Jaroslav Vorobey, Developer in London, United Kingdom
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Jaroslav Vorobey

Verified Expert  in Engineering

React Developer

Location
London, United Kingdom
Toptal Member Since
February 17, 2022

Jaro is a startup founder who has previously worked at JPMorgan Chase & Co. and Deutsche Bank AG, with more than four years of experience ideating and overseeing the delivery of exceptional software. He excels in React, TypeScript, Next.js, Node.js, Firebase, and Google Cloud. A fast and thorough learner of new technologies and a native English and Italian speaker, Jaro enjoys working on challenging products and delivering outstanding results.

Portfolio

RealGreatDevs
JavaScript, TypeScript, CSS, Next.js, Tailwind CSS, React, React DnD...
3Cells
JavaScript, TypeScript, React, Node.js, Firebase, PostgreSQL, Google Cloud...
Hawaii Life
React, Next.js, Redux, Progressive Web Applications (PWA), Figma, REST APIs...

Experience

Availability

Part-time

Preferred Environment

Firebase, MongoDB, Node.js, React, JavaScript, TypeScript, GitHub, Bitbucket, Slack

The most amazing...

...project I've created is Winfluencer.io, a web app for YouTubers I built from scratch using React, Node.js, Material UI, Firebase, and the YouTube API.

Work Experience

Founder

2024 - PRESENT
RealGreatDevs
  • Created the world's largest database of open source developers, currently with over seven million developers and more than one million developers with email.
  • Wrote custom scrapers to gather this information quickly and cost-effectively. Currently, it is scraping at a rate of 150,000 new developers per day. Avoided bot detection using new evasive techniques.
  • Created 50,000 unique SEO results pages programmatically, which are ranking on Google.
  • Managed multiple developers to ship products quickly and without bugs via effective CI/CD automated deployments.
  • Designed and built the UI using Next.js (App Router), React Tailwind CSS TypeScript, NextAuth, Prisma, and PostgreSQL.
  • Created and optimized multiple scheduled cloud functions on Google Cloud to run in parallel, retrieving thousands of data points per second.
Technologies: JavaScript, TypeScript, CSS, Next.js, Tailwind CSS, React, React DnD, NextAuth.js, Playwright, Puppeteer, Scraping, Web Scraping, Seos, Stripe, Stripe API, Vercel, Vercel Analytics, Data Scraping, Sitemaps, Programmatic SEO, Google Search Console, Google Analytics, Google Analytics 4, PostgreSQL, Prisma, MySQL, Google Cloud Platform (GCP), Google BigQuery, Google Cloud Functions, Data Extraction, Solution Architecture, Requirements Analysis, ETL, Data Modeling, Agile Sprints, Mentorship, Off-page SEO, On-page SEO, Technical SEO, Website Audits, Axios

Founder

2020 - PRESENT
3Cells
  • Created a web scraper in Puppeteer and Node.js that gets thousands of emails weekly and automatically sends personalized emails.
  • Headed the company's sales, marketing, finance, and strategic direction.
  • Created a production application from scratch using React, Material-UI, Firebase, Google Cloud, and YouTube API.
  • Managed multiple team members to achieve weekly objectives.
Technologies: JavaScript, TypeScript, React, Node.js, Firebase, PostgreSQL, Google Cloud, Strategy, MVP Design, Consulting, Cloud Firestore, Firebase Cloud Functions, DevOps, Infrastructure, CSS, Framer, UI Animation, Animation, Front-end, Back-end, User Interface (UI), User Experience (UX), Web Scraping, Full-stack, Technical Leadership, GraphQL, Authentication, OAuth, OAuth 2, Autoscaling, Continuous Integration (CI), Microservices, AWS Lambda, Chart.js, Leadership, Shopify API, Svelte, Git, Machine Learning, Artificial Intelligence (AI), Vectors, Web Development, CSS3 Animation, Single-page Applications (SPA), Trello, Software Architecture, Full-stack Development, Front-end Development, Shopify, Remote Team Leadership, Figma, Generative Pre-trained Transformers (GPT), OpenAI GPT-4 API, HubSpot CRM, DNS, Design, Front-end Architecture, Mobile, Data Scraping, OpenAI GPT-3 API, Toolkits, REST APIs, Design Patterns, D3.js, Data Visualization, Data Processing, Data Science, Mobile Development, Microsoft Teams, Slack App, eCommerce, Scraping, Software Design, Scalability, Performance, Cloud, Integration, Social Media APIs, Social Media, Docker, Slackbot, Serverless Architecture, MERN Stack, Amazon DynamoDB, CSS3, Webpack, JSON, Babel, Responsive Web Design (RWD), SaaS, CI/CD Pipelines, JSON Web Tokens (JWT), Azure, Responsive Design, Unit Testing, Cross-browser Compatibility, ChatGPT, Vercel, Elasticsearch, Supabase, Progressive Web Applications (PWA), SQL, UI Components, Design Systems, C#, Marketing, Deployment, Mobile First, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, QR Codes, Heroku, Context API, Databases, Event-driven Architecture, Lambda Architecture, Software Engineering, Software Documentation, Technical Architecture, Business Analysis, Dashboards, Gmail API, OpenAI, Google Cloud Platform (GCP), Google BigQuery, Google Cloud Functions, Data Extraction, Solution Architecture, Requirements Analysis, ETL, Data Modeling, Agile Sprints, Mentorship, On-page SEO, Website Audits, Axios

