Sergei is available for hire
Hire SergeiSergei Kartin
Verified Expert in Engineering
Web Developer
Budva, Budva Municipality, Montenegro
Toptal member since May 9, 2017
Bio
With over 12 years of expertise in Java back-end and JavaScript front-end development, Sergei is the go-to full-stack developer for your projects. Beyond his technical prowess, his personable nature and excellent communication skills ensure seamless collaboration. Punctuality is his hallmark, guaranteeing the timely delivery of top-notch solutions. Dive deeper into Sergei's profile to unlock the potential for your next big venture.
Portfolio
Bettermode
React, GraphQL, TypeScript, Next.js, Vite, Tailwind CSS, JavaScript...
Picket Pty
GraphQL, TypeScript, React, JavaScript, CSS, Front-end Development...
ListingLoop
Jest, Redux-Saga, Redux, TypeScript, React, Firebase, JavaScript...
Experience
- CSS - 14 years
- JavaScript - 14 years
- Front-end - 14 years
- React - 7 years
- TypeScript - 7 years
- Node.js - 5 years
- Tailwind CSS - 5 years
- GraphQL - 5 years
Availability
Part-time
Preferred Environment
TypeScript, React, GraphQL
The most amazing...
...project I've worked on is Bettermode, a customizable community platform that allows users to build unique customer communities.
Work Experience
Front-end Engineer
2020 - 2024
Bettermode
- Developed a portal to manage users' communities and apps.
- Developed and maintained a UI kit using React and Tailwind, streamlining front-end development for a team of five to ten developers.
- Established a design system with theming and dark mode support, improving UI consistency and customizability.
- Improved front-end developer experience by migrating from Webpack and React 16 to Vite and React 18, reducing HMR performance from over 30 seconds to instant module replacements and cutting initial bundle size by 50%.
Technologies: React, GraphQL, TypeScript, Next.js, Vite, Tailwind CSS, JavaScript, Web Development, CSS, Front-end, Node.js, Amazon Web Services (AWS), React Query, Progressive Web Applications (PWAs), TypeORM, CI/CD Pipelines, HTML, Front-end Development, Docker, Test-driven Development (TDD), React Router, Full-stack Development, Storybook, Single-page Applications (SPAs), Server-side Rendering (SSR), Jest, Webpack, Figma, React Testing Library, Design Systems
Software Engineer (via Toptal)
2019 - 2020
Picket Pty
- Created a Facebook Messenger chatbot for prospective students at the University of Sydney, leveraging Botkit to streamline communication and improve user engagement.
- Automated responses to common student inquiries, significantly enhancing engagement and providing a more efficient and interactive user experience for prospective students.
- Utilized Botkit to develop a chatbot that effectively addressed frequently asked questions, reducing response times and increasing accessibility for prospective students seeking information.
Technologies: GraphQL, TypeScript, React, JavaScript, CSS, Front-end Development, Full-stack Development, Single-page Applications (SPAs), Webpack, React Testing Library
Front-end Engineer (via Toptal)
2018 - 2019
ListingLoop
- Developed an MVP product tailored to the Australian real estate market, utilizing technologies like Firebase, React, and Redux to deliver a robust and scalable solution.
- Architected key features and functionality that significantly enhanced the product's appeal, contributing to its successful achievement of a $500,000 crowdfunding target within three months.
- Built a component library based on atomic design principles.
Technologies: Jest, Redux-Saga, Redux, TypeScript, React, Firebase, JavaScript, Web Development, CSS, Front-end, REST APIs, HTML, Front-end Development, Test-driven Development (TDD), React Router, Full-stack Development, Single-page Applications (SPAs), Webpack, React Testing Library
Senior Java Developer
2017 - 2018
Azoft
- Led a team of five engineers to develop an MVP for a financial social network integrated with online banking.
- Refactored the Customer Loyalty Program web app for a top-five Russian bank, enhancing its scalability and enabling deployment in two additional banks.
- Integrated a Telegram bot and bank call center using Java and Spring Boot technologies.
Technologies: PostgreSQL, Spring Data, Spring Boot, Kotlin, Java, Web Development, Front-end, HTML, Test-driven Development (TDD), Full-stack Development
Senior Java Developer | Tech Lead
2010 - 2016
EasySport
- Led the development, automated testing, and deployment of a web application for booking sports courts.
