Nikola is available for hire

Nikola Knežević

Verified Expert in Engineering

Software Developer

Novi Sad, Vojvodina, Serbia

Toptal member since January 29, 2019

Expertise

Front-end Web Development Full-stack WordPress Development Integration Chatbot Development JavaScript CSS Git REST API PHP Laravel React.js jQuery

Bio

Writing code since the age of ten, Nikola has been passionate about technology, and learning new things has led him to become a cutting-edge developer. He loves solving complex problems with maintainable and scalable code. Over the years, Nikola has gained a lot of valuable skills and experience working with teams of all sizes and learning the value of good teamwork.

Portfolio

Eqho AI

Python, ChatGPT, Claude, Twilio, FastAPI, Google Cloud Platform (GCP)...

Vroom

Vue, Vuex, React, Next.js, Go, Node.js, Amazon DynamoDB...

Volvo R&D Center

HTML, CSS, TypeScript, JavaScript, React, Redux, Angular, GraphQL, Node.js...

Experience

JavaScript - 10 years
HTML - 10 years
CSS - 10 years
Node.js - 6 years
React - 6 years
Next.js - 5 years
PostgreSQL - 4 years
Go - 2 years

Availability

Part-time

Preferred Environment

Jira, GitHub, MacOS, JetBrains

The most amazing...

...thing I've created is a tool that appraised—and bought—more than 5,000 vehicles within a few minutes.

Work Experience

Director of Engineering

2023 - 2024

Eqho AI

Directed engineering efforts, focusing on core service and logic development for optimal performance.
Led the implementation of speech-to-text and text-to-speech technologies, enhancing user interaction capabilities.
Designed a performance-first architecture, prioritizing speed and scalability.
Conducted technology research and development to drive innovation and keep solutions cutting-edge.

Technologies: Python, ChatGPT, Claude, Twilio, FastAPI, Google Cloud Platform (GCP), LangChain, LangGraph, LangSmith, Large Language Models (LLMs), Deepgram, ElevenLabs Solutions, Git, REST APIs, Automated Testing, Docker, Architecture, WebSockets, Full-stack, Tailwind CSS, Redis, APIs, Artificial Intelligence (AI), Generative Artificial Intelligence (GenAI), Single-page Applications (SPAs), Web Development, Chatbots, OpenAI API, Integration, Zendesk API, Zendesk

Senior Software Engineer

2021 - 2024

Vroom

Architected and developed a white-label widget-like application that is used on more than 50 major websites in the automotive industry.
Built a custom drag-and-drop CMS with a dashboard, integration with analytics services, AB tests, reporting, role system, and much more.
Developed an application for inter-company inventory sync and bulk appraisal and acquisition.

Technologies: Vue, Vuex, React, Next.js, Go, Node.js, Amazon DynamoDB, Amazon Web Services (AWS), DocumentDB, Amazon S3 (AWS S3), PostgreSQL, Front-end, User Experience (UX), User Interface (UI), Firebase, Git, REST APIs, Automated Testing, Docker, Express.js, Architecture, React Native, Mapbox, WebSockets, Full-stack, Tailwind CSS, Redis, WordPress Plugins, APIs, Artificial Intelligence (AI), Alpine.js, Laravel Livewire, TALL Stack, Single-page Applications (SPAs), Inertia, Web Development, Integration

Software Consultant

2022 - 2023

Volvo R&D Center

Developed a micro-frontend system using module federation to unify multiple applications under a single UI.
Established an internal UI component library with implementation-agnostic theming, compatible with both CSS Modules and CSS-in-JS.
Migrated legacy applications from Webpack v4 to v5, enhancing performance and compatibility.
Improved TypeScript integration across codebases for better type safety and reliability.
Enforced contribution, commit, and test conventions to boost code quality and team efficiency.

Technologies: HTML, CSS, TypeScript, JavaScript, React, Redux, Angular, GraphQL, Node.js, Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Docker, Express.js, Architecture, Full-stack, APIs, Single-page Applications (SPAs), Web Development, Integration

Software Engineer

2021 - 2023

Juno Medical

Developed a public website, clinician portal, and patient portal with robust authentication and authorization.
Led major framework updates and migrated styling from Bootstrap to Chakra-UI for a modern, cohesive design.
Built an internal video appointments platform using Twilio, enhancing remote consultation capabilities.
Created a comprehensive reporting system and membership management tools.
Designed an appointment scheduling and availability system, streamlining booking processes for users.

Technologies: Node.js, Next.js, React, Apollo, React Apollo, GraphQL, Chakra UI, Twilio, PostgreSQL, Prisma, Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Docker, Express.js, Architecture, React Native, WebSockets, Full-stack, Tailwind CSS, HIPAA Compliance, APIs, Single-page Applications (SPAs), Web Development, Integration

Software Engineer

2019 - 2021

Casper Sleep Inc

Developed an internal UI library for consistent and reusable components across projects.
Integrated Contentful CMS to streamline content management and updates.
Created a custom WordPress theme for the company blog, enhancing brand alignment.
Built a web shop, optimizing the online shopping experience for customers.

Technologies: JavaScript, ECMAScript (ES6), CSS, Redux, React, Next.js, Content Management Systems (CMS), Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Docker, Architecture, Full-stack, WordPress Plugins, APIs, WordPress Themes, Single-page Applications (SPAs), Web Development, Integration

CTO

2017 - 2021

Decem

Set up the company architectures, coding standards, platforms, and processes.
Architected and oversaw the development of internal tools and software for payroll, presence, clients relations, and deployment management.
Communicated directly with clients in all stages, from initial negotiations to software delivery and ongoing maintenance.
Developed software in the field of company management and automatization, data visualization, eCommerce, transportation and delivery, blockchain, library development, mobile development, and much more.
Organized learning programs and personally mentored interns and younger colleagues.
Presented the company as a speaker at conferences and meetups.

