Mohamed is available for hire
Hire MohamedMohamed Oussama Khezour
Verified Expert in Engineering
Full-stack Engineer and Developer
Sliema, Malta
Toptal member since August 29, 2023
Bio
Oussama is a full-stack engineer specializing in React Native. With over seven years in the field, he has contributed to various projects that have solved real-world challenges. He has also developed critical internal tools that have enhanced organizational efficiency. Proficient in both front- and back-end technologies, Oussama's commitment to high-quality coding and best practices positions him as a dependable asset in any software development endeavor.
Portfolio
PepsiCo Global - Main
React Native, React, SwiftUI, Kotlin, Fastlane, GraphQL, Apollo Client, iOS...
Nivoda
React Native, GraphQL, iOS, Swift, Android, iOS Native Libraries, iOS SDK...
CloudWind
TypeScript, React, React Native, AWS Lambda, API Gateways, Amazon DynamoDB...
Experience
- SQL - 2 years
- TypeScript - 2 years
- React - 2 years
- JavaScript - 2 years
- React Native - 2 years
- AWS Lambda - 1 year
- Databases - 1 year
- Node.js - 1 year
Preferred Environment
React Native, TypeScript, React, Node.js, Amazon Web Services (AWS), SQL, Swift, Kotlin/Native, SwiftUI, Expo
The most amazing...
...thing I've done was serving as a key contributor to Nivoda's mobile B2B app, which resulted in a threefold increase in the user base within a year.
Work Experience
Senior Full-stack Developer
2023 - PRESENT
PepsiCo Global - Main
- Migrated Gatorade GX releases to GitHub Actions (iOS and Android) with multi-environment pipelines and automated store submissions; cut manual steps and improved QA workflow.
- Contributed critical features to the GX app across Android and iOS, including user-facing flows and platform integrations.
- Delivered a full-fledged internal eCommerce demo in less than two weeks (auth, catalog, checkout, orders) to validate product use cases and stakeholder feedback.
- Implemented platform-specific features in Swift and Kotlin for smart bottle communication handling and sweat patch scanning logic; contributed to keeping the React Native version up to date.
- Shipped support for 10 LATAM countries, with dynamic feature flags and an abstraction for handling units across the imperial and metric systems.
- Supported migration efforts from Xamarin to React Native on a SodaStream app to streamline development and improve maintainability.
Technologies: React Native, React, SwiftUI, Kotlin, Fastlane, GraphQL, Apollo Client, iOS, Swift, HealthKit, AI Tools, Android, iOS Native Libraries, iOS SDK, Speech Recognition, CI/CD Pipelines, App Store, Authentication, REST APIs
React Native Engineer
2022 - 2023
Nivoda
- Delivered mobile and web feature parity, contributing to a 3x increase in active users in one year.
- Re-engineered the checkout flow from the ground up and introduced Stripe payments and multiple shipping options, resulting in positive customer feedback and enhanced user experience.
- Standardized UI elements by developing a reusable, type-safe component library, reducing styling code by 40%.
- Instituted best coding practices, including TypeScript migration and ESLint rule enforcement, elevating code quality and long-term maintainability.
- Achieved a 65% reduction in iOS app size and a 40% reduction in Android app size through optimization techniques.
- Led the version 2 product release, incorporated new features and a complete redesign, and expanded product offerings to include Gemstones.
- Automated app store submissions and updates using CI/CD pipelines and Expo Application Services (EAS), reducing manual release efforts by 60%.
- Maintained and updated the customer-facing Loupe360 iPad app, ensuring a high-quality user experience and functionality.
- Mentored new engineers in code reviews and best practices, improving team productivity and code quality.
Technologies: React Native, GraphQL, iOS, Swift, Android, iOS Native Libraries, iOS SDK, Speech Recognition, Voice Recognition, Google Play Store, Push Notifications, App Store, Authentication, REST APIs
Full-stack Engineer
2021 - 2022
CloudWind
- Played a key role in the front- and back-end development of Houmti, a social media app, contributing to a 30% increase in user engagement over six months.
- Used AWS technologies like Lambda, DynamoDB, and API Gateway to create a serverless back end and reduced operational costs by 40%.
- Implemented high-impact features such as chat, polls, profile editing, and geolocation, leading to a 15% increase in daily active users.
- Streamlined code management processes by updating and maintaining internal repositories and documentation.
- Offered technical support to teammates, aiding in a 25% reduction in bug-related delays in project timelines.
Technologies: TypeScript, React, React Native, AWS Lambda, API Gateways, Amazon DynamoDB, Amazon Cognito, Amazon S3 (AWS S3), Amazon EC2, Node.js, SQL, JavaScript, Next.js, Authentication
Software Engineer
2019 - 2021
CERIST
- Developed an advanced log file analysis platform for web applications using Python, Numpy, and TensorFlow to help administrators detect and prevent potential vulnerabilities and cyber attacks using custom-built AI models.
