Hi, I'm Sergei πŸ‘‹
Middle Frontend Developer
SS

About

Middle Frontend Developer with backend knowledge (6+ years full-time) and a deep understanding of developing complex projects in e-commerce product startups. I've developed about 20 commercial projects from idea to release, used by hundreds of thousands of people, and refactored many projects from outdated to modern technologies. Proficient in JavaScript, TypeScript, React, Redux, CSS, and other technologies. I can write e2e (Cypress) and unit tests (Jest). I have experience with backend technologies: Node.js, Express, MongoDB. I love learning and can quickly pick up any technology you need.

Video resume

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Work Experience

M

My Gift Card

September 2023 - Present
Middle Frontend Developer
● Developed and maintained Vue, React, JS, TS tasks of any complexity, refactoring, supporting the frontend of all company and partner projects: online stores, widgets, showcases, admin panels, gift certificates.
● Developed three large admin panels from scratch in a short time, allowing clients to manage their products and personal accounts themselves, previously done through managers and programmers, saving hundreds of employee hours.
● Developed a new UI kit, which allowed updating the company's design, making products visually appealing.
● Wrote autotests for existing projects with cypress.js, which helped find and fix bugs, increasing project stability.
● Developed a fullstack frontend logging service (React.js frontend, Node.js backend, MongoDB). Implemented log collection and sending in all frontend projects, allowing early detection and correction of frontend errors.
● Integrated Artificial Intelligence into company products, created fullstack JavaScript applications for generating AI images and congratulatory texts for gift certificates, which differentiated the product in the market and increased functionality and sales.
● Made an AI bot that responds to user messages, this reduced the load on the support center and greatly reduced costs.
● Developed a training platform for Alfa-Bank employees on demand from Alfa-Bank, and an online store with a referral program on demand from Belis.
D

Digift Gift Cards

February 2020 - August 2023
Middle Frontend Developer
● Developed about 15 complex SPA projects from scratch (admin panel, online store, widgets, payment system, B2B/B2C platforms, iframe projects embedded into partner websites) from idea to release, using Scrum. These projects are used by tens of thousands of people and generate main revenue.
● Reworked 5 large old projects from outdated technologies (PHP 5, Vue 1, jQuery) to new ones (TypeScript, React, Redux), reducing feature implementation time and saving thousands of development hours.
● Supported all projects, including legacy code, fixed bugs, implemented features, improved existing projects, regularly reviewed and refactored code, which increased sales and improved reputation.
● Took full responsibility for most projects, participated in architectural design. Many fundamental decisions were made by me, such as the choice of technologies, programming language, architecture, allowing the use of the latest technologies and best development practices.
● Onboarded middle-level employees, recruited team members, conducted technical interviews, made training videos for my team and for company clients. This allowed new employees to quickly join the team and contribute.
● Conducted SEO optimization of our React projects (NextJS, PHP), allowing them to appear more frequently in search results and attract more clients.
● Developed many different and complex email templates, implemented WebSocket in project code, token-based authorization, developed two UI kits, added new complex and modern animations for all projects, implemented third-party integration with partner projects.
● Implemented user interaction-improving features in projects: email autofill, phone input mask with country flags, image cropping, multiple form validation, error and hint display, automatic data replacement, project localization.
● My projects had 85% test coverage (unit testing Jest, e2e testing Cypress), which reduced the number of bugs due to their quick detection, making the project stable.
● Adapted projects for different browsers (Safari, Firefox, Chromium), different operating systems (macOS, Linux, Windows), and different devices. Solved problems arising in each specific browser and operating system.
F

Foodle

February 2019 - January 2020
Frontend Developer
● Developed a project (React) that displays restaurants on maps, restaurant menus, and allows ordering from restaurants (the main business idea).
● As part of the team, I participated in the architectural development of the future project. I proposed ideas that were implemented and reduced server load, increasing project performance.
● Fixed bugs on the main website, implemented many features, which improved reputation and increased the number of clients; I developed websites for our partner restaurants.
● My projects had 50% test coverage (Jest), which reduced the number of bugs due to their quick detection, making the project stable.
● Conducted SEO optimization of our projects, allowing them to appear more frequently in search results and attract more clients.
● Implemented user interaction-improving features in projects: email autofill, phone input mask, validation of all data, display of errors and hints, integration of restaurants with Google Maps.
F

Freelance

May 2018 - January 2019
Frontend Developer
● Developed many websites for my clients, allowing them to have an online presence, sell services, increase revenue and sales, and improve reputation.
● Supported my clients' websites, fixed errors and bugs, added new features, and also supported CMS platforms: WordPress, Wix, Joomla. This increased sales and improved user perception of the product.

Skills

JavaScript
TypeScript
React
Redux
NextJS
Vue3
Vuex
CSS3
HTML5
Sass
Jest
Cypress
Node.js
Express
MongoDB
Webpack
Vite
Gulp
Docker
REST API
WebSocket
MaterialUI
Vuetify
jQuery
Bootstrap
BEM
Git
OpenAI
Linux
Wordpress
Joomla
Wix
Figma
Zeplin
SEO
UI/UX
My Projects

MGC Projects built from scratch by me

Referral belis

Referral belis

Online store with a referral system for Belis.

