Marat K. — Full-stack, Ruby on Rails Engineer / Team Lead / CTO

Expertise in Full Stack Web.

Last verified on March, 2026

Core Skills

Bio Summary

- Experienced full-stack web developer and team lead with a solid knowledge of strategies, patterns, and technologies.
- Proven experience and expertise in building and maintaining full-stack applications, adept at both backend and frontend development using technologies such as Ruby on Rails, Elixir, Phoenix, JavaScript, React.js, and Go.
- Proficient in configuring cloud architectures using AWS CDK scripts and deploying applications to cloud services such as AWS and GCP
- Extensive background in backend API development, including building messaging platforms, digital contracts signing platforms, and social network MVPs using technologies like Elixir, Phoenix, and GraphQL API.
- Strong database architecting and management expertise, with hands-on experience in PostgreSQL, Redis, and other database technologies, contributing to efficient data storage and retrieval.
- Demonstrated leadership as a CTO, leading teams, setting strategic goals, managing team dynamics
- Upper-Intermediate English

Technical Skills

Programming Languages	C, C++, Delphi, Elixir, Java, JavaScript, Ruby
JavaScript Frameworks	jQuery, React
Ruby Frameworks	Ruby on Rails
Databases & Management Systems / ORM	AWS ElasticSearch, Microsoft SQL Server, MS Access, MySQL, PostgreSQL, Redis
UI Frameworks, Libraries, and Browsers	jQuery, Phoenix
Cloud Platforms, Services & Computing	GCP
Amazon Web Services	AWS ElasticSearch
QA, Test Automation, Security	BugZilla, Mantis
Version Control	CVS, Git, GitHub, GitLab, SVN
Virtualization, Containers and Orchestration	Docker, Kubernetes
Operating Systems	Fedora, macOS, Windows
Collaboration, Task & Issue Tracking	Jira
Deployment, CI/CD & Administration	Mantis
SDK / API and Integrations	RESTful API
Web/App Servers, Middleware	Windows NT

Experience

Backend Engineer, Panion.org

11/2021-present

Responsibilities:

Building electric cars fleet management platform using Ruby on Rails
Implementing the new features with RoR
Configuring the cloud architecture using AWS CDK scripts
Making architectural decisions on code and server setup
DB architecting
Refactoring old code
Doing code reviews

Technologies: Ruby on Rails, AWS, PostgreSQL, Redis, Docker.

Backend API Engineer, Turn.io

04/2020-08/2021

Responsibilities:

Building a messaging platform on top of WhatsApp using Elixir GraphQL API and React
Implementing the new features with Elixir
DB architecting
Refactoring old code
Doing code reviews

Technologies: Elixir, Phoenix, React, GCP, PostgreSQL, Redis, Docker, ElasticSearch.

Backend API Engineer, Contractbook.com

10/2019-04/2020

Responsibilities:

Building digital contracts signing platform using Elixir and React
Implementing the new features with Elixir
Refactoring old code
DB architecting
Doing code reviews

Technologies: Elixir, Phoenix, React, AWS, PostgreSQL, Redis, Docker, Heroku.

Backend API Engineer, Mindvalley Connect

05/2019-07/2019

Responsibilities:

Building social network MVP using Elixir backend with GraphQL API from scratch
Implementing the backend with Elixir
DB architecting
Architecting the codebase, implementing the features, doing code reviews

Technologies: Elixir, Phoenix, PostgreSQL, Redis, Docker, GCP.

Backend Engineer, Provide Technologies Inc

01/2019-08/2019

Responsibilities:

Building AWS automatic deployment engine.

Technologies: Golang, AWS.

CTO, 3Taps.com

04/2018-02/2019

Responsibilities:

Planning teamwork, setting strategy goals, team management
Rebuilding the old RoR application backend using Elixir/Phoenix/OTP
Building multiple frontend sites using pure JavaScript, jQuery, React.js representing backend data
Building geolocation data JS engine

Technologies: Elixir, Phoenix, JavaScript, React.js, PostgreSQL, ElasticSearch, Redis.

