Mohamed is available for hire
Hire MohamedMohamed Khaled
Verified Expert in Engineering
Back-end Developer
Location
Alexandria, Alexandria Governorate, Egypt
Toptal Member Since
January 3, 2022
Mohamed is a back-end engineer who specializes in the design and development of complex architecture and infrastructure. He led a team to deliver a B2B2C shipping system with a customized shipment-flow engine, built a smart in-door navigation service based on NFC-tag [NFC technology], and transferred UI/UX designs to a fully-featured mobile app for iOS and Android devices. Mohamed is proficient with integrations, CMS, and authentication strategies.
Portfolio
Mothership,
TypeScript, JavaScript, TypeORM, Express.js, Architecture...
Hello Iteration,
NestJS, Architecture, Event Sourcing, APIs, Azure, Amazon S3 (AWS S3)...
Descriptive,
Node.js, Modular Design, Architecture, APIs, TypeScript, NestJS, Back-end...
Experience
Availability
Full-time
Preferred Environment
Windows Subsystem for Linux (WSL), Windows, Linux, Visual Studio Code (VS Code), Postman
The most amazing...
...cross-platform application I've designed was a ''supermarket in your pocket'' for bakeries, groceries, fruits, vegetables, and household products.
Work Experience
Senior Software Engineer
2022 - 2022
Mothership,
- Owned the accounting service that manages B2B financial transactions and worked closely with the CTO to plan and design the company's vision for the following quarters.
- Built a complete reusable framework that embraces feature-driven development (FDD), command-query separation (CQS), and separation of concerns.
- Developed a complete business validation layer that throws custom business exceptions with custom status codes.
- Created a Unit of Work design pattern to manage and control database transactions and separated the domain layer from the persistence layer using mappers.
- Participated in the customer platform team, attended daily meetings, and managed new accounting requests through the Asana board and tickets.
- Wrote heavy and complete unit tests for different components. Followed the company's code standards and formatting using prettier rules.
Technologies: TypeScript, JavaScript, TypeORM, Express.js, Architecture, Domain-driven Design (DDD), Feature-driven Development (FDD), REST APIs, API Integration, Microservices, Separation of Concerns (SoC), Jest, Back-end, Unit Testing, REST, Modular Design, RESTful Microservices, Databases, Docker, Amazon Web Services (AWS), Ubuntu, Apache Kafka, Kubernetes, Scalable Architecture, Scalable Application, GitHub, Git, Software Architecture, Scalability, JSON Web Tokens (JWT), Middleware, Message Queues, Integration, Web Development, eCommerce, JSON, Test-driven Development (TDD), Refactoring, API Development
Senior Back-end Engineer
2022 - 2022
Hello Iteration,
- Used the NestJS microservices transport abstraction layer to modularize the application and grant the future scalability plan. Wrote a custom NestJS transport layer for Azure Service Bus to enable publishing and to listen to events.
- Wrote an abstraction and a skeleton for a video-on-demand service composed of smaller microservices.
- Designed and developed an importer microservices that imports data from different data sources.
- Outlined and built a receiver microservice that indexes data, eliminates redundancy, and stores data in Azure Blob Storage.
- Conceived and developed a processor microservice that processes new data and stores updates using an event sourcing technique and creating a snapshot for a fast replay.
Technologies: NestJS, Architecture, Event Sourcing, APIs, Azure, Amazon S3 (AWS S3), Azure Blob Storage API, Azure Service Bus, Microservices, Microservices Architecture, MongoDB, NoSQL, REST APIs, Back-end, Unit Testing, Jest, REST, Modular Design, RESTful Microservices, Databases, IT, Cloud Architecture, Docker, Ubuntu, Apache Kafka, Kubernetes, Scalable Architecture, Scalable Application, ETL, ETL Implementation & Design, GitHub, Git, Software Architecture, Scalability, JSON Web Tokens (JWT), Middleware, Message Queues, Integration, Web Development, JSON, API Development
Back-end Engineer
2022 - 2022
Descriptive,
- Developed a discount module for gift card scenarios, including lookup, redeem, and void options.
- Built a loyalty module, including the integration with Punchh, a third-party loyalty system for managing user rewards and offers.
- Used the NestJS microservices transport abstraction layer to modularise the application, granting the future scalability plan.
- Maintained and fixed reported bugs and issues in an Agile environment.
