Sergej Kurbanov, Developer in Prague, Czech Republic
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Sergej Kurbanov

Verified Expert  in Engineering

Software Developer

Prague, Czech Republic
Toptal Member Since
December 9, 2019

Sergej is a full-stack developer who brings innovation and growth to the table with almost seven years of experience in building scalable platforms and feature-rich applications. From building his own AI-driven SaaS product to coaching 150+ students to become junior React developers, Sergej's engaging approach and dedication to staying ahead of the curve make him an invaluable asset to any project or team.


Personal Project
Next.js, Supabase, OpenAI, React, Tailwind CSS, TypeScript, Stripe...
Freelance Client
JavaScript, Node.js, Prismic, Google Apps Script, Google API, Slack API...
React, CSS, HTML, JavaScript, Team Leadership, Software Architecture...




Preferred Environment

Node.js, Git, Visual Studio Code (VS Code), MacOS

The most amazing...

...product I have solo developed was an innovative SaaS product for personalized, AI-generated recipes and meal plans called Recipe Smarter.

Work Experience

Full-stack Developer

2023 - PRESENT
Personal Project
  • Architected and integrated the app's technology stack using serverless libraries like Supabase and Vercel. Selected and implemented ideal technologies to optimize performance, reliability, and security, ensuring a seamless user experience.
  • Developed and improved the app through user testing. Used AI (GPT) technology to generate recipes that meet user preferences and dietary requirements and continuously improved the app through user testing and feedback to enhance the user experience.
  • Designed the application's UI/UX. Developed an intuitive and visually appealing design to enhance user experience and ease of use.
  • Developed and executed successful SEO and analytics strategies to enhance the app's visibility and drive traffic. Regularly analyzed page insights and user behavior data to fine-tune marketing efforts.
Technologies: Next.js, Supabase, OpenAI, React, Tailwind CSS, TypeScript, Stripe, OpenAI GPT-3 API, Architecture, OpenAI GPT-4 API, Software Architecture, ChatGPT, Python, Artificial Intelligence (AI), Pinecone, GPT, PostgreSQL, Generative Pre-trained Transformers (GPT), APIs, Cloudflare, Prisma, Back-end, JSON

Full-stack JavaScript Developer

2020 - PRESENT
Freelance Client
  • Implemented a flow that allows users to use natural language to chat with uploaded PDFs, get answers to questions, or discuss anything from the documents. I integrated the Pinecone vector database, OpenAI's embeddings, and Langchain with a React app.
  • Streamlined a company's workflow by simplifying their Google services flow, turning several into more practical and easy-to-use solutions, tools, and integrations.
  • Transformed business ideas into technical solutions. Created products and features that increased productivity presented new possibilities and reduced manual processes.
  • Developed a Slack chatbot integrating Google's Dialogflow platform, which resulted in a bot that smoothly leads users through conversations while collecting relevant data points.
  • Redesigned a front-end application fully, building on an existing system. Created dozens of flexible CMS components, allowing designers and editors to focus on creating new content and cutting down the need for developer time by a large portion.
  • Built an image processing tool, compositing input images with various background images and outputting Google Slides presentations for rapid design prototyping.
  • Created an interactive Slack workflow for downloading media from user-supplied links. It processed tens to hundreds of video and audio files daily, delivering them to a storage platform after applying various edits and tags.
  • Developed a robust React dashboard system to visualize stock trading data using Plotly.js. Wrote and managed data endpoints in Node.js utilizing GraphQL.
Technologies: JavaScript, Node.js, Prismic, Google Apps Script, Google API, Slack API, Slackbot, Vue, Dialogflow, ImageMagick, FFmpeg, Backblaze B2, Iconic, Google APIs, Vector Databases, OpenAI GPT-3 API, LangChain, D3.js, Plotly.js, Dashboards, Data Visualization, Full-stack, GraphQL, Back-end, Automation, Content Management Systems (CMS), JSON

Front-end Lecturer

2020 - PRESENT
  • Lectured at several 3-month-long front-end boot camps, teaching and coaching 150+ women on becoming junior React developers from scratch.
  • Prepared tens of hours of materials and exercises related to front-end technologies, mainly JavaScript and React.
  • Acted as a mentor on multiple final projects, consulting project architecture approaches, designs, clean code, and technologies used.
Technologies: React, CSS, HTML, JavaScript, Team Leadership, Software Architecture, Architecture, JSON, Functional Programming

