Ovidiu is available for hire
Hire OvidiuOvidiu Deliu
Verified Expert in Engineering
Front-end Developer
Cluj-Napoca, Cluj County, Romania
Toptal member since March 6, 2024
Bio
Ovidiu is a front-end developer with 5+ years of React and React Native experience with startups and leaders in edtech, IoT, blockchain, delivery, and eCommerce. He integrates Redux, RTK, Redux-Saga, Redux Thunk, and Jest to enhance interface design with Material UI and styled-components and employs Storybook for development efficiency. Ovidiu's work includes an app that ranks steadily in Google Play and App Store's top 10 and a web and mobile app that grew valuations from €0 to €1.6 million.
Portfolio
IBM
React, React Native, TypeScript, JavaScript, Next.js, React Server Components...
BlackTree Software
React Native, RTK Query, Redux, Redux Thunk, REST, WebSockets...
RebelDot
React, Redux, Redux Thunk, Redux Toolkit, React Query, Axios, Figma, Storybook...
Experience
- JavaScript - 5 years
- Git - 5 years
- React - 5 years
- TypeScript - 5 years
- React Native - 5 years
- Redux - 5 years
- Firebase - 4 years
- Jest - 3 years
Work Experience
Senior React & React Native Engineer
2024 - 2026
IBM
- Built a Next.js 15 and React 19 web app for an enterprise EV-charging platform (App Router and React Server Components), covering real-time charging sessions and unauthenticated guest checkout.
- Developed a React Native micro-frontend platform of ~14 independently versioned feature MFEs in a host shell, with a custom SDK/CLI standardizing codegen, lint, test, and native builds.
- Engineered a typed GraphQL data layer (Apollo Client and Codegen) with a composable link chain (auth, request-abort, timing, and X-Ray tracing) and end-to-end type safety from a federated schema.
- Delivered region-aware payments and i18n: 3DS/Cardinal drop-in with pre-auth and timeout recovery, a 5-locale FormatJS pipeline, and country-scoped feature flags.
- Contributed to a cross-platform design system rendering on native and web (react-native-web), shared by the platform's mobile and web apps.
Technologies: React, React Native, TypeScript, JavaScript, Next.js, React Server Components, Git, Bitbucket, Azure DevOps, GraphQL, Apollo Client, REST APIs, Microfrontends, Design Systems, Jest, React Testing Library, Playwright, Storybook, i18n, i18next, 3D Secure, AWS IoT, Node.js
Senior Front-end Platform Engineer (React Native, Expo, and React)
2024 - 2026
BlackTree Software
- Consolidated four iGaming brands into one Expo, React Native, and TypeScript monorepo with per-brand configuration and a single build and release pipeline for iOS and Android.
- Built and shipped two full-native React Native apps from scratch as the sole mobile engineer, reaching around 99% crash-free sessions and a 4.7 star rating across 1,300+ reviews.
- Re-architected the two standalone React Native apps into a hybrid model: a native shell hosting each brand's web platform in a WebView, with native features exposed through a secure bridge.
- Built a secure WebView-to-native bridge with a typed message protocol, origin gating, and payload redaction (types only, never values).
- Established around 3,700 automated tests in the monorepo, with mutation testing of critical rules and per-release device validation logs.
- Designed a multi-agent AI workflow (orchestrator, implementer, and reviewer) with a mutation-tested safety guard of 500+ test cases, shipping dozens of reviewed PRs under a human merge gate.
Technologies: React Native, RTK Query, Redux, Redux Thunk, REST, WebSockets, Server Sent Events (SSE), Axios, React Native Reanimated, Figma, React Navigation, React Hook Form, React Hooks, Redux Persist, TypeScript, Authorization, User Experience (UX), User Interface (UI), Push Notifications, Expo, React, JavaScript, iOS, Android, Kotlin, WebView, Firebase, AppsFlyer, Design Systems
React Developer
2024 - 2024
RebelDot
- Reduced the time needed to perform changes on the company allocation data by 5x since the web software solution's first deployment. The web app significantly optimized multiple processes that were previously handled by delivery managers.
- Improved new hiring logistic processing time by 250% by integrating two popular user management tools from the international market into the app.
- Enhanced transparency and reporting time to outsourced clients by 150% by implementing an automated user and project report generation system.
- Managed a team of two junior developers, offering technical guidance on the project.
- Assisted and helped in making business decisions regarding software integrations that would best fit the product.
- Researched and tested multiple integration solutions for UI component libraries that would best fit the Figma designs.