Technologies: Node.js, Modular Design, Architecture, APIs, TypeScript, NestJS, Back-end, Unit Testing, Jest, TypeORM, REST, RESTful Microservices, Microservices, Databases, IT, Cloud Architecture, Docker, Amazon Web Services (AWS), Ubuntu, Apache Kafka, Kubernetes, Big Data, Leadership, Scalable Architecture, Scalable Application, ETL, ETL Implementation & Design, GitHub, Git, Software Architecture, Scalability, JSON Web Tokens (JWT), Middleware, Message Queues, Authentication, Integration, Web Development, eCommerce, CSS, JSON, Test-driven Development (TDD), Refactoring, API Development
Software Engineer
2021 - 2022
Blackstoneeit
- Implemented and developed, in collaboration with the senior architect, a new architecture framework that uses the latest technologies and concepts from DDD, CQRS, and ES (event sourcing).
- Implemented ESLint custom rules to encourage developers to follow the code standards.
- Wrote MongoDB aggregates and created views to optimize data fetching and overcome (n + 1) query problems.
- Implemented and developed a Jira-service desk integration middleware microservice to handle customer requests.
- Created a document analyzer micro-service to extract data from PDF documents based on the client's needs to automate uploading the files and extracting the data manually.
- Maintained and developed different microservices based on new feature requests or reported bugs.
Technologies: Node.js, TypeScript, Loopback, Microservices, RabbitMQ, Kanban, MongoDB, Jira, Jira REST API, Socket.IO, Domain-driven Design (DDD), ESLint, JavaScript 6, RESTful Services, APIs, REST APIs, ServiceDesk, Infrastructure, API Integration, Architecture, Web Architecture, Back-end Architecture, Back-end Development, Microservices Architecture, RESTful Microservices, NoSQL, WebSockets, Back-end, Unit Testing, Jest, TypeORM, REST, Modular Design, Databases, IT, Ubuntu, Apache Kafka, Big Data, Leadership, Scalable Architecture, Scalable Application, ETL, ETL Implementation & Design, Software Architecture, Scalability, JSON Web Tokens (JWT), Middleware, Message Queues, Authentication, Integration, Web Development, JSON, Test-driven Development (TDD), Refactoring, API Development
Full-stack Mobile Developer
2020 - 2021
Arabi Market
- Implemented and developed RESTful APIs for the mobile app and the CMS.
- Integrated third-parties such as payment gateways (Stripe and PayPal), Google Maps (Places), and AWS SNS for sending SMS notifications.
- Transferred the UI/UX design to a fully featured mobile app using the Expo framework for both iOS and Android devices.
Technologies: React Native, Node.js, Express.js, Sequelize, PayPal API, Stripe API, Google Maps API, Expo.io, Google Places API, MySQL, AWS Simple Notification Service (SNS), JavaScript 6, RESTful Services, APIs, HTML, SQL, REST APIs, Infrastructure, API Integration, Architecture, Web Architecture, Back-end Architecture, Back-end Development, Entity–Boundary–Interactor (EBI), React, PostgreSQL, Back-end, REST, Modular Design, Databases, IT, Cloud Architecture, Amazon Web Services (AWS), Full-stack, Ubuntu, Leadership, Scalable Application, GitHub, Git, Software Architecture, JSON Web Tokens (JWT), Authentication, Integration, Web Development, eCommerce, CSS, Progressive Web Applications (PWA), JSON, Refactoring, API Development
Software Engineer
2019 - 2021
Alexapps
- Led a team of developers to build and deliver a B2B shipping system with a customized shipment-flow engine with custom states and transitions to track the shipment status.
- Built a smart in-door navigation service based on NFC-tag (NFC technology) to find the shortest path to the required destination.
- Created cross-platform desktop applications using the Electron framework.
- Maintained and fixed bugs and issues for different web apps.
- Developed a customizable and reusable administrative panel and front-end components that saved time.
Technologies: Node.js, TypeScript, Sequelize, Mongoose, MySQL, MongoDB, SQLite, Electron, JavaScript 6, RESTful Services, APIs, Vuex, HTML, Vuetify, NestJS, SQL, REST APIs, Infrastructure, API Integration, Architecture, Web Architecture, Back-end Architecture, Back-end Development, Entity–Boundary–Interactor (EBI), Vue, PostgreSQL, NoSQL, Back-end, TypeORM, REST, Modular Design, Databases, IT, Cloud Architecture, Full-stack, Ubuntu, Leadership, Scalable Architecture, Git, JSON Web Tokens (JWT), Middleware, Authentication, Integration, Web Development, eCommerce, CSS, Progressive Web Applications (PWA), JSON, Test-driven Development (TDD), Refactoring, API Development
Back-end Developer
2018 - 2019
Q e-markets
- Developed new features in an agile team and maintained and fixed reported bugs and issues.
