Alexey Kuznetsov, Developer in Barcelona, Spain
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Alexey Kuznetsov

Verified Expert  in Engineering

Full-stack Developer

Location
Barcelona, Spain
Toptal Member Since
March 18, 2022

Alexey has a master's degree in computer science. He worked on different projects, from large web portals and mobile apps to rail dispatching systems and custom CI/CD servers. Alexey is proactive and focused on results, product quality, and maintainability. He has excellent communication and problem-solving skills and pays attention to mentorship and expertise sharing. He prefers to work on socially important projects.

Portfolio

Tomasz Trzebiatowski Photography
React Native, Full-stack, React, TypeScript, Supabase, Mobile, Next.js
INTEDOCS SOLUCIONES DIGITALES S.L
React, JavaScript, TypeScript, Front-end, Front-end Development, Next.js...
B Lab Company - Nonprofit
Gatsby, GraphQL, React, Webpack, TypeScript, Tailwind CSS, Contentful...

Experience

Availability

Part-time

Preferred Environment

MacOS, Slack, Visual Studio Code (VS Code), GitHub

The most amazing...

...thing I've developed is a health and fitness platform called Wispence. It helps thousands of people lead a healthy lifestyle.

Work Experience

React Native Full-stack Developer

2022 - 2023
Tomasz Trzebiatowski Photography
  • Developed a social network for photographers called Frames.
  • Built the network from scratch, based on layouts in Figma, with more than 50 screens.
  • Implemented a recommendation service to deliver a personalized feed.
Technologies: React Native, Full-stack, React, TypeScript, Supabase, Mobile, Next.js

Senior Front-end Architect

2022 - 2022
INTEDOCS SOLUCIONES DIGITALES S.L
  • Designed and implemented a new version of the booking engine using best practices.
  • Accelerated the build of the static version of the site by a factor of 50 through an optimal caching strategy.
  • Provided a 100% Lighthouse score in terms of Performance, Accessibility, and Best Practices metrics.
Technologies: React, JavaScript, TypeScript, Front-end, Front-end Development, Next.js, Front-end Build Tools, Front-end Architecture, Vercel, Remix, Storybook, Unit Testing, A11Y, Accessibility, Monorepos, Babel, ESLint, Jest, PostCSS, Tailwind CSS, HTML5, CSS3, Node.js, Figma, Webpack, Playwright, Axe, SSG, Performance, Mobile Web, Full-stack, Google Tag Manager, Search Engine Optimization (SEO)

Senior Full-stack Developer

2022 - 2022
B Lab Company - Nonprofit
  • Developed a universal design system capable of working in both React and Elm environments (at the expense of Web Components) and covered by automatic visual tests and documentation.
  • Set up and transferred the project to a mono repository using Turborepo and pnpm.
  • Automated the content addition and page generation with Gatsby and Contentful.
Technologies: Gatsby, GraphQL, React, Webpack, TypeScript, Tailwind CSS, Contentful, Internationalization, Percy, Cypress, Jest, Storybook, Babel, Axe, ESLint, TypeScript 3, Prettier, Node.js, Turborepo, Monorepos, PNPM, Preact, HTML5 Custom Elements, Web Components, Next.js, SSG, A11Y, MDX, Playwright, Vite, Web Development, HTML, HTML5, User Experience (UX), User Interface (UI), Minimum Viable Product (MVP), UI Components, APIs, API Integration, Full-stack, Full-stack Development, Figma, Svelte, Vue, Front-end Development, Front-end, Software Design, Integration, Responsive Web Apps, Pixel Perfect, Databases, Relational Database Design, JSON Web Tokens (JWT), JSX, Code Review, Source Code Review, Task Analysis, JSON, Responsive UI, Vanilla JS, CSS, Accessibility, WCAG 2, CI/CD Pipelines, UX Design, Front-end Architecture, Performance, Content Management Systems (CMS), Mobile Web, Google Tag Manager

