Elena-Cristina is available for hire
Hire Elena-CristinaElena-Cristina Conacel
Verified Expert in Engineering
Full-stack Developer
Bucharest, Romania
Toptal member since September 3, 2020
Bio
Cristina has over a decade of experience founding and building startups across multiple fields. Most notably, she founded Creative Tim, a developer tools startup that reached over 500,000 users. She's a full-stack developer passionate about Ruby on Rails, responsive web design, and modern JavaScript frameworks. Cristina has experience working in cross-functional teams and taking products from idea to launch and beyond.
Portfolio
VeloVostra
Ruby on Rails 7, Tailwind CSS, Claude Code, Replit, Heroku
Clarytas
Python, React, Next.js, ChatGPT API, Claude Code, AI Agents
Get Clear Consulting Ltd
Ruby on Rails (RoR), JavaScript, HTML, CSS, Less, Capistrano, Ansible...
Experience
- HTML - 10 years
- JavaScript - 10 years
- Bootstrap - 10 years
- User Interface (UI) - 10 years
- SCSS - 10 years
- Web Architecture - 10 years
- Ruby on Rails (RoR) - 10 years
- React - 4 years
Work Experience
Founder
2025 - PRESENT
VeloVostra
- Built and launched velovostra.com from my mobile phone using Replit.
- Stayed current with AI advancements in software development, leveraging the latest AI-powered tools and workflows to accelerate the build process and maintain a modern, efficient development approach.
- Acquired over 100 initial users, validating the product's market fit and demonstrating the ability to drive early traction and build a user base.
- Built on a modern tech stack using the latest versions of Ruby on Rails and Tailwind CSS, ensuring the application follows current best practices for performance, maintainability, and responsive design.
Technologies: Ruby on Rails 7, Tailwind CSS, Claude Code, Replit, Heroku
Software Engineer
2026 - 2026
Clarytas
- Built Claire, an AI assistant that combines domain-specific prompts, internal tools, and external APIs, using guardrails and context management to keep responses accurate while guiding users toward generating custom reports.
- Created an admin dashboard for tracking user activity.
- Reworked the credit usage system and added a usage timeline so users can see their consumption history.
- Set up Sentry for error monitoring and supported users by diagnosing and fixing live issues.
Technologies: Python, React, Next.js, ChatGPT API, Claude Code, AI Agents
Ruby on Rails Developer
2023 - 2024
Get Clear Consulting Ltd
- Handled updating the project Docker configuration.
- Updated Rails from version 4.2 to 5.2 and Ruby from 2.4 to 2.5.
- Brought Ansible and Capistrano scripts up-to-date and handled the creation of a staging server on DigitalOcean.
- Implemented new features for customers (e.g., included a new set of icons, new font options from Google Fonts, and advanced settings for fonts used on the site).
- Monitored and fixed bugs after each deployment and brought improvements to the site's functionalities.
Technologies: Ruby on Rails (RoR), JavaScript, HTML, CSS, Less, Capistrano, Ansible, Phusion Passenger, Amazon S3 (AWS S3), Ruby
Full-stack Engineer
2021 - 2023
Cowboy SA
- Developed custom features regarding trip analysis (like personal records), available via API to customer mobile apps and internally via the admin dashboard.
- Created functionalities and maintained an in-house booking platform for on-demand technician appointments.
- Added custom SLA generators for internal reports of technicians' and test riders' availabilities.
- Participated in back-end scaling efforts, moving time-consuming processing to background jobs and researching ways to deal with data streams for each trip.
- Investigated slow queries and improved background database processes like vacuuming and memory bloat.
Technologies: Ruby, Ruby on Rails (RoR), HTML, CSS, JavaScript, PostgreSQL, Agile, Front-end, Back-end, Database Optimization, Sidekiq, Full-stack, Infrastructure, Redis, New Relic, Heroku, Amazon S3 (AWS S3), Amazon Aurora, JSON, Bootstrap, RSpec, Protobuf, Google Places API, Google Calendar API, Typeform.io, Shopify API, GraphQL, Intercom API, Slack API, Firebase, Mapbox, Airtable, Intercom
Front-end Developer
2020 - 2021
Z News Service
- Implemented reusable custom React components for a news-article pipeline submission and management of users and articles.
