Evgenii Pecherkin, Back-end Developer in Montreal, Canada
Evgenii Pecherkin

Back-end Developer in Montreal, Canada

Member since September 7, 2022
Evgenii is a hard-working, dedicated team player and an experienced back-end engineer. He has more than 11 years of practical experience, including everything about software development, design, integration, and solving all kinds of issues, as well as creating new systems from scratch and supporting and updating legacy systems. He provides reliable performance, as well as transparent and effective communication.
Evgenii is now available for hire


  • FazzMe
    Node.js, TypeScript, React, PostgreSQL, Docker, Kubernetes...
  • Toptal
    Ruby, Ruby on Rails (RoR), Microservices, PostgreSQL, Jenkins, Agile...
  • Online Freelance Agency
    Ruby, Ruby on Rails (RoR), PostgreSQL, MySQL, MongoDB, React...



Montreal, Canada



Preferred Environment

Ruby on Rails (RoR), PostgreSQL, Docker, TypeScript, React, Linux, GitHub, Jira, Slack, Agile

The most amazing...

...thing I've achieved is a noticeable contribution to the performance and stability of Toptal's platform.


  • Chief Technology Officer

    2021 - 2022
    • Researched, compared, and selected tools and technologies to create the product and designed the system's architecture, taking into account the price of cloud services and expected user growth and business direction.
    • Developed several essential parts of the application, such as integration with a blockchain, moderation, and admin modules, as well as CI/CD pipelines.
    • Led a 4-person engineering team to release the product to production four months from the start.
    • Contributed to the building of product vision from a raw idea. Proposed several ideas and solutions, which turned out to be essential for the business. Some of these solutions were patented later.
    Technologies: Node.js, TypeScript, React, PostgreSQL, Docker, Kubernetes, Google Kubernetes Engine (GKE), Google Cloud Platform (GCP), Blockchain, Agile, CI/CD Pipelines, Jira, Slack, GitHub, Blockchain Platforms, Customized Blockchains, Git, Vim Text Editor, Stripe, Stripe API, Stripe Checkout, APIs, GraphQL, Ethers.js, Ethereum, Non-fungible Tokens (NFT), System Design, Scaling, Performance, Debugging, CQRS, OOP Designs, API Architecture, JavaScript, Stripe Connect, Stripe Payments, Stripe Connect API, API Integration, API/Services Architecture, Unix, Optimization, IT Management, Team Leadership, Remote Team Leadership, Analytics, Research, Microservices, Microservices Architecture, CTO, Front-end, Back-end, HTML, CSS, Full-stack, Jest
  • Core Senior Back-end Developer

    2016 - 2021
    • Made CI 30% faster and cheaper, saving thousands of hours of CI time and more than $10,000 per month. For that, I created a new tool to execute RSpec tests and Cucumber features in a parallel distributed manner, controlling through DRb protocol.
    • Improved overall performance of the application by tracking down and fixing multiple bottlenecks using Grafana, Kibana, and flame graphs.
    • Improved the user experience by reworking a part of the interface from Ruby on Rails views to React.
    • Reworked legacy Delayed Job jobs to Active Job, and refactored them to fit best practices of the industry.
    • Reduced the complexity of working with jobs by introducing a whole new concept of serializers into Active Job. It was merged into Active Job itself later.
    • Increased consistency and fault tolerance of the system by introducing a new abstraction level to represent business transactions during the execution of business processes. That includes data with complex dependencies on external systems.
    • Optimized RAM consumption of Cucumber suite by using object caching in factories.
    • Developed a regression test selection library for RSpec. It builds a dependency tree from test files to source files, which is used to select and execute specific tests based on what source files have been changed.
    Technologies: Ruby, Ruby on Rails (RoR), Microservices, PostgreSQL, Jenkins, Agile, CI/CD Pipelines, Jira, Sidekiq, Redis, Slack, GitHub, Grafana, Kibana, Git, NGINX, Amazon Web Services (AWS), GitHub API, APIs, GraphQL, REST APIs, CQRS, System Design, OOP Designs, API Integration, Domain-driven Design (DDD), Test-driven Development (TDD), GitFlow, Microservices Architecture, API Architecture, API/Services Architecture, Node.js, Python 3, Django, Vim Text Editor, Linux, Unix, Debugging, Performance, Optimization, Apache Kafka, Front-end, Back-end, HTML, CSS
  • Senior Ruby, Ruby on Rails, and React Developer

    2014 - 2016
    Online Freelance Agency
    • Updated legacy file management system from Ruby 1.8 to 2.7, reworked it to fit best practices of the industry, and made the management of files 30% faster by introducing Active Job and Sidekiq and handling several processes concurrently.
    • Improved performance and reduced complexity of a legacy Backbone and jQuery application by reworking it to React.
    • Implemented a real-time chat for a social network using WebSockets.
    • Implemented a tracking subsystem with the idea of not interfering with the main application in any way. It was achieved by introducing a new Ruby microservice and complex configuration of Nginx.
    Technologies: Ruby, Ruby on Rails (RoR), PostgreSQL, MySQL, MongoDB, React, ECMAScript (ES6), ES7, Node.js, Agile, CI/CD Pipelines, GitHub, Slack, Sockets, NGINX, Git, JavaScript, Stripe, Stripe API, Stripe Checkout, APIs, REST APIs, GraphQL, Debugging, Optimization, Performance, API Design, System Design, API/Services Architecture, Linux, Unix, Docker, Stripe Connect, Stripe Marketplace, Stripe Connect API, OOP Designs, Analytics, Research, GitHub API, GitFlow, Vim Text Editor, Microservices, Microservices Architecture, Front-end, Back-end, HTML, CSS, Full-stack, Jest
  • Ruby on Rails Developer