- Created an advanced data visualization dashboard using React, materialUI to provide a rich and efficient interpretation of the analysis results.
- Integrated the log file analysis platform with Kibana (ELK) to enhance the data visualization and monitoring capabilities.
- Developed an online recruitment web dashboard that allows candidates to submit applications for various positions and recruiters to manage the applications and publish job postings on the website.
Technologies: Java, JEE, HTML, CSS, Python 3, JavaScript, React, MariaDB, Relational Databases, TensorFlow, UML
Experience
Gatorade Gx
https://apps.apple.com/us/app/gatorade-gx-sports-science/id1525554148Worked on the next-gen Gx app by Gatorade, which delivers personalized training, nutrition, and hydration plans for athletes based on their goals and daily activity. Users can choose guided programs tailored to specific sports like basketball or soccer, with dynamic recommendations that adjust based on Apple Health data and user preferences.
Integrated Gatorade’s Smart Gx Bottle using a custom SDK that communicates via Bluetooth. This feature allows the app to track hydration in real time and give users personalized fluid intake recommendations throughout the day.
We also worked with third-party SDK providers to integrate sweat patch scanning and detection. These patches analyze sweat composition to provide detailed hydration insights, and we added support for scanning multiple patches at once—especially useful for teams.
Integrated Gatorade’s Smart Gx Bottle using a custom SDK that communicates via Bluetooth. This feature allows the app to track hydration in real time and give users personalized fluid intake recommendations throughout the day.
We also worked with third-party SDK providers to integrate sweat patch scanning and detection. These patches analyze sweat composition to provide detailed hydration insights, and we added support for scanning multiple patches at once—especially useful for teams.
Nivoda B2B App
https://apps.apple.com/in/app/nivoda/id1492499222Worked on the Nivoda mobile app, bringing the full diamond buying and selling experience to mobile. The goal was to align the app’s features with the web platform so users could search, filter, and purchase diamonds just as easily on the go. I led the v2 release, which included a complete redesign, added gemstone support, and introduced key features like advanced search filters, order management, and real-time notifications for buyers and sellers.
Rebuilt the entire checkout flow from scratch, integrating Stripe and multiple shipping options for a smoother purchasing experience. I also helped integrate features like information requests (eye-clean, BGM, media) and a rich order history view.
To improve performance and maintainability, I migrated the codebase to TypeScript, enforced ESLint rules, and built a reusable component system that significantly reduced UI duplication. Through various optimization techniques, I managed to cut the app size by 65% on iOS and 40% on Android.
Set up CI/CD pipelines using Expo EAS to automate app submissions and updates, saving hours of manual work each release.
Rebuilt the entire checkout flow from scratch, integrating Stripe and multiple shipping options for a smoother purchasing experience. I also helped integrate features like information requests (eye-clean, BGM, media) and a rich order history view.
To improve performance and maintainability, I migrated the codebase to TypeScript, enforced ESLint rules, and built a reusable component system that significantly reduced UI duplication. Through various optimization techniques, I managed to cut the app size by 65% on iOS and 40% on Android.
Set up CI/CD pipelines using Expo EAS to automate app submissions and updates, saving hours of manual work each release.
Tayssir
An inventory management application to assist small business owners in managing their daily operations, including products, sales, purchases, transactions, and employee management.
I developed and implemented various features to enhance productivity, including detailed reports, user permission controls, alerts for inventory shortages and product expirations, and more.
I developed and implemented various features to enhance productivity, including detailed reports, user permission controls, alerts for inventory shortages and product expirations, and more.
Education
2019 - 2021
Master's Degree in Artificial Intelligence
University of Science And Technology Houari Boumediene (USTHB) - Algiers, Algiera
2016 - 2019
Bachelor's Degree in Computer Science
University of Science And Technology Houari Boumediene (USTHB) - Algiers, Algiera
Skills
Libraries/APIs
Node.js, HealthKit, iOS Native Libraries, REST APIs, React, TensorFlow, Apollo Client, Stripe
Tools
Claude, Sequelize, Amazon Cognito, Expo, Fastlane
Languages
Swift, TypeScript, SQL, Python 3, Java, JavaScript, GraphQL, Kotlin, HTML, CSS, UML
Frameworks
React Native, iOS SDK, Material UI, Express.js, SwiftUI, Next.js
Platforms
iOS, AWS Lambda, Android, Amazon EC2, Amazon Web Services (AWS), WatchOS, JEE, Firebase
Paradigms
Serverless Architecture, Compiler Design, Object-oriented Programming (OOP)
Storage
Databases, PostgreSQL, Amazon DynamoDB, Amazon S3 (AWS S3), MariaDB, Relational Databases
Other
AI Tools, CI/CD Pipelines, App Store, Push Notifications, Google Play Store, Authentication, B Oracle, Heuristics, Neural Networks, Deep Neural Networks (DNNs), Deep Reinforcement Learning, Algorithms, System Design, Web Development, API Gateways, Kotlin/Native, Speech Recognition, Voice Recognition
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