- Updated an application from Java EE 5 to Java EE 7 and migrated from RichFaces to PrimeFaces.
- Refactored the core functionality to have more understandable code and better performance.
- Introduced a code-quality pipeline, including unit and Selenium tests, Jenkins CI server, and static code analysis.
Technologies: React, JPA, Enterprise Java Beans (EJB), JavaScript, Web Development, CSS, Front-end, Full-stack, HTML, Front-end Development, Full-stack Development
Software Developer
2007 - 2012
Freelance Work
- Created a WAP site for social mobile communication service.
- Developed the iPad application called Muscle & Bone Study.
- Built a website covering regional news based on Drupal.
- Crafted the UI for the Spyder display calibration software for professional photographers and studios.
- Developed a J2ME application for tourists reading RFID tags with city information.
- Created a dance studio attendance tracking application.
Technologies: Spring, JavaScript, Web Development, CSS, Front-end, Front-end Development
Java Developer
2008 - 2010
Softage
- Developed new features for a Java EE customer engagement improvement solution.
- Architected comprehensive unit tests and resolved bugs.
- Built a standalone tool for populating the database used for performance tests.
Technologies: Hibernate, Enterprise Java Beans (EJB), Java
Experience
Bettermode | Front-end Engineer
http://www.bettermode.com/Bettermode is a customizable community platform that enables users to build unique customer communities.
In addition to delivering product and consumer-facing features of the platform, I also developed and maintained a UI kit using React and Tailwind, streamlining front-end development for a team of five to ten developers. Furthermore, I established a design system with theming and dark mode support, improving UI consistency and customizability. Finally, I improved the front-end developer experience by migrating from Webpack and React 16 to Vite and React 18, reducing HMR performance from over 30 seconds to instant module replacements and cutting initial bundle size by 50%.
In addition to delivering product and consumer-facing features of the platform, I also developed and maintained a UI kit using React and Tailwind, streamlining front-end development for a team of five to ten developers. Furthermore, I established a design system with theming and dark mode support, improving UI consistency and customizability. Finally, I improved the front-end developer experience by migrating from Webpack and React 16 to Vite and React 18, reducing HMR performance from over 30 seconds to instant module replacements and cutting initial bundle size by 50%.
ListingLoop | Front-end Engineer
https://listingloop.com.au/about/ListingLoop is a real estate technology company that supports agents' work by providing a modern approach to buying and selling a property.
I developed an MVP product for the Australian real estate market using Firebase, React, and Redux. Within three months, I successfully achieved a $500,000 crowdfunding target.
I developed an MVP product for the Australian real estate market using Firebase, React, and Redux. Within three months, I successfully achieved a $500,000 crowdfunding target.
Azoft | Senior Java Developer
Led a team of five engineers to develop an MVP for a financial social network integrated with online banking.
I refactored the Customer Loyalty Program web app for a top-five Russian bank, enhancing scalability and enabling deployment in two additional banks. The technologies I used included Java, Kotlin, Spring Boot, Spring Data, and PostgreSQL.
I refactored the Customer Loyalty Program web app for a top-five Russian bank, enhancing scalability and enabling deployment in two additional banks. The technologies I used included Java, Kotlin, Spring Boot, Spring Data, and PostgreSQL.
Education
2003 - 2007
Bachelor's Degree in Information Technology
Novosibirsk State University (NSU) - Novosibirsk, Russia
Skills
Libraries/APIs
Node.js, React, React Testing Library, REST APIs, React Query, React Router, Redux-Saga
Tools
Git, Astro, Webpack, Figma
Languages
GraphQL, JavaScript, CSS, Java, TypeScript, HTML, Kotlin
Frameworks
Redux, Tailwind CSS, Next.js, Jest, Spring, Spring Boot, JPA, Hibernate
Paradigms
REST, Test-driven Development (TDD)
Storage
PostgreSQL, Spring Data
Platforms
Netlify, Firebase, Amazon Web Services (AWS), Docker
Other
Web Development, Full-stack, Front-end, Vite, Front-end Development, Single-page Applications (SPAs), Server-side Rendering (SSR), Full-stack Development, Storybook, Design Systems, Enterprise Java Beans (EJB), Progressive Web Applications (PWAs), TypeORM, CI/CD Pipelines
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