Chief Technology Officer

2020 - 2022
Wispence
  • Implemented a fully functional MVP of the project in five weeks.
  • Designed an architecture that ensures painless growth of the project to 40+ business domains and 500,000+ lines of code, not including generated code.
  • Agreed and maintained uptime SLA at the level of 99.5% throughout the project lifetime.
  • Implemented a multi-platform design system using atomic design principles, React Native for web, React Native Reanimated, Storybook, and Chromatic to speed up the development by 30% and reduce support costs.
Technologies: TypeScript, React, React Native, Node.js, PostgreSQL, GraphQL, Terraform, Docker, Vault, Redux, RxJS, Datadog, Intercom, Firebase, React Navigation, SendGrid, Sentry, Stripe, Auth0, Gatsby, i18n, AppsFlyer, Facebook SDK, IAP SDK, Nx, Domain-driven Design (DDD), Microservices, Serverless, Functional Programming, System Design, GitHub, Storybook, Jest, React Native for Web, Agile, Scrum, JavaScript, Full-stack, CSS-in-JS, CSS, SQL, Front-end Development, Back-end Development, Responsive Design, Git, APIs, Tailwind CSS, Internationalization, Contentful, Webpack, Amazon Web Services (AWS), Back-end, AWS Amplify, AWS IAM, Amazon S3 (AWS S3), Amazon RDS, A11Y, SSG, PNPM, Monorepos, Prettier, TypeScript 3, ESLint, Babel, Web Development, HTML, HTML5, Stripe API, User Experience (UX), User Interface (UI), Minimum Viable Product (MVP), UI Components, Hasura, React Apollo, Apollo, Apollo Server, Recharts, Charts, API Integration, Full-stack Development, Affiliate Programs, JavaScript Charting, React Redux, Figma, New Relic, Front-end, Axios, Architecture, Software Design, Integration, Responsive Web Apps, WebSockets, Pixel Perfect, Databases, Relational Database Design, JSON Web Tokens (JWT), OAuth, JSX, Android, iOS, CTO, Code Review, Source Code Review, Interviewing, Task Analysis, Team Management, Cloud Deployment, Scalable Application, DevOps, Cloud, Relational Databases, Google Play Store, Mobile App Development, App Store, Mobile Development, REST APIs, JSON, Responsive UI, Vanilla JS, Expo, Accessibility, WCAG 2, Software Architecture, Dashboards, Amazon EC2, Linux, Payment APIs, CI/CD Pipelines, UX Design, Product Leadership, Front-end Architecture, Performance, React Router, Content Management Systems (CMS), Video Players, HTTP Live Streaming (HLS), Shaka Player, Mobile Web, Google Tag Manager, Search Engine Optimization (SEO), Mobile

Technical Lead

2016 - 2020
GeekBrains
  • Initiated a process of extracting services from monolith to reduce cohesion.
  • Designed and developed a new learning management system supporting collaborative functions. The system's core is based on CRDT, which allows multiple content makers to collaborate easily on educational content.
  • Ensured the stability of the project development during 25x growth in four years.
  • Mentored a group of students during their internship. As a result, some of them got a job in VK, one of the country's largest IT companies.
Technologies: TypeScript, Ruby, Ruby on Rails 5, Go, Elixir, Node.js, Docker, Kubernetes, React, React Native, CQRS, Domain-driven Design (DDD), RabbitMQ, PostgreSQL, MongoDB, Microservices, GraphQL, REST, gRPC, CRDT, Devise, GrapesJS, Sidekiq, Dry-rb, ActiveAdmin, Prometheus, Grafana, Functional Programming, Object-oriented Programming (OOP), Redis, System Design, Serverless, Vault, Redux, RxJS, i18n, Gatsby, GitHub, GitLab, Storybook, Jest, RSpec, Agile, Scrum, JavaScript, Full-stack, CSS-in-JS, CSS, SQL, Front-end Development, Back-end Development, Single Sign-on (SSO), Responsive Design, REST APIs, Git, NestJS, APIs, Bootstrap, Ruby on Rails (RoR), Internationalization, Webpack, Back-end, Amazon S3 (AWS S3), A11Y, Monorepos, Prettier, TypeScript 3, ESLint, Babel, Cypress, Web Development, HTML, HTML5, SCSS, Sass, NoSQL, User Experience (UX), User Interface (UI), Minimum Viable Product (MVP), UI Components, React Apollo, Apollo, Apollo Server, API Integration, Full-stack Development, Affiliate Programs, React Redux, Material UI, Figma, New Relic, Learning Management Systems (LMS), Front-end, Axios, Architecture, Software Design, Legacy Code, Legacy Software, Integration, Responsive Web Apps, WebSockets, Pixel Perfect, Databases, NGINX, Relational Database Design, JSON Web Tokens (JWT), OAuth, JSX, Code Review, Source Code Review, Interviewing, Task Analysis, Team Management, Cloud Deployment, Scalable Application, DevOps, Cloud, E-learning, Relational Databases, Mobile App Development, Mobile Development, JSON, Responsive UI, eCommerce, Vanilla JS, Accessibility, WCAG 2, Software Architecture, Dashboards, Linux, CI/CD Pipelines, UX Design, Product Leadership, Slate.js, GitLab CI/CD, Front-end Architecture, Performance, Jira, Video Players, FFmpeg, Mobile Web, DigitalOcean, Google Tag Manager, Search Engine Optimization (SEO), Mobile

