Oleg Gorbunov, Developer in Kiev, Ukraine
Oleg is available for hire
Hire Oleg

Oleg Gorbunov

Verified Expert  in Engineering

Bio

Oleg is an experienced full-stack engineer with 15+ years in software development, specializing in Ruby on Rails and React. Passionate about clean code, performance optimization, and scalable architectures, he has a proven track record of leading teams, mentoring developers, and delivering mission-critical features for startups and enterprises. Oleg is committed to open-source and modern development practices

Portfolio

Procore Technologies Inc.
Ruby on Rails (RoR), Ruby, React, Elasticsearch, PostgreSQL, Redis, Weather API...
VarageSale
Amazon Web Services (AWS), JavaScript, SQL, Microservices, Fluentd, Sidekiq...
WinOrLose
JavaScript, Redux, Firebase, Cordova, React, GitHub, Git, RSpec...

Experience

  • JavaScript - 15 years
  • SQL - 14 years
  • Ruby on Rails (RoR) - 14 years
  • Ruby - 14 years
  • Amazon Web Services (AWS) - 11 years
  • Microservices - 10 years
  • React - 8 years
  • React Native - 2 years

Availability

Part-time

Preferred Environment

MacOS, Visual Studio

The most amazing...

...initiative I've led on my own saved the company $200,000 per year by optimizing API costs.

Work Experience

Senior Ruby on Rails/React Developer

2019 - 2025
Procore Technologies Inc.
  • Saved $200,000 per year by switching to a different weather provider (recognizing overpay, investigating alternatives, creating POCs, developing and implementing steps of migration).
  • Owned Permissions and Weather domains as a person with the highest expertise.
  • Built PSL for connectivity between different Tools in Procore's ecosystem.
  • Created integration between the equipment beta tool and daily log in two weeks while the previous team worked on it for six months without success.
  • Handled debugging of production-specific issues without direct access.
  • Performed migration of ERB pages to MFE application successfully.
  • Mentored team from the new Cairo office to ensure their work aligned with best practices.
  • Participated and won prizes in the company's hackathon.
  • Performed setup of architecture for new functionality for the team as the best who can minimize complexity.
Technologies: Ruby on Rails (RoR), Ruby, React, Elasticsearch, PostgreSQL, Redis, Weather API, GitHub, Git, RSpec, REST APIs, Microservices, CSS, HTML

Full-stack Developer (via Toptal)

2019 - 2019
VarageSale
  • Reengineered the implementation of ads to make it more performant, reliable, and extensible.
  • Contributed to solving app bottlenecks in high-load areas.
  • Added new functionality for a member support microservice.
  • Migrated emails from Mailgun to SendGrid email delivery solution.
  • Made the app less coupled to the notifications microservice.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Microservices, Fluentd, Sidekiq, MySQL, Ruby on Rails (RoR), Ruby, React, GitHub, Git, RSpec, REST APIs, CSS, HTML

Lead Developer (via Toptal)

2018 - 2019
WinOrLose
  • Supported the web desktop, web mobile, iOS, and Android platforms.
  • Built an MVP in two months, including Web desktop, Web mobile, Android, and iOS apps.
  • Developed a sophisticated feed algorithm to ensure relevant cases for everyone.
  • Implemented real-time updates, chat, payments, voting, commenting, filtering, authorization flow, settings, and profile.
  • Worked on the full cycle of the build, deployment, and push to the Google Play and App Store.
Technologies: JavaScript, Redux, Firebase, Cordova, React, GitHub, Git, RSpec, Firebase Realtime Database, Firebase Authentication, Firebase Hosting, REST APIs, CSS, HTML