Lead Software Engineer

2023 - 2023
Hawaii Life
  • Developed a complex Next.js progressive web app CRM with custom authentication, full Salesforce integration, Google Maps embeds, and dozens of custom responsive screens built with React and Tailwind CSS.
  • Created a custom ORM to map fields from the web app to Salesforce, using Salesforce as the single source of truth.
  • Presented the product to key stakeholders, such as the firm's head of technology, and received a very positive response.
Technologies: React, Next.js, Redux, Progressive Web Applications (PWA), Figma, REST APIs, Vercel, Tailwind CSS, NextAuth.js, CSS, Responsive, Responsive UI, PWA, Salesforce, Salesforce API, Requirements Analysis, Data Modeling, Agile Sprints, Technical SEO, Website Audits, Axios

Lead Software Engineer

2022 - 2022
Reach Digital
  • Created analytics platform in React, TypeScript, Node.js, Next.js, and MongoDB.
  • Deployed 10+ Next.js projects to Vercel for multiple eCommerce clients integrating with Shopify and Stripe API.
  • Defined the startup's product strategy with the CEO, outlining goals and deliverables. Outlined the MVP and what it should achieve. Evaluated what features to keep and cut based on relative added value to customers.
  • Designed the client- and server-side architecture, considering strict real-time responsiveness and scalability requirements, which led to its deployment to the cloud.
  • Oversaw the product launch, helping onboard initial customers while using their feedback to create additional value for the product. Consulted the CEO on the product's scalability and potential long-term solutions to strategic challenges.
  • Created DevOps CI/CD pipeline and managed deployments to Google App Engine and Cloud Functions.
  • Reverse-engineered Meta Pixel and created a pixel competitor from scratch in JavaScript, which is currently used by tens of eCommerce clients.
Technologies: React, Next.js, Node.js, Material UI, Tailwind CSS, Architecture, Mobile, Web, Milestones, Roadmaps, CTO, Startups, Cloud Infrastructure, System Architecture Design, Server Architecture, Server Infrastructure, Monday.com, APIs, Front-end, CSS, Server-side Rendering (SSR), Google Cloud Platform (GCP), Jest, Full-stack, Technical Leadership, Leadership, Shopify API, Headless Commerce, NoSQL, Git, Express.js, Web Development, GitLab, Software Architecture, Project Consultancy, Full-stack Development, Front-end Development, Shopify, Remote Team Leadership, Figma, DNS, Design, Front-end Architecture, REST APIs, Design Patterns, D3.js, Data Visualization, Data Processing, Mobile Development, Microsoft Teams, Slack App, eCommerce, Software Design, Scalability, Performance, Cloud, Integration, Serverless Architecture, MERN Stack, CSS3, Webpack, JSON, Babel, Responsive Web Design (RWD), SaaS, Back-end, CI/CD Pipelines, Responsive Design, Unit Testing, Cross-browser Compatibility, Vercel, Progressive Web Applications (PWA), SQL, UI Components, Design Systems, Marketing, Deployment, Mobile First, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, QR Codes, Heroku, Context API, Databases, Event-driven Architecture, Lambda Architecture, Software Engineering, Software Documentation, Technical Architecture, Business Analysis, Dashboards, Auth0, Google Cloud Functions, Data Extraction, Solution Architecture, Requirements Analysis, ETL, Data Modeling, Agile Sprints, On-page SEO, Technical SEO, Website Audits, Axios