Ruby Developer

2014 - 2016
OOO ProgramPark
  • Helped develop a high-loaded dispatching management system.
  • Automated development, testing, and deployment processes.
  • Developed DSL and a set of utilities to simplify development using a custom platform.
Technologies: Ruby, JRuby, Java, Oracle, Object-oriented Programming (OOP), System Design, Ruby on Rails 5, RSpec, SQL, Back-end Development, Git, Ruby on Rails (RoR), User Experience (UX), User Interface (UI), Software Design, Legacy Code, Legacy Software, Databases, NGINX, Relational Database Design, Task Analysis, Relational Databases, REST APIs, JSON, Linux, Performance

C++ and Qt Developer

2012 - 2014
Vega (Radio Engineering Concern)
  • Implemented a graphical interface for the flight task operator.
  • Collected feedback from flight mission operators during testing.
  • Developed utilities to improve the process of collaborative work.
Technologies: C++, Qt, Ruby, Object-oriented Programming (OOP), System Design, User Experience (UX), User Interface (UI), Software Design, Databases, Relational Database Design, Task Analysis, Linux

Wispence

http://wispence.com
Wispence is a website and application for physical and mental health. I served as the chief technology officer, responsible for the project architecture and technology selection, front-end, back-end, and mobile development, leading the development and QA teams. High-quality architecture ensured the smooth operation of the service and maintained the pace of functionality development.

Universal Subscription Model for a Fitness Startup

http://wispence.com
The business needed to integrate several subscription payment services into a single system.

The project included the following functionalities:

• Bring data together from multiple payment providers, like Stripe, Apple, and Google.
• Support different types of subscriptions and one-time purchases.
• Subscribe to web and mobile apps.
• Support discount coupons and promo codes
• Automatic product updates without the re-issue of iOS and Android apps.
• Admin panel, with several capabilities:
a) Add new products, adjust pricing based on the store's country, and customize discounts.
b.) Promo code generation.
c.) Provide trials to individual users.
d.) Issue refunds.
e.) Pause subscriptions for users.

I acted as the architect and full-stack developer. My tasks included the full implementation of the project, namely:

• Collection and analysis of system requirements
• Designing data models and a database that supports working with various billing providers (Stripe, Apple, Google) and meeting system requirements
• Back-end development of client and admin APIs
• Website and mobile apps UI development
• Integration with billing providers on the front and back end
• Development of the admin panel for needed operations

Custom React Video Player for a Fitness Startup

http://wispence.com
The business's primary value is delivering quality video content with fitness training. Customizing an existing video player was necessary for easy interaction with it. The project included the following functionality:

• Save viewing progress for seamless switching between devices, syncing with smart devices, and monitoring workout progress
• The ability to select the quality of video, audio track, subtitles, music
• UI styling
• Fullscreen mode support
• Volume control, rewinding
• Keyboard control support

I worked on the project as an architect and full-stack developer. My tasks included the full implementation of the project, namely:

• Collection and analysis of system requirements
• Choice of technologies that meet the requirements (I took ReactPlayer as a basis)
• Interface implementation based on the design
• Implementation of the necessary player business logic
• Working with the internal HLS player to filter and control the audio tracks
• Additional customization for iOS and Safari
• Recording and saving viewing progress in the database