- Held sprint retrospective presentations regarding the project's current state and the latest implementations and fixes.
Technologies: React, Redux, Redux Thunk, Redux Toolkit, React Query, Axios, Figma, Storybook, Material UI, Jest, CSS, Microsoft Authentication Library (MSAL), REST APIs, Firebase, JavaScript, Asynchronous Programming, HTML5, Responsive Design, Front-end Development, Cross-browser Compatibility, CSS3, TypeScript, CI/CD Pipelines, React Hook Form, HTML, Front-end, Visualization, App UI, API Integration, Authorization, User Experience (UX), User Interface (UI), Push Notifications
React and React Native Developer
2023 - 2024
RebelDot
- Reduced infrastructure costs by 40% by developing a web admin platform and a mobile cross-platform app that relieved the client of paying multiple software subscriptions—totaling 40% of their budget.
- Boosted client delivery productivity by 25% by developing two features that ensured easier delivery flows and an engaging experience for the delivery drivers.
- Increased app robustness and scalability by raising the test coverage from 5% to 92%, adding multiple unit and snapshot tests and stories.
- Guided a small team of two junior developers on bot React and React Native technologies.
Technologies: React, React Native, Git, Bitbucket, Redux Toolkit, React Query, Axios, Vite, Jest, i18n, Lodash, ESLint, Material UI, Lottie, Algorithms, Storybook, TypeScript, Redux, REST APIs, JavaScript, Asynchronous Programming, HTML5, Responsive Design, Front-end Development, Cross-browser Compatibility, CSS3, CI/CD Pipelines, React Hook Form, HTML, CSS, Front-end, App UI, API Integration, Authorization, User Experience (UX), User Interface (UI), Push Notifications
React Native Developer
2022 - 2023
RebelDot
- Improved app maintainability by 90% by developing a mobile super app that merged the functionalities of three different platforms from the same client.
- Doubled the app usage time for active users by implementing various gamification features and push notifications.
- Increased user retention by 20% by enabling users to link and perform operations on their wallets from other blockchains and platforms.
- Implemented multiple proprietary blockchain integration features such as crypto staking and NFTs.
- Held sprint presentations every two weeks for the implemented features and bug fixes.
Technologies: React Native, GitHub, Fastlane, TypeScript, Redux, Redux Thunk, Jest, Application State Management, JSX, Android Studio, Xcode, Socket.IO, REST, Storybook, Git, REST APIs, JavaScript, Asynchronous Programming, Responsive Design, Front-end Development, CSS3, CI/CD Pipelines, Front-end, App UI, API Integration, Android, iOS, Authorization, User Experience (UX), User Interface (UI), Push Notifications
React and React Native Developer
2021 - 2022
RebelDot
- Grew valuation by 50% after a year by developing a mobile IoT application and an admin web platform for managing street and private parking lots across 10+ cities in Romania and Italy.
- Increased revenue by 30% by fully developing and launching an EV charging module that enabled users to charge their electric vehicles at designated charging stations.
- Boosted user retention from 15% to 30% by integrating the reliable payment service provided by Stripe.
- Refactored obsolete Redux-Saga flows from class to function components and hooks, significantly improving app performance.
- Improved app robustness and delivery time by integrating Jest and unit tests on web and mobile apps, reducing QA efforts.
- Integrated the client's proprietary design system and refactored the web app's UI.
Technologies: React, React Native, Redux, Redux-Saga, Firebase, GitLab, Continuous Integration (CI), Continuous Delivery (CD), Jira, Scrum, Monorepos, Android Studio, Xcode, Jest, Axios, REST APIs, JavaScript, Asynchronous Programming, GraphQL, HTML5, Responsive Design, Front-end Development, Cross-browser Compatibility, CSS3, TypeScript, CI/CD Pipelines, HTML, CSS, Front-end, Visualization, App UI, API Integration, Android, iOS, Authorization, User Experience (UX), User Interface (UI), Push Notifications, Expo
React and React Native Developer
2019 - 2021
Izibac
- Grew company valuation from €0 to €1.6 million in one year after developing the web admin platform and mobile app.
- Ranked number one in Romanian educational apps in the 1st month of launching.
- Empowered 10,000+ monthly active users in the last 12 active months.
- Refactored the whole app with TypeScript after initially developing it with JavaScript.
- Integrated and implemented Storybook for the web and mobile app's UI components.
- Fixed multiple critical issues reported by users in the production environment.