Technologies: D3.js, jQuery, Node.js, Laravel, Vue, GreenSock, Sass, React, WordPress, Next.js, iOS, Android, IT Management, Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Docker, Express.js, Architecture, React Native, Mapbox, WebSockets, Full-stack, Tailwind CSS, Redis, WordPress Plugins, APIs, WordPress Themes, Single-page Applications (SPAs), Angular 2, Web Development, Integration

Software Engineer

2018 - 2020

Freelance

Worked in fields of data visualization, eCommerce, CMS optimization, front-end (mostly React), and back-end (mostly Laravel) development.
Managed clients, communication, delivery, and deployments personally.
Provided a few mentoring sessions and tech talks in local IT companies.

Technologies: React, Laravel, D3.js, WordPress, WooCommerce, Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Docker, Full-stack, WordPress Plugins, APIs, WordPress Themes, Single-page Applications (SPAs), Angular 2, Web Development, Integration

Software Engineer

2016 - 2017

NTH AG

Constructed a syncing system between multiple mail servers.
Built a SPA access control system for Spring Framework.
Developed real-time communication on top of Spring platform.
Organized Java workshops and introduced new development standards.
Created documentation for a custom front-end framework based on KendoUI.

Technologies: MySQL, jQuery, Kendo UI, Spring, Java, Git, REST APIs, Automated Testing, Architecture, Full-stack, APIs, Web Development, Integration

Lead Software Engineer

2014 - 2016

Cherry Studios

Constructed a game engine for Apache Cordova which enabled a cross-platform mobile game development.
Bootstrapped the company's development and QA standards.
Architected and oversaw the development of the engine for Android development. The engine was later used for the development of more than 50 apps.

Technologies: HTML, CSS, Cordova, LibGDX, Java, Front-end, User Experience (UX), User Interface (UI), Git, REST APIs, Automated Testing, Architecture, Full-stack, APIs, Web Development, Integration

Experience

Poštanski Broj

https://www.postanskibroj.rs/

I led the development of a Serbian platform for tracking and searching postal codes and companies. We implemented a solution in Laravel with Vue.js support on the front end and Algolia for real-time full-text search capabilities.

BalkanINFO

https://www.balkaninfo.rs/

Here, I developed an online platform for a regional journalism company. The platform includes online news, a webshop, a video management system, and polls.

The entire platform is built on WordPress. I built a theme and several plugins for YouTube synchronization, pools, and an Ajax post grid system.

Cogivi

For this project, I worked on all aspects of the Cogivi website, including back-end admin facilities and a great front end. Working with Cogivi was an exacting challenge, pixel-perfect designs needed to be implemented but with no perceptible loss of performance.

The back end was built in Node.js, and the front end started in Angular version 5 and evolved up to 7.

Inner Connection Coach

I implemented an awesomely designed website for a coaching agency in the USA. The main challenge was the implementation of unusual rounded corners and responsiveness of it.

I developed the solution in PHP, Sass, GreenSock, and ScrollMagic.

Skech

Here, I created a website for a local design company. It involved an extremely challenging front-end problem because of complex designs and animation requirements.

I implemented the solution in fullPage.js, Navigo, jQuery, and PlainCSS.

Patometry

In a research phase of hybrid mobile development, my team and I approached creating a game in Unity engine. The game was created for testing purposes but ended pretty well and populated at some point. I was a lead developer.

Education

2017 - 2020

Bachelor of Science (BSc) Degree in Computer Science

University of Novi Sad, Faculty of Sciences - Novi Sad, Serbia

Skills

Libraries/APIs

React, jQuery, Node.js, REST APIs, OpenAI API, Zendesk API, Vue, Inertia, D3.js, ScrollMagic, Vuex, Vue 2, YouTube API

Tools

Git, GitLab, GitHub, Jira, GreenSock, Trello, CKEditor, JetBrains, React Apollo, Prisma, ChatGPT, Claude

Languages

JavaScript, PHP, HTML, CSS, TypeScript, Python, Sass, SCSS, Go, Java, C#, GraphQL, ECMAScript (ES6)

Frameworks

Laravel, Redux, Next.js, Express.js, Tailwind CSS, Laravel Livewire, Angular 2, Angular, React Native, Alpine.js, Spring, Kendo UI, LibGDX, Unity, LangGraph

Paradigms

Functional Reactive Programming, Object-oriented Programming (OOP), Automated Testing, HIPAA Compliance

Platforms

WordPress, Zendesk, GreenSock Animation Platform (GSAP), iOS, Docker, Mapbox, Visual Studio Code (VS Code), Android, Amazon Web Services (AWS), Algolia, MacOS, WooCommerce, Twilio, Google Cloud Platform (GCP), LangSmith, Firebase

Storage

Redis, MySQL, MongoDB, PostgreSQL, Amazon DynamoDB, Amazon S3 (AWS S3), SQLite

Other

Styled-components, Front-end, User Experience (UX), User Interface (UI), Architecture, WebSockets, Full-stack, WordPress Plugins, APIs, WordPress Themes, Generative Artificial Intelligence (GenAI), TALL Stack, Single-page Applications (SPAs), Web Development, Chatbots, Integration, Artificial Intelligence (AI), Cordova, IT Management, DocumentDB, HTML5 Animations, Scroll Animations, Content Management Systems (CMS), Apollo, Chakra UI, FastAPI, LangChain, Large Language Models (LLMs), Deepgram, ElevenLabs Solutions

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring