager (GDPR and CCPA compliance) application that can be embedded on a site used by numerous sites.

Work Experience

Software Engineer

2023 - 2024
Yara International
  • Developed a NestJS microservice back end tailored to effectively support and complement the front-end functionalities.
  • Proposed technical concepts to address the challenges of migrating data between platforms, facilitating communication with external and internal teams to understand the constraints and parameters of the potential solution.
  • Contributed to defining the requirements for the technical proof of concept (POC), helping to clarify the scope of what was achievable within the given timeframe.
  • Utilized Jira for tracking and resolving bugs, as well as for implementing features. Additionally, complex processes and solutions were meticulously documented in Confluence for comprehensive clarity and future reference.
Technologies: Node.js, React, NestJS, JavaScript, GraphQL, TypeScript, SQL, Amazon Web Services (AWS), Kubernetes, Microservices, Microservices Architecture, CI/CD Pipelines

Senior Front-end Developer

2022 - 2023
  • Contributed to the growth and functionality of the Angular application by developing new features from scratch.
  • Collaborated with the designer to achieve a unified and pixel-perfect design across the application.
  • Collaborated with the back-end team to optimize data for seamless front end compatibility.
  • Independently developed features from scratch without a predefined design in situations where speed was paramount.
Technologies: Angular, Zeplin, TypeScript, Swagger, Responsive Web Design (RWD), CSS3, HTML5

Senior Full-stack Developer

2022 - 2023
SwissRe iptiQ
  • Maintained and developed new features for the GraphQL API.
  • Connected a bunch of microservices by utilizing resolvers in Apollo Server for Node.js.
  • Enhanced error logging by leveraging Grafana and Prometheus to effectively capture errors from the GraphQL API.
  • Developed a microservice that integrates Svix to consume events published by Kafka. This microservice enables partners and clients to consume the events.
  • Authored and upheld the documentation for the public API intended to be utilized by partner developers.
Technologies: React, CSS, SCSS, Less, HTML, Amazon Web Services (AWS), Node.js, GraphQL, Apollo, Prometheus, Grafana, GitLab, Svix, Kibana, CSS3, HTML5

Senior Full-stack Developer

2021 - 2022
Social Media Promotion Platform
  • Created a platform used to promote all creators' social platforms using Next.js for SEO.
  • Developed advanced filtering to find creators based on their qualities.
  • Set up the deployment process on Heroku with three environments (development stage and production).
  • Tracked and fixed issues using Jira as a reporting tool.
Technologies: JavaScript, React, Next.js, Firebase, Heroku, User Experience (UX), SCSS, Bootstrap, Front-end, TypeScript, Search Engine Optimization (SEO), WebApp, Full-stack Development, NoSQL, Full-stack, React Hooks, CSS, React Router, Redux, React Redux, Figma, Responsive Web Design (RWD), CSS3, HTML5

Senior Full-stack Developer

2020 - 2022
Online Ticketing Platform
  • Conducted initial mockups of the application, providing a clear vision of the project requirements and guiding subsequent development efforts.
  • Assumed responsibility for ticket creation, effectively managing the workload of team members through Jira, and ensuring efficient task allocation and progress tracking.
  • Authored comprehensive project documentation in Confluence, facilitating knowledge sharing and providing a valuable resource for the team.
  • Developed an innovative application that enables creators to create engaging events, fostering meaningful interactions between them and their fans.
Technologies: JavaScript, Laravel, Angular, MySQL, User Experience (UX), SCSS, Front-end, TypeScript, WebApp, SQL, Full-stack Development, Full-stack, PHP, CSS, GitHub, Figma, Responsive Web Design (RWD), CSS3, HTML5

Senior Full-stack Developer

2020 - 2022
Even Financial
  • Ensured seamless performance by maintaining and resolving bugs in the NestJS API and Next.js app.
  • Improved code organization and reusability by migrating components to Storybook during a comprehensive refactoring process.
  • Enhanced reliability and quality through the creation of thorough unit tests, significantly expanding the test coverage of the front-end application.
Technologies: Next.js, NestJS, Storybook, Ant Design, Blueprint, JavaScript, React, Node.js, SCSS, Front-end, TypeScript, WebApp, Full-stack Development, Full-stack, React Hooks, CSS, React Router, Redux, MongoDB, GitHub, React Redux, Figma, CSS3, HTML5

Full-stack Developer

2020 - 2021
  • Developed a dashboard, GDPR, and CCPA for the managers of a marketing company.
  • Implemented codebase refactoring, leveraging higher-order components to achieve design and functionality consistency.
  • Played a key role in maintaining and optimizing existing microservices.
  • Facilitated seamless onboarding of new team members, providing guidance and support to help them acclimate to the project environment.
  • Architected a new microservice from the ground up for efficient permission management.
Technologies: Angular, Node.js, Serverless, Amazon Web Services (AWS), JavaScript, Material Design, SCSS, Front-end, TypeScript, WebApp, Full-stack Development, NoSQL, Full-stack, CSS, AWS Lambda, Responsive Web Design (RWD), CSS3, HTML5, Amazon Cognito

Full-stack Developer and Product Owner

2018 - 2019
  • Spearheaded the design and development of a comprehensive CMS utilizing Laravel, enabling seamless content management and administration.
  • Leveraged Adobe XD to design and mock-up intuitive user flows for the webshop, ensuring a smooth and engaging shopping experience.
  • Constructed a versatile dashboard using Laravel Blade templates and Vue.js components, facilitating the seamless addition of entries, enhancing the storefront, and effectively showcasing the company's presentation.
  • Implemented a robust localization infrastructure that supported three languages, enabling the application to cater to a diverse user base.
Technologies: Vue, Laravel, Blade Templates, MySQL, SCSS, Bootstrap, JavaScript, TypeScript, Search Engine Optimization (SEO), WebApp, SQL, Full-stack Development, Full-stack, PHP, CSS, Bootstrap 4, Responsive Web Design (RWD), CSS3, HTML5

Spare Agricultural Parts Web Shop
A Laravel-based application that serves as both a web presence for your company and a webshop to showcase your entire product list. The application has been meticulously designed using Adobe XD, ensuring a visually appealing and user-friendly interface.

