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Serhii – Ruby, Ruby on Rails, Redis, experts in Lemon.io

Serhii

From Ukraine (GMT+3)

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Back-end Web DeveloperSenior
Hire developer
7 years of commercial experience
Automotive
Entertainment
Environmental services
Fintech
Platforms
SaaS
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Serhii – Ruby, Ruby on Rails, Redis

Serhii is a backend developer specializing mainly in Ruby on Rails. With over 5 years of commercial experience, he is proficient in all software development life cycle phases, including requirements gathering, analysis, design, implementation, maintenance, and testing of software applications. Serhii is dedicated to continuous learning and has worked across various domains, including entertainment, e-commerce, fintech, and more!

Main technologies
Ruby
5 years
Ruby on Rails
5 years
Additional skills
Redis
PostgreSQL
jQuery
JavaScript
Sidekiq
JSON API
Capybara
MySQL
Vue.js
AWS
SASS
Kafka
GraphQL
Microservices
Ready to start
ASAP
Direct hire
Potentially possible

Experience Highlights

Senior Ruby on Rails developer
Aug 2022 - Jul 202311 months
Project Overview

It is the employee rewards and recognition platform for the modern workplace. It enables companies to reward top employees with memorable, personal, and shareable experiences. Experiences as rewards not only provide a more meaningful avenue for employee recognition, but also create a lasting impact on your top engagement metrics (like increased employee motivation and retention rates, and providing a more positive company culture).

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Responsibilities:

• Worked on experiential rewards & recognition platform as a Ruby on Rails developer. • Worked with GraphQL to develop endpoints • Developed Ruby on Rails micro service for internal tool with Kafka(Karafka) integration. • Worked on rails library updates. • Closed tech debts related to the code refactoring. • Worked on performance optimizations for endpoints • Got experience with dry.rb libraries such as dry-schema, dry-validation, dry-monads

Project Tech stack:
Ruby on Rails
PostgreSQL
Kafka
GraphQL
Microservices
Senior Ruby on Rails developer
Feb 2020 - Aug 20222 years 6 months
Project Overview

It is a reseller shop software that handles the automated sending of invoices and offers payment methods. One of the biggest fin-tech platforms in the DACH region.

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Responsibilities:
  • Got experience with the Vue.js framework.
  • Developed delivery feature for logisticians.
  • Developed promo code feature from scratch.
  • Developed upgrade/downgrade subscription feature with Stripe.
  • Upgraded version of Stripe API integration for the whole project.
  • Worked on performance optimizations related to database queries and also to the page speed up.
  • Developed in short terms shop feature, that adds the possibility to create for users their own custom shops with custom domain.
Project Tech stack:
Ruby on Rails
JavaScript
Vue.js
Redis
PostgreSQL
SASS
Sidekiq
Strong Middle Ruby on Rails developer
Jun 2019 - Apr 202010 months
Project Overview

It is the largest e-commerce project in Switzerland for creating car event presentations and concerts. Includes an admin panel for creating events, a custom checkout page, and a presentation page.

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Responsibilities:
  • Added tests(integration/unit) from scratch to the legacy e-commerce project, it gained test coverage to 90%.
  • Made improvements that speed up admin panel pages using raw SQL queries and refactoring of existing ones.
  • Refactored parts of codebase using service objects, presenters, query objects.
  • Wrote service that generates excel files from a raw SQL query and gives nice statistics. This service was 5 times faster than the previous implementation.
  • Implemented one master project for 15 projects that have different features inside like payment systems and creation of events.
  • Upgraded rails from unstable beta version to version 4.2, upgraded ruby and gem dependencies.
  • Solved database migrations for 15 projects that were combined in a single master project.
  • Implemented from scratch Saferpay payment system for the master project. This helped to dropped the rails engine and one custom gem dependency.

Project Tech stack:
Ruby on Rails
JavaScript
jQuery
Capybara
PostgreSQL
saferpay
Full-stack Ruby on Rails developer
Aug 2018 - Jun 201910 months
Project Overview

Internal project for collecting ticketing data from various resources and consolidating event data. As a company was an owner of the stadiums worldwide, they decided to create their internal service for creating events and concerts.

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Responsibilities:
  • Developed the project from scratch as a Full-stack developer
  • Got experience with Ember JS framework.
  • As a frontend developer I worked on implementing features and covering all pages with tests.
  • Created custom queries for the backend as we used JSON API.
  • Added custom error handler to the whole project with notifications.
  • As a backend developer, I created the database schema, added CRUD for API.
  • Developed services that used Sidekiq for activation/deactivation of old tickets.
  • Covered the whole backend with the request, model, and unit tests.
  • Added automation tests using WebdriverIO

Project Tech stack:
Ember.js
Ruby on Rails
MySQL
Redis
JavaScript
Sidekiq
JSON API
webdriver.io
Ruby on Rails developer
May 2017 - Sep 20181 year 4 months
Project Overview

The project has real-time green compliance dashboards, instant verification of green building products, and the ability to track carbon and ESG metrics. It simplifies sustainability by providing solutions to make it easier for green construction projects to be built on time and on budget.

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Responsibilities:
  • Added query objects to optimize the query to a database.
  • Speeded up pages that had complex queries with AJAX calls. Added tests.
  • Refactored fat controllers with service objects.
  • Worked mainly on performance optimization for the project.
  • Added new features and maintained the whole project.
  • Added tests to the existing functionality.
Project Tech stack:
Ruby on Rails
jQuery
PostgreSQL
Redis
JavaScript
Sidekiq

Education

2013
Social Pedagogue
Master degree

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