- Implemented design specifications received via Zeplin into responsive interface components.
- Refactored the page structure and component hierarchy for better maintainability and updates.
Technologies: TypeScript, Next.js, Material Design, APIs, React, Pixel Perfect, Zeplin, Kanban, Jira, Refactoring, Single-page Applications (SPAs), Material UI, JSS, MacOS
Full-stack Developer
2020 - 2021
Stealth Startup
- Helped clients transform their ideas into a solid development plan, with steps, estimates, and recommended technologies.
- Created mockups and user flows for all the features available in the application.
- Developed a website that connects businesses in order to create shared marketing goals. Features included classic and LinkedIn registration, building of profile, discovering other business with filtering options, live chat, and email notifications.
- Implemented design based on Photoshop specifications using Bootstrap and making sure of responsiveness.
Technologies: Ruby, Ruby on Rails (RoR), Unit Testing, Functional Testing, User Interface (UI), User Experience (UX), Web Development, Bootstrap, Heroku, Google Maps, Google Places API, Image Manipulation, RSpec, Communication, CSS3, Jest, MacOS, Full-stack, Infrastructure
Full-stack Developer
2018 - 2020
NearFish App
- Developed a custom Ruby on Rails website and Android application for managing fitness studios.
- Registered and offered support to five fitness studios that used the application for managing their activity.
- Developed custom features based on feedback from fitness studios and helped them use them with their clients.
Technologies: Android Development, Functional Testing, Unit Testing, Scrum, Agile, PostgreSQL, jQuery, React, SCSS, HTML5, JavaScript, Bootstrap, Ruby on Rails (RoR), Kanban, MacOS, Full-stack, Infrastructure
Owner
2017 - 2020
BootstrapBay
- Migrated a custom Bootstrap theme store from a Zend architecture to Ruby on Rails and implemented a new design using Bootstrap.
- Created multiple open-source and premium Bootstrap and React themes distributed through the platform and downloaded by hundreds of users.
- Wrote an in-depth tutorial series about the Bootstrap framework that helps developers get started with it, that was read by thousands of users.
- Developed and maintained business relationships with over 80 theme authors on the BootstrapBay platform and offered support for theme development.
- Offered support for more than 40,000 users registered on the BootstrapBay platform.
Technologies: Ruby, Ruby on Rails (RoR), React, Redux, Bootstrap, WordPress, Agile, User Experience (UX), User Interface (UI), Heroku, Dashboards, Unit Testing, Single-page Applications (SPAs), API Architecture, Architecture, Web Architecture, CSS, CSS3, Jest, MacOS, Full-stack, Infrastructure
Managing Partner
2013 - 2017
Creative Tim
- Developed a platform for uploading, distributing, and selling Bootstrap themes that reached over 500,000 users.
- Designed, developed, and maintained multiple Bootstrap themes and templates downloaded by thousands of developers.
- Offered support for platform users with continuous integration of fixes and improvements for the Bootstrap store.
- Added new features that increased the number of visitors and website conversions, constantly improving the platform's design, speed, and functionality.
- Integrated the Paypal and 2Checkout payment API for handling payments and multiple third-party tools for user tracking and targeted marketing campaigns.
- Developed in-house libraries for email marketing campaigns, product ratings, user support, comments, and notifications systems.
Technologies: Agile, Scrum, Heroku, 2Checkout, JavaScript, SCSS, HTML5, jQuery, Bootstrap, Leadership, Software Architecture, Software Troubleshooting, MySQL, PostgreSQL, Kanban, MacOS, Full-stack, Infrastructure, Ghost, Devise
Project History
VeloVostra
VeloVostra is a free cycling training platform built as a solo project using Ruby on Rails and Tailwind CSS. The entire development process was AI-assisted, with Claude by Anthropic serving as a core partner for coding, research, and content creation. Much of the early work was done on a mobile phone using Replit, and the project continues to evolve with feedback from early users.
Creative Tim
https://www.creative-tim.com/A custom store for distribution of in-house built front-end themes and templates.
Developed the platform and multiple themes with my co-founder. Handled back-end development on Ruby on Rails, integration with 3rd party APIs, and design implementation. Managed a team of developers that created and developed multiple themes and constantly added new features to the platform.
Developed the platform and multiple themes with my co-founder. Handled back-end development on Ruby on Rails, integration with 3rd party APIs, and design implementation. Managed a team of developers that created and developed multiple themes and constantly added new features to the platform.
BootstrapBay
A Bootstrap store that allows authors to sell and market their themes.
Acquired the platform, completed a migration from Zend to Ruby on Rails, and a redesign using Bootstrap. Managed the client and authors' relationships, offering support and advice for better theme creation.
Acquired the platform, completed a migration from Zend to Ruby on Rails, and a redesign using Bootstrap. Managed the client and authors' relationships, offering support and advice for better theme creation.
NearFish
An Android application that works together with a Ruby on Rails server aimed at fitness studios.
Developed a complete dashboard that offered insightful analytics for instructors and an intuitive application for user management. Supported studios using it, managed client expectations, and added newly requested features.
Developed a complete dashboard that offered insightful analytics for instructors and an intuitive application for user management. Supported studios using it, managed client expectations, and added newly requested features.
Lazy Kit React
A React theme with custom components released open-source.
Built on top of Bootstrap 4 and Reactstrap using React Router and SCSS design sheets. Designed, developed, and offered support for developers using the theme.
Built on top of Bootstrap 4 and Reactstrap using React Router and SCSS design sheets. Designed, developed, and offered support for developers using the theme.
Education
2013 - 2015
Master's Degree in Software Engineering
University of Bucharest - Bucharest, Romania
2010 - 2013
Bachelor's Degree in Computer Science
University of Bucharest - Bucharest, Romania
Skills
Libraries/APIs
React, REST APIs, React Redux, React Router, PayPal API, jQuery, Google Maps, Google Places API, Sidekiq, Protobuf, Google Calendar API, Typeform.io, Shopify API, Intercom API, Slack API, Devise, Stripe
Tools
Git, 2Checkout, Zeplin, RSpec, Jira, JSS, Ghost, Capistrano, Ansible, Claude Code
Languages
SCSS, JavaScript, CSS, HTML, Sass, HTML5, SQL, Ruby, Python, C++, TypeScript, CSS3, GraphQL, Less
Frameworks
Ruby on Rails (RoR), Bootstrap, Redux, Next.js, Jest, Material UI, Ruby on Rails 7, Tailwind CSS
Storage
MySQL, PostgreSQL, JSON, Databases, Redis, Amazon S3 (AWS S3), Amazon Aurora
Paradigms
Agile Software Development, Agile, Unit Testing, Functional Testing, REST, Refactoring, Web Architecture, Scrum, Kanban, API Architecture, Database Design
Platforms
MacOS, Heroku, Amazon Web Services (AWS), WordPress, New Relic, Firebase, Mapbox, Phusion Passenger, Replit
Other
Web Development, APIs, Pixel Perfect, Full-stack, Front-end, Back-end, Integration, Full-stack Development, Axios, User Interface (UI), User Experience (UX), Dashboards, Infrastructure, Cloud, Android Development, Image Manipulation, Material Design, Communication, Leadership, Software Architecture, Software Troubleshooting, Single-page Applications (SPAs), Architecture, Computer Science, Algorithms, Graphs, Mathematics, IT Project Management, Data Structures, Multithreading, Database Optimization, Airtable, Artificial Intelligence (AI), AI-generated Code, Vibe Coding, ChatGPT API, AI Agents, Intercom
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