Cristian Butiri, Developer in Cluj-Napoca, Cluj County, Romania
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Cristian Butiri

Verified Expert  in Engineering

Full-stack Developer

Cluj-Napoca, Cluj County, Romania
Toptal Member Since
February 5, 2021

Cristian is a passionate full-stack software developer with more than seven years of experience in the field. He is mostly interested in back-end technologies such as Ruby on Rails or Go but is also committed to creating user-friendly interfaces, having more than two years of experience with React. As an open-minded person, Cristian enjoys productive discussions, which lead to finding the best solution for any possible problem.


Wolfpack Digital SRL
Amazon S3 (AWS S3), Amazon Web Services (AWS), APIs, API Development...
&Open Gifts Ltd
Ruby, Ruby on Rails (RoR), React, Amazon Web Services (AWS), GitLab CI/CD
Toptal Clients
Ruby on Rails (RoR), Amazon Web Services (AWS)...




Preferred Environment

MacOS, Visual Studio Code (VS Code), iTerm2

The most amazing...

...project I've worked on is converting an old MVC architecture to REST APIs, through which I managed to optimize loading times from 20 to around three seconds.

Work Experience

Senior Software Developer

2023 - PRESENT
Wolfpack Digital SRL
  • Developed a social media platform that allows users to rate different celebrities, reaching a user base of 10,000 users.
  • Mentored four interns and one junior developer in learning Ruby on Rails by building a new web app and an API from scratch.
  • Held a successful presentation about integrating Elasticsearch in Rails to scale large applications with more than 100,000 users.
  • Tracked the issues and performance of a social media app using Sentry and Amazon CloudWatch.
Technologies: Amazon S3 (AWS S3), Amazon Web Services (AWS), APIs, API Development, API Integration, Back-end Development, Ruby on Rails (RoR), Ruby

Ruby on Rails Engineer

2022 - 2023
&Open Gifts Ltd
  • Improved the admin portal of the web app to allow customer support to fix 30% more issues without technical assistance.
  • Contributed to upgrading Ruby 2.7 to 3.0 and improving code style through RuboCop.
  • Developed new features that improved the end user experience by customizing them for two additional countries.
Technologies: Ruby, Ruby on Rails (RoR), React, Amazon Web Services (AWS), GitLab CI/CD

Senior Full-stack Developer

2021 - 2022
Toptal Clients
  • Designed and developed a new web app from the ground up to manage more than 100 clients' campaigns and offers for various mobile games and apps, using Ruby on Rails 6 and React 17+.
  • Integrated the new app with existing systems, using AWS's SQS by sending and processing messages to and from the queue, handling a throughput of more than 1,000 messages daily.
  • Created a real-time notification system to inform users of certain messages processed through the SQS queue using web sockets.
  • Handled production deployments and maintenance of the web app and took part closely with the PM and the clients in establishing new features for the app.
  • Implemented a support page for users that would send e-mail messages through AWS SES and Slack via a Slack API whenever a bug or feature request was reported.
  • Kept a test coverage of at least 90% throughout the entire lifetime of the web app.
  • Maintained the latest library versions, including replacing Webpacker with shakapacker and upgrading Material UI v4 to Material UI v5.
  • Created a cron job responsible for parsing the play store, retrieving new info about around 300 apps, and updating existing data daily.
Technologies: Ruby on Rails (RoR), Amazon Web Services (AWS), Amazon Simple Queue Service (SQS), Amazon S3 (AWS S3), Slack API, PostgreSQL, Material UI, Back-end Development, Software Development, Web Development, React, JavaScript, HTML5, CSS3, Redux, Back-end, Front-end, JSON Web Tokens (JWT), API Development, Full-stack Development, Next.js, API Integration, MongoDB, User Experience (UX), User Interface (UI), Databases, CSS, HTML, Responsive Web Design (RWD)

Senior Software Engineer

2021 - 2021
Freelance via Toptal
  • Improved error tracking and the time required for debugging by adding new relevant details to the context of the errors reported.
  • Refactored the classes used to parse webpages by extracting the common functionality into a superclass and using inheritance and composition.
  • Converted several pages and components written in Stimulus to React to improve code readability and page loading times.
Technologies: Ruby, Ruby on Rails (RoR), React, RSpec, Back-end Development, Software Development, Web Development, JavaScript, Ruby on Rails 5, HTML5, CSS3, Redux, Back-end, Front-end, API Development, Full-stack Development, API Integration, Amazon Web Services (AWS), User Interface (UI), User Experience (UX), Databases, CSS, HTML, Responsive Web Design (RWD)

Team Lead

2021 - 2021
Take Off Labs
  • Managed a team of three developers, two juniors and one senior, to release five new functionalities.
  • Created specifications and reports for five new features for a widely used golf tournament management application.
  • Reviewed and tested code for various functionalities used by thousands of users.
Technologies: Jira, Google Docs, Google Sheets, Software Development, Web Development, Full-stack Development, Databases