Chief Architect

2018 - 2018
BidWrangler
  • Solved the n+1 issue, which had acted as the server bottleneck.
  • Created an "auction progress" feature to observe the auction state over time.
  • Collaborated remotely with a team spread across the US, Ukraine, Poland, and Portugal; used GitHub, Slack, and Zoom.
  • Increased test coverage from 75% to 90% to enhance app reliability.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, AWS Elastic Beanstalk, Google Places API, Capybara, Stripe, Firebase, Google Maps, Airbrake, Material UI, Redux-Saga, Redux, Webpack, MySQL, Ruby on Rails (RoR), React, GitHub, Git, RSpec, REST APIs, Microservices, CSS, HTML

Full-stack Developer

2016 - 2018
Clade
  • Developed the front-end of an admin tool app (React).
  • Implemented a Clubhouse-GitHub integration to sync the development state.
  • Consulted on the back-end of a GraphQL server's maintenance and set up.
  • Created a mechanism for universal email templates for SendGrid synchronization and customization.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Heroku, HockeyApp, Fastlane, Prismic, Google Places API, SendGrid, Litmus, Surge Proxy Server, Karma, Draft.js, Styled-components, Redux Form, Redux-Saga, Redux, GraphQL, Apollo, Webpack, Node.js, React Native, React, TypeScript, GitHub, Git, REST APIs, Microservices, CSS, HTML

Team Leader

2016 - 2017
Watchtower
  • Worked remotely with a team in the US; used Trello, Slack, and Skype to communicate.
  • Conducted code reviews for other developers and managed assignments.
  • Solved performance issues for the main page with a heavy functionality.
  • Created the architecture for the front-end of a web application with real-time updates.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, Heroku, Webpack, ECMAScript (ES6), React-Bootstrap, Redux-Saga, CSS, Redux, React, Capistrano, PostgreSQL, Ruby on Rails (RoR), GitHub, Git, REST APIs, HTML

Front-end Developer

2016 - 2016
A Job Board for Freelance Work
  • Implemented a freelancer onboarding flow in React.
  • Provided support for video interviews using the 3rd-party provider.
  • Implemented designs according to material design guidelines.
  • Developed Payoneer integrations and a massive payment management tool.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Redux, Heroku, Webpack, ECMAScript (ES6), Material UI, Redux Form, Redux-Saga, CSS, React, GitHub, Git, REST APIs, Microservices, HTML

Senior Full-stack Developer

2015 - 2016
Chairlift
  • Upgraded the application from Rails 3 to Rails 4 to be on edge of techs.
  • Designed and integrated an extensible ACL system with 100% coverage of endpoints on top of Pundit.
  • Migrated React front-end application to a SPA architecture.
  • Increased the readability and comprehensiveness of the application by 100% by cleaning up more than 100,000 lines of legacy code.
Technologies: JavaScript, SQL, Ruby, Cucumber, RSpec, Material UI, MySQL, Gulp, React, Polymer, Ruby on Rails (RoR), GitHub, Git, REST APIs, CSS, HTML

Full-stack Developer

2013 - 2015
LevelUp
  • Worked as a semantic algorithms domain leader to achieve target goals.
  • Increased the performance of a keyword tree generation 550 fold by inventing a new algorithm, optimizing SQL queries, and intensively using a caching approach.
  • Migrated a product from Padrino to Ruby on Rails 4.
  • Increased the collection rate from 500 to 50,000 keywords/hour by optimizing the database usage, using a Redis cache, improving the process flow, and separating concerns.
Technologies: Amazon Web Services (AWS), JavaScript, SQL, Ruby, RSpec, Sidekiq, MongoDB, Redis, PostgreSQL, Knockout (Knockout.js), Sinatra, Ruby on Rails (RoR), GitHub, Git, CSS, HTML

Lead Developer

2012 - 2013
Cowries Bills
  • Set up an integration with the Stripe payment service.
  • Created multi-wallet support for international customers.
  • Implemented a background multi-process service to handle highly sensitive data.
Technologies: JavaScript, SQL, Ruby, Stripe, Clickatell, Heroku, PostgreSQL, Ruby on Rails (RoR), GitHub, Git, RSpec, Stripe API, CSS, HTML

