Andrey Korin, Developer in Alicante, Spain
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Andrey Korin

Verified Expert  in Engineering

Software Developer

Alicante, Spain

Toptal member since February 8, 2018

Expertise
Full-stackPythonJSONJavaScriptCSSReact.jsNode.jsExpress.jsTailwind CSSData VisualizationOpenAISQLMySQLAuth0WebRTC
Bio

Andrey is a highly skilled and disciplined lead full-stack developer with extensive experience building complex web applications using a diverse range of front-end and back-end technologies. He is an expert in JavaScript development and has successfully collaborated with remote, distributed teams. He's built and led a team of engineers who successfully launched enterprise-grade products into production. With a strong eye for design, Andrey has also won several application design contests.

Portfolio

23 Software
JavaScript, TypeScript, SQL, Technical Hiring, Team Leadership, Figma, CSS...
Systems Insight Inc.
JavaScript, React, MySQL, SQL Server 2010, React Native, iOS SDK, Stripe...
Sweetbridge
Ethereum, Auth0, GraphQL, React, PostgreSQL, Node.js, TypeScript, JavaScript...

Experience

  • SQL - 18 years
  • Python - 18 years
  • JavaScript - 15 years
  • Linux - 10 years
  • TypeScript - 10 years
  • Node.js - 9 years
  • React - 9 years
  • MongoDB - 4 years

Availability

Full-time

Preferred Environment

Linux, Docker, Git, MacOS

The most amazing...

...thing I've solo-launched is my side-project called Ultimaps, where I handled design, development, DevOps, and even sales and marketing.

Work Experience

Lead Full-stack Developer

2021 - PRESENT
23 Software
  • Founded and led a full-stack engineering team that designs, builds, and ships custom web applications for clients across industries.
  • Built and scaled a remote engineering team from the ground up.
  • Worked as a hands-on architect and contributor, balancing leadership with coding critical features and system design (still actively review and merge PRs and troubleshoot production issues).
Technologies: JavaScript, TypeScript, SQL, Technical Hiring, Team Leadership, Figma, CSS, HTML, JSON, Payment APIs, Technical Leadership, Software Architecture, Full-stack Development, Full-stack, Express.js, Docker, APIs

Senior Full-stack Developer

2018 - 2021
Systems Insight Inc.
  • Developed a feature-rich web application for stylists to manage their appointments.
  • Created a web application allowing retailers to search for available properties and for property owners to search for retailers using the matching algorithm based on input characteristics.
  • Built a web application for the large US laboratory allowing them to accept orders from their clients on their website.
Technologies: JavaScript, React, MySQL, SQL Server 2010, React Native, iOS SDK, Stripe, Stripe Payments, SQL, Amazon Web Services (AWS), CSS, HTML, JSON, Payment APIs, Software Architecture, Full-stack Development, Full-stack, Express.js, Docker, APIs

Senior Full-stack Developer

2018 - 2019
Sweetbridge
  • Developed a complex UI application powered by React and Redux.
  • Built a wallet for an Ethereum (ETH) network that supported ETH and ERC20 tokens, allowing users to transfer their funds and monitor their balances.
  • Integrated Ledger hardware wallet support, allowing users to sign transactions.
  • Developed a GraphQL back-end powered by Node.js, supporting Auth0 authorization and roles and permissions.
Technologies: Ethereum, Auth0, GraphQL, React, PostgreSQL, Node.js, TypeScript, JavaScript, Web3.js, Solidity, CSS, HTML, JSON, Full-stack Development, Crypto, Full-stack, APIs

Senior Full-stack Engineer

2016 - 2018
Jobdone
  • Created an entire web application using Python with the Flask framework on the back-end and a Vue.js application bundled with Webpack on the front-end.
  • Built an automatic system to accept BTC payments based on BIP-32 (addresses can be generated on the server without the need to keep private keys on the server).
  • Developed a real-time messaging system using Node.js and SockJS.
  • Learned a lot about Elasticsearch while building the search feature.
Technologies: SockJS, Bitcoin, Elasticsearch, Vue, Node.js, MySQL, Flask, Python, Vue 2, SQL, CSS, HTML, JSON, Payment APIs, Software Architecture, Full-stack Development, Crypto, Full-stack, Stripe Payments, Stripe, APIs

Full-stack Engineer

2016 - 2017
MMDSmart
  • Created an SMS gateway system from scratch which now handles at least 50,000 messages per day. The system contains a public API developed using Node.js, a UI web application developed with React and Redux, and a couple of back-end utilities talking to soft-switches.
  • Built a beautiful web app with React and Redux for a legacy system written in C++; MySQL was used to interact between the parties and the application was backed by Node.js.
  • Learned a lot about the telecom-related field.
  • Implemented Redux in every project while working here.
Technologies: Webpack, Redux, React, MySQL, TypeScript, Node.js, SQL, Amazon Web Services (AWS), CSS, HTML, JSON, Payment APIs, Software Architecture, Full-stack Development, Full-stack, Express.js, APIs