    2013 - 2014
    • Reworked and improved the performance of a subsystem that processes ongoing business tasks by using a custom processor for Delayed Job, increasing from 100 tasks per hour to up to 1,000 tasks per hour.
    • Doubled the performance of full-text search in the system by the integration of Elasticsearch.
    • Educated and supervised junior developers to ensure they were a good fit and could keep up with the quality and performance requirements of the main team.
    • Developed a microservice-based system using a variety of technologies to upload, transform, store, and stream videos, images, and audio.
    Technologies: Ruby, Ruby on Rails (RoR), Docker, PostgreSQL, Redis, Sidekiq, Data Processing, CI/CD Pipelines, Agile, Elasticsearch, Streaming, Sockets, NGINX, Git, JavaScript, Stripe, Stripe API, Stripe Checkout, APIs, API/Services Architecture, API Design, GraphQL, Vim Text Editor, Linux, Unix, Socket Programming, Microservices, Microservices Architecture, MySQL, Front-end, Back-end, HTML, CSS
  • Software Engineer

    2012 - 2013
    • Initiated a new sub-department for cross-platform mobile development using Xamarin, which brought in a significant profit in the first months.
    • Designed an abstraction layer for Google Maps to be used by Xamarin iOS and Android.
    • Improved performance and user experience of several mobile applications significantly by handling data management concurrently.
    Technologies: C#.NET, C#, Xamarin, C++, iOS, Android, Windows Phone, Agile, Objective-C, Objective-C++, Git, APIs


  • Social Network on Blockchain

    I joined this project when there was nothing but an idea in the client's head. He wanted to create a new social network where any user could make money right off their personal content.

    Such an idea required us to build a system with high security, transparency, and trustfulness. Here I proposed that blockchain technologies can help us achieve that. I figured out a new concept of working with blockchains and NFTs, which is patented now.

    After two months of intense work, I clarified requirements and business vision, prepared a specification and architecture design for the project, and built a development team for it. We went with microservices and Kubernetes for scaling.

    Since I was the most experienced development team member, I took on the most complex tasks. In the meantime, I managed the other three developers, helped them solve issues, and worked with the marketing team to clarify requirements and direction.

    This approach allowed us to release the product four months after the start, doing things quickly, not forgetting about best practices such as code quality, documentation, tests, and CI/CD. The system was launched and started to bring income within three months.

  • Contactless Business Card with Custom Design

    During COVID-19 times, my friend and I figured out an idea of a service we could provide for business people and artists of Montreal.

    We researched what people are looking for, who competitors are, and what we can offer. We used a progressive web app solution to bypass Google Play and Apple Store limitations and fees and share users' business cards with just a link, which magically converts to an application.

    I designed the system's architecture, configured hosting on Google Cloud, and created the back end with Ruby on Rails. In addition, I found and managed a UI designer and several Ionic 4 developers to build the application's front end.

  • Toptal Platform

    For more than five years, I worked as a part of Toptal's core team, contributing to developing and improving an enterprise product. I was surrounded by a large team of top-level developers. I was also a part of a small sub-team of experts whose job was to find and fix performance issues, improve the quality of life for the entire platform, and research paths of potential evolution for it.

    I mainly worked with Ruby, digging deep into Rails and several other libraries. My contribution resulted in a significant performance and stability increase, as well as a redesign of several parts of the system.

    But it wasn't only about Ruby and Rails—I learned a lot about other technologies and solutions, including Python, Django, Jenkins, Kibana, and Grafana.


  • Languages

    Ruby, TypeScript, SQL, JavaScript, GraphQL, C++, ECMAScript (ES6), ES7, C#.NET, C#, Objective-C, Python, Python 3, HTML, CSS3, CSS
  • Frameworks

    Ruby on Rails (RoR), Ionic, Django, Jest
  • Tools

    GitHub, Vim Text Editor, Git, Slack, NGINX, Jira, Google Kubernetes Engine (GKE), Jenkins, Grafana, Kibana, Stripe Checkout
  • Paradigms

    Object-oriented Programming (OOP), Agile, Test-driven Development (TDD), Microservices Architecture, API Architecture, API/Services Architecture, Microservices, CQRS, Socket Programming
  • Platforms

    Linux, Unix, Docker, Blockchain Platforms, Kubernetes, Google Cloud Platform (GCP), Blockchain, Xamarin, iOS, Android, Windows Phone, Amazon Web Services (AWS), Ethereum, Apache Kafka
  • Other

    Program Development, APIs, OOP Designs, API Integration, Domain-driven Design (DDD), GitFlow, API Design, System Design, CI/CD Pipelines, Data Processing, Customized Blockchains, Non-fungible Tokens (NFT), Scaling, Performance, Debugging, Stripe Payments, Optimization, IT Management, Team Leadership, Remote Team Leadership, Streaming, Objective-C++, Progressive Web Applications (PWA), Ethers.js, Analytics, Research, Stripe Marketplace, CTO, Front-end, Back-end, Full-stack
  • Libraries/APIs

    Node.js, Sidekiq, Stripe, Stripe API, REST APIs, Stripe Connect, React, Sockets, GitHub API, Stripe Connect API
  • Storage

    PostgreSQL, Redis, MySQL, MongoDB, Elasticsearch, MySQL Server


  • Engineer's Degree in Computer and Information Sciences and Support Services
    2009 - 2014
    Ulyanovsk State Technical University - Ulyanovsk, Russia

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