Full-stack Web Developer

2018 - 2020
DEVIX Technologies s.r.o
  • Developed a CMS for concurrent uploading and managing video files such as movies or TV show episodes and daily saving hours of users' time.
  • Implemented and integrated a custom action tracking tool for an online store, allowing the company to collect and analyze user activity.
  • Built an extensive, component-based mailing application similar to Mailchimp for marketing messages with live preview and staging.
  • Redesigned and rewrote a price and product comparing platform utilizing SSR and custom drag-and-drop Vue components. Tens of thousands of users use the site.
  • Created a CMS for managing the company's invoices and employees using React and GraphQL.
Technologies: NPM, jQuery, Quasar, Vuex, MongoDB, Express.js, CSS, Git, Scrum, Agile, Node.js, JavaScript, SCSS, HTML5, Vue, Trello, Firebase, MUI (formerly Material UI), Single-page Applications (SPA), REST, RESTful Services, Back-end, Webpack, Confluence, JSON, Mongoose, REST APIs

Full-stack Web Developer

2016 - 2018
  • Created a custom responsive drag-and-drop tool in React—connecting calendar, note, and appointment functions and saving users from using multiple applications.
  • Implemented a car location tracking system that calculates potential banner revenue based on impressions for a React Native application.
  • Supervised and trained a team of two front-end interns.
  • Developed precise airspace tracking of drones, processing their attributes such as height, atmospheric pressure, or tilt for a web application.
  • Created a secure flight scheduling application for pilots with a custom calendar component.
Technologies: NPM, React Router, CSS, Git, React Native, MongoDB, Express.js, Node.js, jQuery, JavaScript, SCSS, HTML5, Redux, React, Front-end Development, Full-stack Development, Microservices, Shopify, Toolkits, REST, RESTful Services, Back-end, Webpack, JSON, Mongoose, REST APIs

Recipe Smarter
An AI-powered app for generating personalized recipes and meal plans to fit users' dietary needs and preferences. I was the solo developer, bringing the app from conception to launch with all the bells and whistles.

Custom Emailing CMS for an eCommerce Company

A complete content management system (CMS) that allowed for filtering, sorting, and organizing marketing messages for easy management and analysis that successfully reduced emailing costs by over 90%.

Developed a component-based marketing email application that utilized Vue and Quasar for easy customization and scalability, closely working with a team consisting of a PO, designer, two back-end developers, and QAs.

Integrated the mailing application into the company's existing system and database, ensuring seamless communication between different components of the system.

Public Facing Website for an Advertising Company

Rewrote and redesigned a project in Vue, improving the website's responsiveness and speed by over 50% and increasing mobile usage by over 100%.

Integrated and managed the website's back end using Prismic, a headless CMS, to enable easy content management and updates.

Developed custom responsive components to ensure the optimal layout and scalability of the website on different devices and screen sizes. Optimized for page speed and SEO, which resulted in improved search engine rankings and increased traffic to the website.

Integrated several third-party APIs (such as HiBob) and implemented Gmail authentication to enhance the website's functionality and user experience.

Q&A and Video Ingestion Slack Bot

Developed and deployed a custom Slack bot that utilizes Google's Dialogflow to provide users with a Q&A channel and form-based media processing capabilities.

Utilized media downloading libraries and FFmpeg to programmatically download videos and apply user-defined edits and parameters, resulting in an over 10x increase in productivity for the creative team.

Integrated with Iconik, a cloud-based content management system, to seamlessly upload processed media and eliminate the need for manual asset management.


HTML, JavaScript, HTML5, CSS, SCSS, ES8, TypeScript, GraphQL, Google Apps Script, ECMAScript (ES6), Python


Redux, Next.js, MUI (formerly Material UI), Quasar, Express.js, React Native, JSON Web Tokens (JWT), Tailwind CSS


React, Vue, Redux-Saga, React Router, Vuex, jQuery, REST APIs, Slack API, Google API, Node.js, Google APIs, Plotly.js, D3.js, ImageMagick, FFmpeg, Stripe


Slack, Trello, Dialogflow, NPM, Git, Create React App, Redux Thunk, Mongoose, Prisma, Jira, Confluence, Webpack, GitLab


REST, Scrum, Agile, Functional Programming, Automation, Microservices, Lambda Architecture, Serverless Architecture


Netlify, MacOS, Firebase, AWS Lambda, Amazon Web Services (AWS), Docker, Visual Studio Code (VS Code), Shopify


Software Development, OpenAI GPT-3 API, Architecture, Software Architecture, Full-stack Development, Front-end Development, Single-page Applications (SPA), Data Visualization, Full-stack, Back-end, RESTful Services, Gatsby, Communication, APIs, Styled-components, GPT, Generative Pre-trained Transformers (GPT), LangChain, ChatGPT, OpenAI GPT-4 API, Team Leadership, Dashboards, Serverless, Lambda Functions, Infrastructure as Code (IaC), Content Management Systems (CMS), User Experience (UX), User Interface (UI), Prismic, Slackbot, Iconic, Computer Science, Information Science, Supabase, OpenAI, Image Processing, Vector Databases, Pinecone, Artificial Intelligence (AI), Cloudflare, Toolkits


MongoDB, JSON, PostgreSQL, Backblaze B2

2016 - 2019

Bachelor's Degree in Computer and Information Science

Czech Technical University - Prague, Czech Republic