Lead Software Engineer

2022 - 2022
Raise Financial
  • Recreated the company's existing Ruby platform in React, Next.js, and Prisma, matching functionality one-to-one.
  • Communicated with stakeholders effectively, summarizing current progress, estimates, and potential risks to delivery.
  • Consulted the CTO on product direction and technical evaluation of key deliverables.
  • Integrated payments using Stripe and Plaid APIs, designing complex logic involving the custom generation and parsing NACHA files.
  • Added new UI components using React and Tailwind CSS.
Technologies: JavaScript, Responsive UI, Puppeteer, Node.js, Next.js, MVP Design, Strategy, IT Strategy, Agile Delivery, CTO, Team Leadership, Prisma, Stripe, Stripe API, ACH, Plaid, Plaid API, Payment APIs, Server-side Rendering (SSR), Storybook, Jest, API Integration, Search Engine Optimization (SEO), MySQL, Technical Leadership, Amazon Web Services (AWS), Amazon CloudFront CDN, Content Delivery Networks (CDN), Cypress, Leadership, Git, Express.js, Web Development, CSS3 Animation, Chakra UI, Single-page Applications (SPA), Software Architecture, Project Consultancy, Full-stack Development, Front-end Development, Ruby on Rails (RoR), Remote Team Leadership, Figma, DNS, Design, Front-end Architecture, Full-stack, REST APIs, Design Patterns, D3.js, Data Visualization, Data Scraping, Data Processing, Data Science, Mobile Development, Microsoft Teams, Slack App, Scraping, Software Design, Scalability, Cloud, Integration, Docker, Serverless Architecture, MERN Stack, CSS3, JSON, Babel, Responsive Web Design (RWD), SaaS, Back-end, CI/CD Pipelines, JSON Web Tokens (JWT), Responsive Design, Unit Testing, Cross-browser Compatibility, Vercel, Progressive Web Applications (PWA), Fintech, SQL, UI Components, Design Systems, Mobile First, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, Heroku, Context API, Databases, Event-driven Architecture, Lambda Architecture, Software Engineering, Software Documentation, Technical Architecture, Business Analysis, Dashboards, Auth0, Gmail API, OpenAI, Data Extraction, Solution Architecture, Requirements Analysis, ETL, Data Modeling, Agile Sprints, Ruby, Website Audits, Amazon S3 (AWS S3), Axios

Full-stack Software Engineer

2021 - 2022
Deutsche Bank
  • Created a multi-department release management system using React, Material-UI, CSS, Redux, and MongoDB.
  • Owned the project from start to finish, managed other developers, and handled communication with stakeholders.
  • Maintained test coverage at 100% throughout development, resulting in zero production issues encountered since release.
Technologies: JavaScript, TypeScript, Java, React, MongoDB, PostgreSQL, Redux, Google Cloud Platform (GCP), Python 3, Python, Chart.js, Git, Express.js, Web Development, Single-page Applications (SPA), Software Architecture, Full-stack Development, Front-end Development, Figma, Front-end Architecture, Full-stack, REST APIs, Design Patterns, D3.js, Data Processing, Microsoft Teams, Software Design, Scalability, Cloud, Integration, Serverless Architecture, MERN Stack, CSS3, JSON, Babel, Responsive Web Design (RWD), SaaS, Back-end, CI/CD Pipelines, Responsive Design, Unit Testing, Progressive Web Applications (PWA), Fintech, SQL, UI Components, Design Systems, Mobile First, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, Context API, Databases, Event-driven Architecture, Lambda Architecture, Software Engineering, Software Documentation, Technical Architecture, Dashboards, Google Cloud Functions, Solution Architecture, Requirements Analysis, Data Modeling, Agile Sprints, Axios

Full-stack Software Engineer

2019 - 2020
JPMorgan Chase
  • Developed a complex analytics web application for senior management using TypeScript, React, CSS, and Jira API. This tool became the most significant priority for 2020 in my line of business.
  • Volunteered to code a data integrity checker for reference data which was previously populated and checked manually, reducing the workload of two teams by multiple hours each week.
  • Implemented real-time monitoring and alerting to improve the application's stability, halving the number of production issues encountered in the following two months.
Technologies: Bitbucket, Node.js, React, JavaScript, TypeScript, Chart.js, Git, Express.js, Web Development, Single-page Applications (SPA), Full-stack Development, Front-end Development, Full-stack, REST APIs, Design Patterns, Data Processing, Microsoft Teams, Software Design, Scalability, Cloud, Integration, CSS3, JSON, Babel, Back-end, Responsive Design, Fintech, SQL, UI Components, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, Databases, Software Engineering, Software Documentation, Dashboards, Requirements Analysis, Data Modeling, Agile Sprints, Axios

Release Notifier

A React application for a Fortune 500 bank that manages communication between stakeholders and developers.

I developed and led the project, managing other developers, achieving the deliverable ahead of schedule. I was able to maintain code coverage at 100% throughout development.

This project was built with TypeScript, React, MongoDB, and Material-UI. It connects to a Java backend and PostgreSQL via REST API.

Winfluencer.io

https://winfluencer.io
An application built with React, Node.js, Firebase, Material-UI that uses the YouTube API to fetch and analyze millions of videos to discover trending topics relevant for creators and help them make content aligned with their audience's interests. The blog for this site was built using Next.js.

I built this app from start to finish, managed team members, and acquired customers. I used CI/CD on Google Cloud to implement continuous deployment and separate testing environments. I also implemented bundle optimization and lazy loading to 10x performance, leading to significant SEO improvements.