JavaScript
Vue.js
Alfa bank education

Alfa bank education

Educational platform for Alfa Bank.

JavaScript
Vue.js
AI text

AI text

AI text generation for gift certificates.

TypeScript
Next.js
AI image

AI image

AI image generation for gift certificates.

TypeScript
Next.js
Vendors admin

Vendors admin

Administrative panel for My Gift Card vendors.

TypeScript
React.js
Charts admin

Charts admin

Administrative panel for My Gift Card reports.

TypeScript
React.js
ai-bot

ai-bot

AI-powered chatbot assistant.

TypeScript
React.js
Node.js
OpenAI

MGC Projects I worked on

Managers admin

Managers admin

Administrative panel for My Gift Card managers on 125 pages.

TypeScript
React.js
Widget shop

Widget shop

B2C widget for purchasing gift cards (iframe and mobile versions).

TypeScript
Next.js
Widget landing

Widget landing

B2C widget for purchasing gift cards (landing version).

TypeScript
Next.js
Certificate show

Certificate show

Display of a gift certificate.

TypeScript
Next.js
Client Admin Panel

Client Admin Panel

Custom admin panel.

TypeScript
Vue.js
MGC Promo Shop

MGC Promo Shop

Online store for exchanging points for gift cards.

JavaScript
Vue.js

Digift Projects built from scratch by me

Digift B2B widget (iframe)

Digift B2B widget (iframe)

B2B widget for corporate orders (iframe).

TypeScript
React.js
Digift B2C widget (iframe)

Digift B2C widget (iframe)

B2C widget for purchasing gift cards (iframe).

JavaScript
React.js
Digift B2C widget (desktop)

Digift B2C widget (desktop)

Desktop version of the B2C widget without iframe.

JavaScript
React.js
Digift B2C widget (mobile)

Digift B2C widget (mobile)

Mobile version of the B2C widget without iframe.

JavaScript
React.js
Gift Certificate

Gift Certificate

Gift envelope with beautiful animation.

JavaScript
React.js
Digift Tracking App

Digift Tracking App

Application for tracking gift card status.

JavaScript
React.js
Digift B2B Platform

Digift B2B Platform

Platform for corporate partners.

JavaScript
React.js
Group Purchase App

Group Purchase App

Application for group purchase of gift cards.

JavaScript
React.js
Group Purchase Tracking

Group Purchase Tracking

Application for tracking group purchase status.

JavaScript
React.js
Email Templates

Email Templates

Layout of many complex email templates using HTML/CSS.

HTML
CSS
Payment System

Payment System

Payment system (REST API and WebSocket) for card input and fast payments.

JavaScript
WebSocket
UI-kit

UI-kit

UI-kit for Digift.

JavaScript
React.js
Conference Gift App

Conference Gift App

Application where any conference participant can choose and receive a gift card.

JavaScript
React.js
Card Balance Checker

Card Balance Checker

Application for checking the balance of each card.

JavaScript
React.js

Digift Projects I worked on

Digift e-shop

Digift e-shop

Online gift card store using Vue.js.

JavaScript
Vue.js
Digift Partner Admin Panel

Digift Partner Admin Panel

Admin panel for Digift partners.

JavaScript
React.js
Digift.me exchange shop

Digift.me exchange shop

Gift card exchange.

JavaScript
jQuery
Dynamic instructions

Dynamic instructions

Dynamic instructions on how to install a widget for each partner.

JavaScript
React.js

Pet Projects

react-mmorpg-game

react-mmorpg-game

Large online MMORPG with React.js and Node.js using MongoDB: plot, leveling, 12 locations, 20 quests, battles, animations, chat, ratings, and localization for 21 languages.

TypeScript
React.js
Node.js
MongoDB
javascript-study

javascript-study

21 languages, PWA, 50 pages, 300 programming questions.

TypeScript
Next.js
blog

blog

Blog, 21 languages ​​and several blog topics.

TypeScript
Next.js
kit-classical

kit-classical

UI kit for React.js in a black and white style, with many elements.

TypeScript
React.js
users-list-react

users-list-react

React.js user list with Jest tests.

TypeScript
React.js
Jest
ai-pictures-generator

ai-pictures-generator

AI image generation with a React.js frontend and Node.js backend.

TypeScript
React.js
Node.js
AI
ai-text-generator

ai-text-generator

AI text generation with a React.js frontend and Node.js backend.

TypeScript
React.js
Node.js
AI
open-ai-pictures-generation

open-ai-pictures-generation

Requests for AI image generation from openai.com using React.js.

TypeScript
React.js
OpenAI
logging-service

logging-service

Logging service that saves and displays logs, with a React.js frontend, Node.js backend, and MongoDB.

TypeScript
React.js
Node.js
MongoDB