Technologies: React, React Native, Redux, TypeScript, Storybook, Material UI, Bitbucket, Redux Thunk, REST APIs, Firebase, Android Studio, Xcode, Webpack, JavaScript, Asynchronous Programming, HTML5, Responsive Design, Front-end Development, Cross-browser Compatibility, CSS3, HTML, CSS, Front-end, App UI, API Integration, Authorization, User Experience (UX), User Interface (UI), Push Notifications, Expo
Java Developer
2018 - 2019
Ceragon Networks
- Developed two full-stack features that were launched into the production version. The features included changes in all areas, from the client app and server codebase to the database.
- Fixed multiple critical issues reported by the QA team and client representatives.
- Refactored obsolete code by applying updated methodologies, design patterns, and technologies.
- Assisted in brainstorming, planning, estimating, and reviewing future objectives and tasks according to the latest agile-scrum processes.
- Held three client presentations on the features and areas of ownership.
Technologies: Java, Spring, Hibernate, Kanban, Subversion (SVN), PostgreSQL, Elasticsearch, Java EE (Jakarta EE), REST APIs, Asynchronous Programming, Front-end Development, HTML, Front-end, Visualization, App UI, API Integration, Authorization
Project History
Developer and Training Program Performance Tracker
A Java and Apache Ant full-stack application integrating multiple static-code analyzers that support C, C++, Java, JavaScript, TypeScript, Python, and C# programming languages.
The app assesses a developer's code-writing patterns and the impact training programs have on the developer's performance and problem-solving abilities.
The app assesses a developer's code-writing patterns and the impact training programs have on the developer's performance and problem-solving abilities.
Microfrontends Demo App
A small micro-frontends app for demonstrating modularity, scalability, and performance improvements of a web app using a micro-frontends architectural pattern.
The ecosystem comprises a main app that renders the micro-frontend solutions at runtime and four micro-frontend applications built separately, each with its own functionality and design.
The ecosystem comprises a main app that renders the micro-frontend solutions at runtime and four micro-frontend applications built separately, each with its own functionality and design.
Education
2014 - 2018
Bachelor's Degree in Computer Science
Politehnica University of Bucharest - Bucharest, Romania
Certifications
FEBRUARY 2020 - PRESENT
Legacy JavaScript Algorithms and Data Structures
freeCodeCamp
JANUARY 2020 - PRESENT
Responsive Web Design
freeCodeCamp
JULY 2018 - PRESENT
WordPress Development with Bootstrap: The Complete Course
Udemy
JUNE 2018 - PRESENT
JSP, Servlets and JDBC for Beginners: Build a Database App
Udemy
Skills
Libraries/APIs
React, REST APIs, Redux-Saga, React Query, Lodash, React Hook Form, JDBC, Socket.IO, Microsoft Authentication Library (MSAL), React Navigation, Redux Persist, Apollo Client, React Testing Library, Playwright, Node.js
Tools
Git, Redux Toolkit, Slack, Google Meet, pgAdmin, Bitbucket, Redux Thunk, GitLab, GitHub, Fastlane, Expo, Zoom, Postman, Subversion (SVN), Android Studio, Xcode, Webpack, JSPM, Servlet, Jira, JSX, Figma, Apache Ant, RTK Query, WebView
Languages
TypeScript, JavaScript, HTML, CSS, HTML5, CSS3, Java, PHP, SQL, GraphQL, Kotlin
Frameworks
React Native, Redux, Material UI, Spring, Hibernate, Bootstrap, Jest, Jakarta Server Pages (JSP), Next.js, i18next
Paradigms
Mobile Development, Scrum, Asynchronous Programming, Continuous Integration (CI), REST, Kanban, Continuous Delivery (CD), Microfrontends, Azure DevOps
Platforms
Visual Studio Code (VS Code), Firebase, MacOS, Java EE (Jakarta EE), WordPress, Android, iOS, AppsFlyer, AWS IoT
Storage
PostgreSQL, Elasticsearch
Other
Web Development, Algorithms, Axios, i18n, Lottie, Responsive Design, Front-end Development, Cross-browser Compatibility, Front-end, App UI, API Integration, Authorization, User Experience (UX), User Interface (UI), Push Notifications, Storybook, ESLint, CI/CD Pipelines, Visualization, Full-stack Development, Monorepos, Application State Management, Vite, Compilers, Styled-components, WebSockets, Server Sent Events (SSE), React Native Reanimated, React Hooks, Design Systems, React Server Components, 3D Secure
Collaboration That Works
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
1
Share your needs
Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2
Choose your talent
Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3
Start your risk-free talent trial
Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.
Top talent is in high demand.
Start hiring