Full-stack Engineer

2015 - 2016
testRTC
  • Hacked browser APIs to support fake media streams for WebRTC calls in an automated environment.
  • Wrote a huge amount of custom extensions for Nightwatch.js and a Node.js automation framework on top of Selenium.
  • Developed and supported browser extensions for Chrome and Firefox.
  • Worked on a large amount of data processing of WebRTC statistics (we used TypeScript on the back-end for that purpose).
  • Continuously patched Docker images to make WebRTC calls working on Firefox and Chrome running inside a Docker environment.
Technologies: Browsers, Extensions, AngularJS, Selenium, Docker, WebRTC, TypeScript, Node.js, Chrome Extensions, CSS, HTML, JSON, Full-stack Development, Full-stack, Firefox Extensions, APIs

Front-end Engineer

2013 - 2015
Lintelus
  • Gained valuable experience working with the top (at the time) HTML5/CSS3 browser features, such as canvas, media elements, and more.
  • Fixed a huge number of cross-browser issues with CSS3 and SVG displays (we supported IE as well).
  • Created our own JavaScript-and-SVG framework for animations, reiterating most of PowerPoint animations (we translated PPTX slides into HTML5).
  • Built our own JavaScript-and-SVG framework to render nearly all of the PowerPoint charts.
  • Learned Node.js and evolved from pure front-end development to full-stack development.
Technologies: SVG, CSS3, Backbone.js, Node.js, JavaScript, CSS, HTML, JSON, APIs

Java Engineer

2011 - 2012
Amazon Robotics
  • Supported the UI back-end, implemented it as a state machine while working in a distributed team of more than 100 engineers on a huge codebase (mostly written in Java 5).
  • Created a test framework to write automated tests for the UI state machine.
  • Debugged complex memory-leak bugs with heap profilers while in a multithread environment.
Technologies: Linux, MySQL, Java

Python Developer

2007 - 2011
Insitute of Education Development Nizhny Novgorod
  • Developed a lot of data-processing utilities using Python. Mostly it was table data processing from XLS/CSV files with various data schemas.
  • Created a network equipment management system with Python and Django.
  • Built a helpdesk system to track users issues with Python, Django, and Java Client for installation on users machines for faster communication and problem resolution.
  • Automated the installation of software on new machines with a hand-written tool using C.
Technologies: Django, Linux, Bash, Python, SQL, HTML

Experience

Ultimaps | Create Maps with Data Online

http://ultimaps.com
This web application is one of my side projects, where my passions for cartography and programming intersect. I am responsible for every part of the project, including the design and infrastructure.

A Freelance Services Marketplace

https://jobdone.net
This is a marketplace that connects freelance workers with potential clients. It was a complex project developed completely and solely by me (except for some HTML/CSS). On the back end, I used Python with the Flask framework, MySQL for storage, Elasticsearch as a search engine, Node.js for a real-time messaging system, and Vue.js and Webpack on the front end.

NPM Package to Upload/Download Azure Blobs

https://www.npmjs.com/package/azureblob-upload-node
A package for Node.js which provides some nice features to deal with Azure blobs which are not available in the official Azure SDK package, such as support for blobs, streams, gzip compression, and retry support.

Education

2005 - 2009

Bachelor's Degree in Computer Science

Nizhny Novgorod State Technical University - Nizhny Novgorod, Russia

Skills

Libraries/APIs

Nightwatch.js, React, Node.js, WebRTC, Vue, Vue 2, Stripe, Backbone.js, SockJS, D3.js, Web3.js

Tools

Webpack, Figma, Sublime Text 3, Git, Auth0, n8n, GIS

Languages

JavaScript, Python, CSS, HTML, SQL, TypeScript, CSS3, Java, GraphQL, Bash, Solidity

Frameworks

Express.js, Tailwind CSS, Redux, Flask, Next.js, AngularJS, Selenium, Django, React Native, iOS SDK

Storage

JSON, MySQL, Amazon S3 (AWS S3), MongoDB, Elasticsearch, PostgreSQL, SQL Server 2010

Platforms

Docker, Linux, MacOS, Ethereum, Amazon Web Services (AWS)

Paradigms

UI Design

Other

SVG, Full-stack, Full-stack Development, APIs, Stripe Payments, OpenAI, Data Visualization, Payment APIs, Software Architecture, FastAPI, Extensions, Browsers, Chrome Extensions, Firefox Extensions, Bitcoin, Technical Hiring, Team Leadership, Crypto, Technical Leadership, Artificial Intelligence (AI)

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