- Added a new authentication strategy using Google OAuth 2.0 APIs.
- Ensured authorization of resolvers by creating policies and permissions and parsing GraphQL nodes based on request permissions.
Technologies: Node.js, TypeScript, Express.js, GraphQL, MySQL, Sequelize, JavaScript 6, RESTful Services, APIs, SQL, REST APIs, API Integration, Architecture, Web Architecture, Back-end Architecture, Back-end Development, PostgreSQL, Back-end, REST, Modular Design, Databases, Full-stack, Ubuntu, JSON Web Tokens (JWT), Middleware, Web Development, eCommerce, JSON, API Development
Experience
TDRA Management Services
https://tdra.gov.ae/TDRA ensures excellent telecommunication services by implementing relevant policy and regulatory frameworks, developing human resources, and promoting research and development. As a software engineer at TDRA, I designed, implemented, and developed different services and management systems. I also developed highly effective frameworks that focus on the separation of domain development and infrastructure concerns.
Puttshack
https://www.puttshack.com/A Nest.js-based booking application for mini-golf games. As a back-end engineer, I was responsible for creating modules and integrating third-party gift card provider's APIs such as FocusPOS and UK GiftPro APIs. I also Integrated a loyalty system such Punchh for managing user's rewards and offers.
Waselleeom Shipping system
http://waselleeom.com/A B2B shipping system that accepts shipping orders from different vendors to be delivered to customers with a tracking system. As a team leader, I lead a team of two back-end engineers and two front-end engineers in designing and developing the company’s features.
Arabi Market
A cross-platform app designed with a mindset of "a supermarket in your pocket" for bakeries, groceries, fruits, vegetables, and household products. I was a full-stack developer who designed and developed RESTful APIs for both the app, the CMS, and the mobile app using the latest framework, Facebook's Expo.io, ensuring smooth customer interactions.
Skills
Languages
TypeScript, JavaScript, JavaScript 6, GraphQL, SQL, HTML, CSS
Frameworks
Loopback, Express.js, Vuetify, JSON Web Tokens (JWT), React Native, Electron, NestJS, Jest
Libraries/APIs
Node.js, REST APIs, API Development, Jira REST API, Socket.IO, PayPal API, Stripe API, Google Maps API, Google Places API, React, Vue, Vuex, Azure Blob Storage API
Tools
Postman, Sequelize, Expo.io, Mongoose, GitHub, Git, Jira, ServiceDesk, RabbitMQ, AWS Simple Notification Service (SNS)
Paradigms
Microservices, Web Architecture, Back-end Architecture, Modular Design, Scalable Application, Refactoring, Unit Testing, ETL, ETL Implementation & Design, Test-driven Development (TDD), Microservices Architecture, Kanban, REST, Event Sourcing
Platforms
Visual Studio Code (VS Code), Linux, Ubuntu, Apache Kafka, Windows, Azure, Docker, Amazon Web Services (AWS), Kubernetes
Storage
Databases, JSON, MongoDB, PostgreSQL, MySQL, SQLite, NoSQL, Amazon S3 (AWS S3)
Other
Algorithms, Data Structures, Rich Internet Applications, RESTful Microservices, API Integration, APIs, RESTful Services, Architecture, Back-end Development, TypeORM, Feature-driven Development (FDD), Back-end, Scalable Architecture, Software Architecture, Scalability, Middleware, Authentication, Integration, Web Development, eCommerce, Windows Subsystem for Linux (WSL), OOP Designs, Distributed Systems, Entity–Boundary–Interactor (EBI), Infrastructure, Full-stack, Leadership, Message Queues, Machine Learning, Domain-driven Design (DDD), ESLint, Azure Service Bus, Separation of Concerns (SoC), WebSockets, IT, Cloud Architecture, Big Data, Progressive Web Applications (PWA)
Education
2015 - 2020
Bachelor's Degree in Computer Science
Helwan University - Helwan, Cairo, Egypt