Full-stack Web Developer

2012 - 2013
3taps
  • Increased the performance from 100 to 400 requests per second.
  • Developed an API protocol for microservices communication.
  • Implemented search, filter, sort, statistics, preview, and favorites modules.
Technologies: JavaScript, SQL, MySQL, Backbone.js, Ruby on Rails (RoR), Ruby, GitHub, Git, CSS, HTML

Full-stack Web Developer

2011 - 2012
DOCOMO
  • Implemented calculation and management of different leave types for employees in all countries, places, and time zones.
  • Worked as a reports domain owner and supported and developed new features.
  • Installed a state machine to handle the leaves state flow.
Technologies: JavaScript, SQL, jQuery, PostgreSQL, Ruby on Rails (RoR), Ruby, CSS, HTML

Experience

BidWrangler

https://www.bidwrangler.com
This is a mobile bidding platform for auctioneers that allows you to engage bidders on their smartphones as well as on your website. Imagine your bidders downloading and using your app to bid in your auctions. It is simple to use for both you and your bidders.

Chairlift

Chairlift empowers your managers and employees with a robust solution to collect various types of real-time 360-degree feedback.

Features:
• Conduct a 360° evaluation of yourself
• Conduct a 360° evaluation of any employee you supervise
• Obtain feedback consistently throughout the year
• Keep track of your one-to-one meetings
• Exchange feedback on a group project
• Give or ask for feedback with your email software

WatchTower

WatchTower provides software that improves quality, transparency, and communication between brokers and carriers. We take the messy, complicated RFP process and simplify it down to a few steps, saving you from lost time and crispy hair. Say goodbye to the endless emails, disparate notes and edits, and disorganized spreadsheets of 1995, and say hello to a solution that lifts you into the cloud.

Clade

https://clade.co
A private club for investors, philanthropists, and collectors to connect with their peers on a global scale. Members use Clade to share and advance their personal goals, both business and charitable. These objectives range broadly from launching new bespoke venture funds to promoting NGOs focused on maternal health in the developing world.

A Job Board for Freelance Work

I helped develop a global marketplace of prescreened, top freelance software engineers and digital designers. Our world-class engineers and designers have worked with some of the biggest technology companies in the world, including Google, Microsoft, Facebook, Apple, and many others. The site's clients include Fortune 500 companies such as PepsiCo and Pearson and famous venture-backed startups such as Gwyneth Paltrow's Goop.com.

Education

2007 - 2013

Master's Degree in Economic Cybernetics

Tavrida National V.I. Vernadsky University - Simferopol, Ukraine

Skills

Libraries/APIs

Sidekiq, Redux-Saga, Redux Form, React, REST APIs, jQuery, Clickatell, Google Places API, Google Maps, Stripe, Backbone.js, Polymer, Stripe API, Node.js, Filestack

Tools

RSpec, GitHub, Git, Firebase Authentication, Gulp, Capistrano, Airbrake, Fluentd, Fastlane, Litmus, Karma, SendGrid, Cucumber, Webpack, Visual Studio, React Apollo

Languages

Ruby, JavaScript, CSS, ECMAScript (ES6), TypeScript, HTML, GraphQL, SQL

Frameworks

Ruby on Rails (RoR), React Native, Redux, Material UI, React-Bootstrap, Draft.js, Capybara, Sinatra, Knockout (Knockout.js), Flux

Paradigms

Microservices, Database Design

Platforms

Firebase, Amazon Web Services (AWS), MacOS, AWS Elastic Beanstalk, Heroku, HockeyApp

Storage

MySQL, PostgreSQL, MongoDB, Redis, Firebase Realtime Database, Elasticsearch

Other

Firebase Hosting, Apollo, Surge Proxy Server, Styled-components, Prismic, Cordova, CSS Modules, Weather API, Graph Theory, Game Theory, Combinatorics, Probability Theory, Data Structures, Algorithms

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring