Sebastian is available for hire
Hire SebastianSebastian Buza
Verified Expert in Engineering
Full-stack Developer
Location
London, United Kingdom
Toptal Member Since
February 1, 2018
Sebastian is a talented software engineer whose systems are used by millions of people globally. His expertise in programming and development has led to the creation of highly effective and widely utilized software solutions in various industries. His work, particularly in web technologies and application development, has made a significant impact worldwide.
Portfolio
ScoutIQ LLC
Ruby on Rails (RoR), React, MySQL, Full-stack, MongoDB, Firebase, TypeScript...
Torstar
Ruby on Rails (RoR), React, Node.js, PostgreSQL, Full-stack, JavaScript Testing...
Procore
Ruby on Rails (RoR), React, Ruby, PostgreSQL, Node.js, JavaScript, Full-stack...
Experience
Availability
Part-time
Preferred Environment
GitHub, Git, RubyMine, Linux, Ruby, Ruby on Rails (RoR), React, Node.js
The most amazing...
...system I developed at Procore integrates multiple React apps in Ruby on Rails, boosting front-end developer efficiency by 50%.
Work Experience
Lead Software Engineer
2021 - 2023
ScoutIQ LLC
- Transitioned our application to the latest Ruby on Rails framework (version 7.0), ensuring seamless compatibility with cutting-edge technologies and adherence to the highest security standards.
- Worked with the client between 2021 and 2023, and my strategic initiatives and contributions played a key role in expanding ScoutIQ's customer base from 700 to 5,000 customers.
- Upgraded Ruby to version 3.1, significantly boosting the speed and reliability of our application. This enhancement translates to faster, more stable service for our users, facilitating quicker book reselling transactions.
- Overhauled the front-end dashboard by adopting the Vite React framework with hooks, resulting in a markedly more responsive and intuitive user interface. This change not only enhances the user experience but also streamlines our development process.
- Completely rebuilt our dashboard from scratch, focusing on a design that is more aligned with our users' needs. This redesign enhances functionality, making it easier for users to manage and flipbooks effectively.
- Integrated advanced data visualization tools using Cube dev charts combined with React, Firebase events, and MongoDB. This integration provides users with powerful analytics and reporting features, enabling them to make informed decisions.
- Consistently addressed software issues and introduced new features, significantly elevating the overall application functionality and user satisfaction. This commitment to excellence ensures that ScoutIQ Co. remains a top choice for book resellers.
Technologies: Ruby on Rails (RoR), React, MySQL, Full-stack, MongoDB, Firebase, TypeScript, JavaScript Testing, RSpec, Redux, React Router, jQuery, CSS, Linux, RubyMine, JavaScript, PostgreSQL, Redis, SQL, HTML5, Git, Elasticsearch, Axios, Optimization, Capistrano, Sidekiq, Rake, Lodash, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Ruby on Rails API, JSON, Rack, Pair Programming, Object-relational Mapping (ORM), HTML, Redux Thunk, React Native, GraphQL, jQuery UI, JRuby, Sinatra, GitHub, Material UI, ImageMagick, NGINX, Kotlin
Lead Software Engineer
2020 - 2020
Torstar
- Seamlessly integrated the most recent version of React Create APP into our existing Rails 4 framework. This strategic update significantly enhances front-end functionality, offering Tostar.com users a more fluid and engaging experience.
- Introduced a new front-end system at Torstar, which significantly optimized our workflows, leading to a remarkable 30% improvement in efficiency for our team members. This enhancement has streamlined processes and boosted productivity.
- Employed advanced tools like React Router, Redux, Thunk, and Hooks to develop a front-end architecture that is not only robust and scalable but also efficient. This ensures Torstar users enjoy a responsive and reliable interface.
- Crafted responsive React components using Material-UI design principles, focusing on creating an intuitive and visually appealing user interface. This design approach enhances the aesthetic appeal, increasing user interaction and satisfaction.
- Played a crucial role in shifting from a traditional Rails-and-jQuery framework to a more modern Rails API and React architecture. This transition was executed with minimal user disruption, maintaining a consistent, high-quality experience.
- Continuously updated and maintained key gems in the Rails application, ensuring the platform operated at peak performance and security. This dedication to excellence provides our users with a reliable and secure platform.
- Successfully set up and deployed tostar.com to a new staging environment, showcasing our expertise in deployment strategies and environment management. This capability ensures that our platform is robust and adaptable to meet evolving business needs.
Technologies: Ruby on Rails (RoR), React, Node.js, PostgreSQL, Full-stack, JavaScript Testing, RSpec, Redux, React Router, CSS, Linux, RubyMine, JavaScript, Ruby on Rails 5, Redis, SQL, HTML5, Materialize, Git, Elasticsearch, Axios, Optimization, Capistrano, Stimulus, Sidekiq, Rake, Lodash, Antd, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Chef, Ruby on Rails API, TypeScript, JSON, Rack, Pair Programming, Object-relational Mapping (ORM), HTML, Redux Thunk, JRuby, Sinatra, GitHub, Material UI, Concurrent Programming, ImageMagick, JSON-LD, NGINX, SEO Tools
Lead Software Engineer
2017 - 2020
Procore
- Developed a system that seamlessly integrated multiple independent React applications within a single Rails framework, utilizing both technologies' strengths.
- Executed critical enhancements in the application's database management, effectively minimizing the occurrence of deadlocks. This resulted in a substantial boost in database performance and reliability.
- Achieved a significant acceleration in API response times by employing optimized coding practices and efficient resource management. This enhancement made the application more responsive and user-friendly.
- Addressed and resolved a critical system issue related to NIL-related errors, showcasing my strong problem-solving abilities and commitment to software quality.
- Played an active role in the team's migration to API versioning. This strategic move ensures the application's adaptability and long-term scalability, which are vital for evolving financial and payment functionalities.
- Oversaw the upgrade and enhancement of the payment services module, focusing on improving the efficiency and security of transactions. This is crucial in a platform like Procore, where financial transactions are a key component.
- Spearheaded the integration of React across various pages, ensuring uniformity in performance and a cohesive user experience.
- Implemented advanced performance optimization techniques in React components, leading to quicker load times and overall improved application efficiency.
- Worked closely with the UI/UX team to ensure React components adhered to design standards, providing an optimal user experience across different platforms.
Technologies: Ruby on Rails (RoR), React, Ruby, PostgreSQL, Node.js, JavaScript, Full-stack, JavaScript Testing, RSpec, Redux, React Router, Svelte, jQuery, CSS, Linux, RubyMine, Ruby on Rails 5, Redis, MongoDB, SQL, HTML5, Materialize, Git, Axios, Optimization, Capistrano, Sidekiq, Rake, Lodash, Antd, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Chef, Ruby on Rails API, TypeScript, JSON, Rack, Pair Programming, Object-relational Mapping (ORM), HTML, Redux Thunk, Cordova, JRuby, Sinatra, GitHub, Vue, Actor Programming, Material UI, Concurrent Programming, ImageMagick, NGINX
Lead Software Engineer
2018 - 2019
BitLab BVBA
- Engineered a robust API using Rails and GraphQL, ensuring efficient data handling and seamless integration with front-end components.
- Developed dynamic front-end components utilizing the ANT design system, enhancing the application's visual appeal and user experience.
- Integrated Redux with React Router and hooks, optimizing state management and navigation within the application.
- Led and coordinated the back-end development team, streamlining workflow and ensuring project milestones were met effectively.
- Innovated in GraphQL development by employing metaprogramming techniques, significantly reducing the need for boilerplate code. Additionally, pioneered the development of a custom library to facilitate this process.
- Implemented an automated system for generating documentation for GraphQL endpoints, improving code maintainability and developer onboarding.
- Organized and managed the development team using the Atlassian board, enhancing team collaboration and project tracking.
Technologies: React, JavaScript, Firebase, Full-stack, Ruby, Ruby on Rails 5, Ruby on Rails (RoR), JavaScript Testing, RSpec, Redux, React Router, GraphQL, jQuery, CSS, Linux, RubyMine, PostgreSQL, Redis, Node.js, MongoDB, SQL, HTML5, JavaScript MVC, Materialize, Git, Elasticsearch, Axios, Optimization, Capistrano, Sidekiq, Cloud Firestore, Rake, Lodash, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Chef, Ruby on Rails API, TypeScript, JSON, Rack, Pair Programming, Object-relational Mapping (ORM), HTML, Sinatra, GitHub, FFmpeg, Concurrent Programming, ImageMagick, NGINX
Full-stack Developer
2017 - 2018
Ourea Systems
- Enhanced the performance and efficiency of multiple sub-services utilizing Ruby, significantly improving the application's reliability and functionality.
- Streamlined the developer workflow by integrating Docker, Heroku, and CircleCI, facilitating continuous integration and deployment processes.
- Spearheaded improvements in front-end features using Ember.js, leading to an enhanced user interface and user experience.
- Developed a system for generating PDF reports from HTML content using the wkhtmltopdf command-line tool, providing users with high-quality, easily accessible reports.
- Implemented effective tracking mechanisms for monitoring the status of background jobs, ensuring timely execution and system reliability.
Technologies: JavaScript, Ember.js, Ruby on Rails (RoR), Ruby, Full-stack, Heroku, CircleCI, JavaScript Testing, RSpec, Ember FastBoot, jQuery, CSS, Linux, RubyMine, Ruby on Rails 5, PostgreSQL, Redis, Node.js, MongoDB, SQL, HTML5, JavaScript MVC, Socket.IO, Git, Elasticsearch, Ember CLI, WebSockets, Axios, Optimization, Capistrano, Sidekiq, Cloud Firestore, Rake, Lodash, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Chef, Ruby on Rails API, JSON, Rack, Ember Data, Pair Programming, Object-relational Mapping (ORM), HTML, Sinatra, GitHub, Concurrent Programming, ImageMagick, NGINX
Lead Software Engineer
2016 - 2017
Skupos
- Set up and configured the Rails application, database, and Nginx server, demonstrating expertise in server management and deployment, and successfully deployed the entire infrastructure to AWS.
- Developed a robust back-end API using JSON API resources, ensuring efficient data handling and seamless integration with front-end components.
- Implemented advanced security measures in the back end using CanCanCan and developed a custom-built, private gem for tracking changes and enhancing application security and data integrity.
- Created Rake tasks for importing sample data, significantly aiding developers during the application development.
- Implemented comprehensive authentication systems and user invitations and integrated Google Analytics for insightful user behavior tracking and application analytics.
- Integrated a sophisticated single-page application theme purchased from ThemeForest, significantly enhancing the application's visual appeal and user experience.
- Developed front-end services for fetching CSRF tokens and monitoring user online statuses, improving application security and real-time user interaction capabilities.
- Engineered background jobs for synchronizing the database with convenience store (c-store) inventory, ensuring accurate and up-to-date inventory management.
- Pioneered the development of an electronic application specifically tailored for convenience stores, facilitating inventory syncing and management.
- Created custom services for implementing Ajax queries to the back end using Ember.js services and jQuery, ensuring efficient and dynamic data exchange.
Technologies: Ember.js, JavaScript, Ruby on Rails (RoR), Ruby, Full-stack, React, JavaScript Testing, RSpec, JRuby, Ember FastBoot, jQuery, CSS, Linux, RubyMine, PostgreSQL, Redis, Node.js, MongoDB, SQL, HTML5, JavaScript MVC, Socket.IO, Git, Ember CLI, WebSockets, Optimization, Capistrano, Sidekiq, Cloud Firestore, Rake, Software Engineering, Engineering Software, Design Principles, CI/CD Pipelines, APIs, SCSS, Mocha, Chef, Ruby on Rails API, JSON, Rack, Ember Data, Pair Programming, Object-relational Mapping (ORM), HTML, Sinatra, GitHub, Concurrent Programming, ImageMagick, NGINX
Full-stack Developer
2014 - 2016
Crewmeister
- Led the design and implementation of the API using the JSONAPI-resources gem, catering specifically to the Ember.js front-end, ensuring seamless data exchange and application functionality.
- Enhanced the back-end security by integrating Pundit for operation authorization and Papertrail for tracking model changes, significantly improving data integrity and application security.
- Initiated and implemented a strategic workflow change, transitioning to Capistrano for code deployment and employing Chef for server configuration, optimizing the deployment process and server management.
- Developed a custom calendar component for managing holiday schedules, utilizing Moment.js for accurate time range computations and enhancing the application's user interface and functionality.
- Ensured application internationalization (i18n) throughout the development process, preparing the application for broader use outside of Germany and enhancing its global usability.
Technologies: Ruby, Ruby on Rails (RoR), Ember.js, React, PostgreSQL, Redis, APIs, JSON, JavaScript Testing, RSpec, Ember FastBoot, jQuery, CSS, Full-stack, Linux, RubyMine, JavaScript, Node.js, MongoDB, SQL, HTML5, JavaScript MVC, Socket.IO, MySQL, Git, Ember CLI, WebSockets, Optimization, Sidekiq, Rake, Software Engineering, Engineering Software, CI/CD Pipelines, SCSS, Mocha, Chef, Ruby on Rails API, Rack, Ember Data, Object-relational Mapping (ORM), HTML, Windows, Sinatra, GitHub, ImageMagick, NGINX
Junior Developer
2012 - 2014
Hiscore
- Developed and maintained websites using WordPress, demonstrating proficiency in CMS management and web content optimization.