Custom React Native Video Player Component for a Fitness Startup

http://wispence.com
The business's primary value is delivering quality video content with fitness training. Customizing an existing video player was necessary for easy interaction with it. The project included the following functionality:

• Save viewing progress for seamless switching between devices, syncing with smart devices, and monitoring workout progress
• The ability to select the quality of video, audio track, subtitles, music
• UI styling
• Fullscreen mode with rotation lock
• Volume control, rewinding
• Gesture support
• Prohibition of screenshots and video recording of the screen while watching a video

I worked on the project as an architect and full-stack developer. My tasks included full implementation of the project, namely:

• Collecting and the analysis of system requirements
• Selecting technologies that meet the requirements (I took React Native Player as a basis)
• Implementing the interface based on the design
• Implementing the necessary player business logic
• Recording and saving the viewing progress in the database

Development of Fault-tolerant Infrastructure for a Fitness Project

http://wispence.com
The business needed a fault-tolerant infrastructure that provided automatic scalability and easy monitoring. The project had the following requirements:

• Ease of adding new services as the project evolved
• Automatic scaling
• High level of security and DDOS protection
• Continuous integration and deployment
• Cost minimization
• Resource monitoring and alerts

I worked on the project as an architect and DevOps engineer. My tasks included the complete implementation of the project, namely:

• Collection and analysis of system requirements
• Selection of technologies to meet the requirements (AWS, Terraform, Serverless)
• System architecture description
• Implementation of Terraform script for the automation of infrastructure deployment, monitoring settings, and alerts
• Configuration of the CI/CD front-end applications using AWS Amplify
• Traffic routing to cheaper storage for the sake of optimizing the cost of the service

Referral Program for a Fitness Startup

http://wispence.com
The business needed to develop a referral program for trainers and users. The project included the following functionality:

• When users register on the site or in the app, the referral link they come through is tracked.
• Trainers get a percentage of payments for clients who register through their referral link or landing page.
• Users get additional months of subscriptions for referrals who register through their link.
• Admin dashboard for tracking key metrics.
• Manager's dashboard, through which he makes payments to trainers.
• Trainer's dashboard for tracking the number of his referrals' registrations and payouts.
• A user dashboard for tracking the number of registrations of their referrals and bonus months of subscriptions.
• Referral information is saved when registering through the app.

I worked on the project as an architect and full-stack developer. My tasks included full implementation of the project, namely:

• requirements gathering and project architecture development
• development of the back-end and database models
• development of dashboards for different categories of users
• implementation of multiplatform links using Firebase Dynamic links, support for custom domains in the React Native application

Blog Reimplementation for a Fitness Startup

http://wispence.com
The business had a blog developed on Netlify CMS that stopped meeting requirements.
Namely:
• ease of adding new articles by content managers
• control of localization of articles into other languages
• ease of integration into a mobile app

I worked on the project as an architect and full-stack developer. My goal was the full implementation of the project, namely:
• collect requirements for a new system
• choosing an optimal technology (Contentful)
• develop data models in Contentful
• migrate relevant articles to the new system
• integration with the Gatsby website
• integration with the mobile application on React Native, cache and reloading of the blog content in the background
• implementation of Rich Text parser for React Native

Rich Text Editor for EdTech company

The business needed to implement a text editor that meets the following requirements:
• ability to work collaboratively
• document layout control
• support of history changes, undo/redo

I worked on the project as an architect and full-stack developer. My tasks included full implementation of the project, namely:
• requirements gathering and analysis
• selecting the best solution (Prosemirror, Logux)
• UI styling
• describing schemes for different types of documents
• Prosemirror configuration
• setting up a Logux server for collaborative work
• RBAC configuration
• performance optimizations

Languages

TypeScript, GraphQL, Ruby, JavaScript, CSS, TypeScript 3, HTML, HTML5, JRuby, SQL, SCSS, Sass, Go, Elixir, Java, C++, C, Assembler, MDX, CSS3, YAML

