Yerassyl Diyas, Developer in Almaty, Almaty Province, Kazakhstan
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Yerassyl Diyas

Verified Expert  in Engineering

Full-stack Software Developer

Almaty, Almaty Province, Kazakhstan
Toptal Member Since
August 20, 2021

Yerassyl is a full-stack software developer with around four years of experience working with startups. His primary expertise is Ruby, Rails, and React. He improved project deployment and built time from 20 to five minutes, created core functionality from zero to beta to the start of sales, and built core front-end and administration dashboard UIs. Yerassyl loves using new technologies to optimize features and create products that make people's lives easier and more organized.


AMN Healthcare - Main
Ruby on Rails (RoR), Heroku, React, Test-driven Development (TDD), Docker...
Ruby, Ruby on Rails (RoR), JavaScript, React, Node.js, Webpack...
Node.js, TypeScript, React, PostgreSQL, GraphQL, Amazon S3 (AWS S3)...




Preferred Environment

MacOS, RubyMine, WebStorm

The most amazing... time I improved was from 20 to five minutes by switching to the new app library Puma and fixing critical caching issues that caused 50% load increases.

Work Experience

Ruby on Rails Developer

2021 - 2022
AMN Healthcare - Main
  • Worked on the existing large codebase and added new features or enhancements and code refactoring.
  • Documented the existing codebase written by developers who departed from the company.
  • Handled support tickets on demand, fixed edge case issues, performed root cause analysis, and fixed data corruptions.
Technologies: Ruby on Rails (RoR), Heroku, React, Test-driven Development (TDD), Docker, Amazon S3 (AWS S3), Next.js, Sidekiq, Back-end, PostgreSQL

Full-stack Software Developer

2018 - 2021
  • Worked in a large legacy full-stack monolith app, refactored old code, improved developer happiness, and implemented new features.
  • Moved the CSS processing from an asset pipeline to Webpack. Improved developer happiness.
  • Improved project deployment and build time from 20 to 5 minutes. Faster deployments led to faster feature testing on review apps.
  • Migrated maps from Google to Open Street Maps and migrated assets (JavaScript and CSS) to S3 with versioning. Reduced costs.
  • Implemented review apps to make testing easier and moved old JavaScript and jQuery code to React. Improved code maintainability.
Technologies: Ruby, Ruby on Rails (RoR), JavaScript, React, Node.js, Webpack, Amazon S3 (AWS S3), Heroku, Test-driven Development (TDD), Docker, Sidekiq, Back-end, CI/CD Pipelines, PostgreSQL

Full-stack Software Developer

2018 - 2018
  • Developed core back-end APIs for web and mobile.
  • Built core front-end and administration dashboard UIs.
  • Developed an Android app for gathering data about potential customers.
Technologies: Node.js, TypeScript, React, PostgreSQL, GraphQL, Amazon S3 (AWS S3), Amazon Web Services (AWS), Back-end, CI/CD Pipelines, Python

Full-stack Software Developer

2017 - 2017
  • Created core functionality from zero to beta and then to the start of sales with a team of developers.
  • Developed core back-end services, booking appointments, doctor search, feedback, and SMS approval tools.
  • Built front-end and inner applications: On-line schedule, operators and call-center dashboard, and a doctor profile.
  • Participated in making business UX design-related decisions primarily by researching similar start-ups in other countries.
  • Consulted patients via phone (this helped to understand functional requirements for the call-center application).
Technologies: JavaScript, React, PostgreSQL, Back-end, Python

Keep It Fresh

Keep It Fresh is a cosmetic bag on your phone. Keep track of your products, expiration dates, share feedback with friends, and take a look at what your friends or celebrities use. Share what is inside your cosmetic bag with your friends.


JavaScript, Ruby, HTML, CSS, Python, TypeScript, GraphQL, Haml


Ruby on Rails (RoR), Tailwind CSS, Next.js, Stimulus


MacOS, Heroku, Docker, Amazon Web Services (AWS)


PostgreSQL, Databases, Redis, Amazon S3 (AWS S3)


Programming, Software Engineering, Web Development, Back-end, Chakra UI, Hotwire, CI/CD Pipelines


React, Node.js, Sidekiq


RubyMine, WebStorm, Webpack, Turbo


Object-oriented Programming (OOP), Functional Programming, Test-driven Development (TDD)

2013 - 2017

Bachelor's Degree in Computer Science

Nazarbayev University - Nur-Sultan, Kazakhstan

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