- Built simple yet effective websites from scratch utilizing HTML, JavaScript, and jQuery, showcasing my front-end development and user interface design skills.
- Gained hands-on experience with Meteor, a full-stack JavaScript platform, contributing to developing real-time web applications.
- Learned and applied Ruby on Rails, enhancing my capabilities in full stack development and understanding of MVC architecture.
- Undertook hardware-related tasks, including assembling PCs from scratch, which honed my technical problem-solving skills and understanding of computer hardware.
- Demonstrated a keen ability to adapt to various technologies and tasks, showing versatility and a commitment to continuous learning in software development.
Technologies: PHP, Ruby, Ruby on Rails (RoR), HTML, CSS, JavaScript Testing, RSpec, jQuery, Full-stack, Linux, PostgreSQL, Redis, SQL, HTML5, Java 8, Git, Organic SEO, Sidekiq, Rake, Software Engineering, Engineering Software, WordPress, Ruby on Rails API, Rack, Ember Data, Object-relational Mapping (ORM), Windows, GitHub, ImageMagick, NGINX
Experience
Skupos
http://skupos.comSkupos is a B2B inventory and order management app for convenience stores. It streamlines operations with real-time tracking, database syncing, and intuitive interfaces for inventory, ordering, and sales analytics. It's a comprehensive retail solution designed for efficiency and ease of use.
Scoutiq
https://www.scoutiq.co/ScoutIQ is a book reselling and flipping app offering tools for scanning, evaluating, and pricing used books. It aids resellers in making informed decisions with real-time data, streamlining the process of finding profitable books for resale.
Procore
https://www.procore.com/Procore is a cloud-based construction management software company. It provides an integrated platform that connects teams, applications, and devices in a central workspace. The software offers solutions for project management, construction financials, quality and safety, and field productivity, aiming to streamline project communication and documentation, thereby increasing efficiency and reducing risk across the project lifecycle. Procore is designed to be user-friendly and accessible on mobile and desktop devices, making it a versatile tool for professionals in the construction industry.
Torstar
https://torstar.comTorstar Corporation, a prominent Canadian media company, is known for publishing news through various platforms. Its operations include the Daily News Brands division, which primarily comprises the Toronto Star and associated properties like The Hamilton Spectator and the Waterloo Region Record.
Ourea Systems
https://www.oureasystems.com/Ourea Systems offers a technology solution named Ourea OneView™, designed to power wealth management businesses. This data engine aims to deeply understand clients, identify future propositions, and automate account management. OneView is built to integrate directly with major wealth product providers and existing CRMs, providing uniform, seamless data across all products and providers.
Crewmeister
https://crewmeister.com/en/Crewmeister is a cloud-based solution designed specifically for small businesses, offering employee time tracking and absence management. It simplifies the process of tracking working times and managing absences with features like real-time tracking, automatic data transfer to Excel, and a user-friendly timesheet app.
Skills
Languages
CSS, SQL, HTML, JavaScript, JRuby, SCSS, Ruby, HTML5, GraphQL, Kotlin, Java 8, TypeScript, PHP
Frameworks
Ruby on Rails 5, JavaScript MVC, Ember.js, Ruby on Rails (RoR), Svelte, Stimulus, Redux, React Native, Sinatra, Material UI, Materialize
Libraries/APIs
React, ImageMagick, Rack, Ruby on Rails API, Node.js, Ember Data, jQuery, Ember FastBoot, Sidekiq, React Router, Antd, Lodash, jQuery UI, Socket.IO, FFmpeg, Vue
Tools
Git, GitHub, NGINX, Mocha, RubyMine, JavaScript Testing, Rake, Capistrano, RSpec, Redux Thunk, Chef, CircleCI
Paradigms
Object-relational Mapping (ORM), Concurrent Programming, Pair Programming, Actor Programming
Platforms
Linux, Windows, Firebase, Heroku, WordPress
Storage
Cloud Firestore, JSON, MySQL, PostgreSQL, Redis, MongoDB, Elasticsearch, JSON-LD
Other
Full-stack, Google Cloud Functions, Organic SEO, Ember CLI, WebSockets, SEO Tools, Optimization, Axios, APIs, CI/CD Pipelines, Design Principles, Engineering Software, Software Engineering, Cordova
Education
2016 - 2018
Master's Degree in Software Engineering
West University of Timișoara - Timișoara, Romania
2014 - 2016
Bachelor's Degree in Computer Science
West University of Timișoara - Timișoara, Romania
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