Frameworks

React Native, Redux, Ruby on Rails 5, Jest, Ruby on Rails (RoR), Next.js, JSON Web Tokens (JWT), Material UI, Vanilla JS, gRPC, GrapesJS, Qt, NestJS, Bootstrap, Tailwind CSS, Cypress, Svelte, Serverless Framework, Realtime, Remix

Libraries/APIs

React, Node.js, React Navigation, Stripe, React Native for Web, REST APIs, Stripe API, React Redux, Devise, Sidekiq, Preact, Recharts, JavaScript Charting, Shaka Player, React Router, FFmpeg, RxJS, Facebook SDK, AWS Amplify, Playwright, Vue, Stripe Connect, Stripe Connect API, Apple Subscriptions, Google Play API, Hls.js, LocalStorage, Lodash

Tools

Slack, Auth0, GitHub, RSpec, Git, JSX, Vault, Sentry, GitLab, React Apollo, Figma, Expo, GitLab CI/CD, Terraform, SendGrid, RabbitMQ, Grafana, Webpack, AWS IAM, Prisma, Babel, NGINX, Stripe Checkout, Amazon Elastic Container Service (Amazon ECS), Amazon Virtual Private Cloud (VPC), AWS Key Management Service (KMS), Amazon CloudFront CDN, AWS CloudFormation, Amazon CloudWatch, Amazon Simple Notification Service (Amazon SNS), Front-end Build Tools, PostCSS, Jira

Paradigms

Microservices, REST, Functional Programming, Object-oriented Programming (OOP), Mobile Development, CQRS, Agile, Scrum, Scalable Application, DevOps, UX Design, Lambda Architecture, Serverless Architecture, Unit Testing, Search Engine Optimization (SEO)

Platforms

MacOS, Visual Studio Code (VS Code), Docker, Mobile, Firebase, Contentful, Amazon Web Services (AWS), New Relic, Android, iOS, Amazon EC2, Linux, AppsFlyer, Kubernetes, Oracle, Safari, AWS Lambda, AWS ALB, Netlify, Vercel, DigitalOcean

Storage

Hasura, Databases, JSON, PostgreSQL, Amazon S3 (AWS S3), NoSQL, Cloud Deployment, Relational Databases, Datadog, MongoDB, Redis

Industry Expertise

E-learning

Other

Gatsby, i18n, Nx, Domain-driven Design (DDD), Dry-rb, ActiveAdmin, Serverless, System Design, Storybook, CSS-in-JS, Full-stack, Front-end Development, Back-end Development, APIs, Internationalization, Back-end, Prettier, Monorepos, Web Development, User Experience (UX), Minimum Viable Product (MVP), UI Components, API Integration, Full-stack Development, Learning Management Systems (LMS), Front-end, Axios, Architecture, Software Design, Legacy Code, Legacy Software, Integration, Responsive Web Apps, Pixel Perfect, Relational Database Design, Code Review, Source Code Review, Task Analysis, Team Management, Mobile App Development, Responsive UI, Software Architecture, Dashboards, Front-end Architecture, Mobile Web, CRDT, Responsive Design, ESLint, Turborepo, PNPM, HTML5 Custom Elements, Web Components, A11Y, User Interface (UI), Apollo, Apollo Server, Charts, Affiliate Programs, WebSockets, OAuth, CTO, HTTP Live Streaming (HLS), CI/CD Pipelines, Cloud, Google Play Store, App Store, eCommerce, Accessibility, WCAG 2, Payment APIs, Product Leadership, Slate.js, Performance, Content Management Systems (CMS), Video Players, Supabase, Intercom, IAP SDK, Prometheus, Single Sign-on (SSO), Amazon RDS, Percy, Axe, SSG, Vite, Interviewing, Stripe Subscriptions, Stripe Payments, Webhooks, Subscriptions, In-app Purchases, Google In-app Billing, React Player, Video Streaming, Dynamic Adaptive Streaming over HTTP (DASH), Amazon Route 53, API Gateways, ECS, Identity & Access Management (IAM), Lambda Functions, Relational Database Services (RDS), Firebase Dynamic Links, ProseMirror, Logux, Applications, Videos, Google Tag Manager

2006 - 2012

Master's Degree in Computer Science

Moscow Institute of Radio Engineering, Electronics and Automation (MIREA) - Moscow, Russia

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