Senior Software Engineer

2019 - 2021
Take Off Labs
  • Developed a REST API used by iOS and Android mobile apps. The app was built to allow golf players to register for events and track their scores.
  • Converted a classic Haml Ruby page to React components and improved the response times from about 30 seconds to three seconds per request using caching, pagination, and other optimization methods.
  • Built an integration system with a different provider to synchronize the golf players' data from their system with the data in our system. Sync for each player was also made when signing in through the SSO system.
  • Created a new functionality called Player Dashboard using React and Ruby on Rails. Thousands of users use this page daily.
  • Extended the member profile page with two new pages loaded asynchronously through AJAX requests.
  • Created new background jobs when longer or more complex computations were needed.
Technologies: Ruby on Rails (RoR), Jira, Back-end Development, Software Development, Web Development, React, JavaScript, Ruby on Rails 5, HTML5, CSS3, APIs, Redux, Back-end, Front-end, API Development, Full-stack Development, API Integration, User Interface (UI), User Experience (UX), Bootstrap, Databases, CSS, HTML, Heroku, Responsive Web Design (RWD)

Junior Java Developer

2017 - 2019
  • Developed an internal management tool for the HR department to track the interview processes for new internship candidates. The technology stack included Java, Angular, PostgreSQL, and CQRS as an architecture.
  • Helped develop a B2B eCommerce platform for tracking orders to and from multiple physical stores, using Java and Angular.
  • Built a small Hybris application for training purposes.
Technologies: Java, Angular, PostgreSQL, Docker, Back-end Development, Software Development, Web Development, HTML5, CSS3, APIs, Back-end, Front-end, JSON Web Tokens (JWT), API Development, Full-stack Development, Databases, CSS, HTML

Junior Developer

2016 - 2017
Take Off Labs
  • Developed an MVC RoR application for tracking investment portfolios, together with an API and an iOS mobile app with the same purpose.
  • Contributed to the responsiveness and redesign of multiple pages using CSS and Bootstrap.
  • Researched various GitHub integrations to create a dashboard for tracking issues and PRs.
Technologies: Ruby on Rails (RoR), Back-end Development, Software Development, Web Development, JavaScript, HTML5, CSS3, Back-end, Front-end, JSON Web Tokens (JWT), API Development, Full-stack Development, API Integration, User Interface (UI), User Experience (UX), Bootstrap, Databases, CSS, HTML, Heroku

Toptal Node.js Accelerator

The Node.js Accelerator is an exclusive learning program that educates JavaScript / Backend developers in Node.js, ExpressJs, NestJS, and TypeScript. This is a 2-month program that consists of rigorous learning exercises, live instructor-led sessions by SMEs, hands-on activities along with a stringent evaluation process, comprehensive assessments, and an incremental project where participants implement a couple of microservices (REST APIs) using ExpressJs and NestJs. The Incremental project simulates an eCommerce application consisting of two services, i.e., a User service to implement the authentication with user management and a product-catalog service that offers functionalities to manage inventory.

Algorithms Learning App

An application primarily based on React lets users create step-by-step animations for explaining various algorithms. The users could also create an account, new animations, or search and watch algorithm explanations created by other users. Animations were created frame by frame by dragging and dropping various elements, and each frame would store the coordinates and other data related to the elements. All the properties would be transitioned smoothly to the next step, creating a nice and useful animation.

Golf Club App

A Swift-based iOS and Java-based Android mobile application with a RESTful Ruby on Rails API that allows golf players to register and keep scores for different events.

I was mainly accountable for the back-end part of the app, extending the existing login method and adding new functionalities such as checking in for an event, adding different scores, etc. This project's main challenge was adapting the existing architecture to the new requirements requested by the clients, which I managed to solve by using design patterns, strategies, and adapters.

Member Page for Golf Tournament Management App

An application based on Ruby on Rails using sharded databases for managing golf clubs and associations.

I was a full-stack developer in charge of improving the performance of the members' list page by converting the classical MVC pattern into a more modern RESTful architecture with a React-based front-end. I worked with well-known React libraries such as React Redux and react-virtualized for this project. I managed to improve load times for the back end by splitting large queries into smaller ones, caching data wherever possible, and applying pagination with infinite loading in the front end.
2015 - 2018

Bachelor's Degree in Computer Science

Babes-Bolyai University - Cluj-Napoca, Romania


Toptal Node.js Accelerator Graduate

Toptal, LLC


React, REST APIs, API Development, Slack API, Node.js, jQuery


Git, GitHub, RSpec, Amazon Simple Queue Service (SQS), Jira, Google Docs, Google Sheets, GitLab CI/CD


Ruby on Rails (RoR), Ruby on Rails 5, Material UI, Redux, JSON Web Tokens (JWT), Bootstrap, Angular, NestJS, Express.js, Next.js


JavaScript, SQL, Ruby, CSS, HTML, HTML5, CSS3, Python 3, Java, Swift, Python, TypeScript, WASM


Responsive Web Design (RWD), Design Patterns, Scrum


PostgreSQL, Databases, JSON, Amazon S3 (AWS S3), MongoDB, NoSQL


MacOS, Visual Studio Code (VS Code), Docker, Amazon Web Services (AWS), Heroku


Software Development, Web Development, APIs, Full-stack, Back-end Development, Back-end, Front-end, Full-stack Development, API Integration, iTerm2, User Interface (UI), User Experience (UX)

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