To bring the design to life, I utilized Laravel, Blade Templates, and Vue.js components on the front end. Laravel, a powerful PHP framework, provides a solid foundation for the application's back-end functionality, including routing, database management, and authentication. Blade Templates allow for efficient and modular code organization, enhancing the maintainability and scalability of the application.

By incorporating Vue.js components, I ensured a seamless and interactive user experience. Vue.js enables the creation of dynamic and responsive elements within the application, such as real-time product filtering, cart management, and smooth page transitions.

Overall, this Laravel-based app, developed with attention to design details and utilizing a combination of cutting-edge technologies, offers a compelling web presentation and a user-friendly webshop for your company's product list.

Event Management and Ticketing Website

I spearheaded the development of an event management and ticketing application, leveraging both Laravel and Angular frameworks. As the lead full-stack developer, my primary responsibility revolved around crafting the front-end using Angular and Ant Design.

With Angular, a powerful JavaScript framework, I created a robust and interactive user interface, ensuring seamless navigation and engaging user experiences. Ant Design, a popular UI library, enabled me to expedite the development process by providing a rich set of pre-designed components that align with modern design standards.

In addition to my development duties, I played a key role in onboarding a new team member. I effectively delegated some easier tasks and bug fixes to the new employee, ensuring efficient project progress and creating a supportive learning environment.

By combining the strengths of Laravel and Angular, we successfully built an efficient and feature-rich event management and ticketing application. This collaborative effort, focusing on the Angular front end and leveraging Ant Design, resulted in a user-friendly and visually appealing solution for seamless event organization and ticketing.

GDPR and CCPA Privacy Managers
As the front-end engineer, I took the lead in developing an Angular-based application to assist users in managing their privacy preferences and ensuring compliance with the GDPR and CCPA data protection regulations.

Working closely with the design team, I collaborated to enhance the design consistency and overall polish of the product. By aligning the application's visual elements, typography, color schemes, and layout, we achieved a cohesive and professional user interface.

Using Angular, a powerful JavaScript framework, I crafted an intuitive and user-friendly interface that allows users to easily set and modify their privacy preferences. Through well-designed forms, interactive components, and smooth transitions, we aimed to provide a seamless experience for users navigating the privacy settings.

The application prioritizes user control and transparency, enabling individuals to make informed decisions about their personal data and privacy. By adhering to the GDPR and CCPA regulations, we ensured that users' privacy rights were respected and their data was handled in a compliant manner.

Dashboard for a Digital Marketplace for Financial Service Companies
As the full-stack developer, I worked on both the Next.js and NestJS frameworks to develop a comprehensive dashboard for monitoring users and their activity.

On the front-end side, I utilized Next.js to build a responsive and user-friendly interface for the dashboard. Leveraging Next.js allowed for efficient server-side rendering and seamless navigation, ensuring a smooth user experience. I implemented dynamic components, data fetching, and interactive features to provide real-time insights into user activity.

Simultaneously, I also worked on the back-end using NestJS. Within the NestJS application, I focused on creating middleware that served as a crucial bridge between the front-end application and various APIs developed by the back-end team. This middleware facilitated the seamless integration of data and communication between the front-end and back-end components, enabling efficient data retrieval and updates for the dashboard.

Whitelabel API for an Insurance Company

I played a significant part in working on a Node.js Apollo Server that facilitated the seamless connection of numerous microservices through efficient resolvers, queries, and mutations. My responsibilities encompassed maintaining the API's stability while actively contributing to its enhancement. One notable area of focus was the improvement of error logging capabilities. I implemented robust mechanisms to ensure comprehensive error logging, allowing for efficient troubleshooting and issue resolution.

Building Management App
An Angular-based dashboard that provides an overview of buildings, companies, assets within the buildings, and real-time data. The real-time data is sent through MQTT to the back end and displayed on the front end, ensuring up-to-date information on the site.

Throughout the development process, I collaborated closely with the designer and the back-end team to ensure a pixel-perfect application. By closely working with the designer, I implemented the design elements and layouts with precision, creating a visually appealing and cohesive user interface.

Furthermore, in collaboration with the back-end team, I optimized the data sent from the back end to minimize the transformations required on the front end. This optimization ensures efficient and streamlined data delivery, enhancing the performance and responsiveness of the application.


JavaScript, TypeScript, PHP, CSS, HTML, SCSS, SQL, GraphQL, CSS3, HTML5, Less


Laravel, Angular, Next.js, Ant Design, Bootstrap, Redux, WebApp, Express.js, NestJS, Blueprint, Swagger


React, Node.js, React Router, React Redux, REST APIs, Vue


IntelliJ IDEA, Git, GitHub, Figma, GitLab, Webpack, Grafana, Kibana, Zeplin, Amazon Cognito


Search Engine Optimization (SEO), Responsive Web Design (RWD), Microservices, Microservices Architecture


Firebase, MacOS, Amazon Web Services (AWS), Heroku, AWS Lambda, Kubernetes


NoSQL, MySQL, MongoDB, PostgreSQL


Blade Templates, Bootstrap 4, Material Design, User Experience (UX), React Hooks, Front-end, Full-stack, Full-stack Development, Apollo, Web Development, Storybook, Back-end, Serverless, Gatsby, Prometheus, Svix, CI/CD Pipelines

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