Chief of Ruby on Rails department, Svitla Systems Inc.

04/ 2012 – 04/2018

Responsibilities:

Client communication
Planning teamwork
High-level application design
Code quality assurance
Giving talks at tech conferences.
Training and mentoring other talkers.

Technologies: Ruby on Rails v.3, v.4, JavaScript, React.js, PostgreSQL, MySQL, Redis.

Senior Ruby Engineer, Svitla Systems Inc.

08/ 2007 – 2012

Responsibilities:

Managing web-application development team:
Planning teamwork
High-level application design
Code quality assurance

Technologies: Ruby on Rails v.3, MySQL, SQLite

Senior RoR Developer, Svitla Systems Inc.

01/07 – 10/07
Common tasks: Web application development, planning, testing

Technologies: Ruby on Rails, MySQL, SQLite

Java developer in the UP2P programming team, Panasonic Inc.

01/06 – 01/07

Responsibilities:

Development of the UP2P messaging visualizer running on DHT: GUI, XML-RPC
Development of the chat/voice communicator utility

Technologies: Java

Projects

CTO, team lead, architect, developer.3taps.com

Description: http://docs.3taps.com/

Multiple services to support classified ads collecting, storing, indexing, and giving authorized access.
Scraping service with dynamic scraper creation. http://scraper.3taps.com/
Proxy finder service which collects proxies from several locations.
Posting API engine with the ability to produce 5M inserts per day (ruby) and now even more because Elixir is faster.
Polling API service allows clients to poll data they need with given parameters.
Search API service, which allows clients to perform full-text annotated searches.
Matcher API service which allows clients to search for specific 3taps posting through the HYPERLINK "https://bikeindex.org/" https://bikeindex.org/ database.
Custom-built geolocation representation of backend data http://globe.3taps.com/

Technologies: RoR, Elixir/Phoenix, JavaScript, React.js.

Team lead, developer.Airbnb attestor

Description: https://attestations.3taps.com/

Services that check Airbnb account affiliation. The user gets a confirmation code from API on their mobile device screen and enters it into their profile. The service then checks their page periodically and verifies that the account belongs to the user.

Technologies: Elixir, Node.js, lightweight Elixir API on AWS, node.js service which sends requests to API.

DB architect, developer, Mindvalley Connect

Description: https://mindvalley.com/

The backend of the social network for the main Mindvalley application users.

Technologies: Elixir/Phoenix, GraphQL API on GCP.

DB architect, developer, Contractbook.com

Description: https://contractbook.com/

The backend of the online work agreement solution.

Technologies: Elixir/Phoenix, React.

Developer, Provide Technologies

Description: https://provide.services/

The backend of the automatic containers deployment to AWS.

Technologies: Go.

Ooma.com user portal

Description: User portal that allows ooma.com users to change their account settings, buy products, change subscriptions, see call logs, etc. Integration with 3rd party services and inner Ooma services working as XML-RPC, SOAP, and REST APIs.

Technologies: ruby, javascript, jQuery, React, full-stack RoR web application with RoR backend, React UI.

Education

NTUU "KPI", Kyiv, Ukraine

Specialty: Computer-Aided Design

Faculty: Electronics

Degree: master of computer science, diploma with distinction

Open International University of Human Development "Ukraine", Kyiv, Ukraine

Specialty: computer technologies

Degree: bachelor of computer science, diploma with distinction

Courses included discrete mathematics, numerical methods, probability theory, mathematical models and complex system optimization, mathematical statistics, theory of control and decision-making, estimation and identification methods, CAD systems, adaptive and intelligent control systems, reliability and efficiency analysis, database design, net information technologies, operating and programming systems, computer architecture, engineering graphics, computer graphics, theory translators and compilers, logical and functional programming, Web-design

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