Raise Financial | Next.js Application

https://www.raisefinancial.com
A Next.js application that I rebuilt from scratch to migrate it from Ruby. I worked on both the front and back ends. Also, I successfully executed the migration to Next.js, including development, testing, and effective communication, and launched it with no downtime.

Database of 7 Million Open Source Developers | RealGreatDevs

https://www.realgreatdevs.com
I created the world's largest database of open source developers, currently with over seven million developers and more than one million developers with email addresses. I wrote custom scrapers to gather this information quickly and cost-effectively. I am currently scraping at a rate of 150,000 new developers per day. I created 50,000 unique SEO results pages, which are getting thousands of impressions on Google.
2017 - 2021

Bachelor's Degree with First Class Honors in Computer Science

University of Bath - United Kingdom

Libraries/APIs

Node.js, React, Stripe API, Chart.js, REST APIs, D3.js, Social Media APIs, Context API, Gmail API, React Testing Library, Puppeteer, Stripe, Plaid API, Shopify API, Slack API, Google Maps API, Salesforce API, Playwright, React DnD

Tools

GitHub, Bitbucket, Prisma, Git, GitLab, Figma, Microsoft Teams, ChatGPT, Webpack, Plaid, Trello, Babel, Auth0, BigQuery, Zapier, Slack, Amazon CloudFront CDN, Seos, Google Analytics

Frameworks

Material UI, Next.js, Tailwind CSS, Redux, OAuth 2, Express.js, JSON Web Tokens (JWT), Jest, Cypress, Svelte, Ruby on Rails (RoR)

Languages

JavaScript, TypeScript, CSS, HTML, ECMAScript (ES6), HTML5, SQL, CSS3, Python 3, Python, C, Assembly, Java, GraphQL, PHP, C#, Ruby

Paradigms

Agile, Continuous Integration (CI), Microservices, Design Patterns, Mobile Development, Serverless Architecture, Responsive Web Design (RWD), Unit Testing, Lambda Architecture, Requirements Analysis, On-page SEO, Management, REST, Search Engine Optimization (SEO), Data Science, Event-driven Architecture, ETL, DevOps, Responsive, Off-page SEO

Platforms

Visual Studio Code (VS Code), Google Cloud Platform (GCP), AWS Lambda, Vercel, Firebase, Shopify, Mobile, Amazon Web Services (AWS), Docker, Heroku, Web, Azure, Salesforce

Storage

MySQL, NoSQL, JSON, Elasticsearch, Databases, Google Cloud, MongoDB, PostgreSQL, Amazon S3 (AWS S3), Amazon DynamoDB, Cloud Firestore

Industry Expertise

Social Media, Marketing

Other

Communication, Software Development, Architecture, CTO, Consulting, Cloud Infrastructure, System Architecture Design, Server Architecture, Front-end, Back-end, User Interface (UI), User Experience (UX), APIs, Server-side Rendering (SSR), Web Scraping, Storybook, API Integration, Technical Leadership, Serverless, Authentication, OAuth, Autoscaling, Web Development, CSS3 Animation, Single-page Applications (SPA), Software Architecture, Project Consultancy, Full-stack Development, Front-end Development, OpenAI GPT-4 API, DNS, Front-end Architecture, Data Scraping, OpenAI GPT-3 API, Data Visualization, Data Processing, Slack App, Scraping, Software Design, Scalability, Cloud, Integration, MERN Stack, SaaS, CI/CD Pipelines, Responsive Design, Supabase, Progressive Web Applications (PWA), Fintech, UI Components, Design Systems, Mobile First, Digital Payments, Card Payments, Stripe Payments, Payment Gateways, Software Engineering, Software Documentation, Technical Architecture, Business Analysis, Dashboards, OpenAI, Google Cloud Functions, Data Extraction, Solution Architecture, Data Modeling, Agile Sprints, Technical SEO, Website Audits, Axios, Financial Data, Full-stack, Responsive UI, Team Leadership, ACH, Payment APIs, Animation, Leadership, Headless Commerce, Machine Learning, Artificial Intelligence (AI), Vectors, Chakra UI, Remote Team Leadership, Design, Toolkits, eCommerce, Performance, Slackbot, Cross-browser Compatibility, Google BigQuery, Mentorship, Cloudflare, Web Marketing, B2C Marketing, Advertising, Milestones, Roadmaps, Startups, Strategy, MVP Design, IT Strategy, Agile Delivery, Server Infrastructure, Infrastructure, Monday.com, Framer, UI Animation, Firebase Cloud Functions, Content Delivery Networks (CDN), Generative Pre-trained Transformers (GPT), HubSpot CRM, Deployment, QR Codes, NextAuth.js, PWA, SEO Tools, programmatic seo, Vercel Analytics, Google Search Console, Google Analytics 4, Sitemaps, Linked Data, Programmatic SEO

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