Rei is available for hire

Rei Bengu

Verified Expert in Engineering

Software Developer

Tirana, Tirana County, Albania

Toptal member since September 1, 2016

Expertise

Full-stack Back-end Developers Front-end Fintech Development Data Engineering HTML5 CSS JavaScript Ruby on Rails SQL MySQL jQuery

Bio

Rei is a senior full-stack developer with over a decade of experience creating web applications. He loves participating in the open-source community by adopting or contributing to different projects. Rei is a perfectionist driven by a deep curiosity about literally everything; he enjoys learning, problem-solving, taking on new challenges, and bringing value to clients via web solutions and high-performance applications built with JavaScript, Go, and modern frameworks.

Portfolio

Klarna

Node.js, TypeScript, React, Mobile Banking, Online Banking, Payment APIs...

Toptal Clients

CSS3, HTML5, Vue, Laravel, MySQL, PHP, Ruby on Rails (RoR), React, Express.js...

Balkatek

CSS3, HTML5, Vue, AngularJS, Laravel, MySQL, PHP, JavaScript, PostgreSQL...

Experience

Ruby on Rails (RoR) - 10 years
JavaScript - 10 years
React - 7 years
Vue - 7 years
Express.js - 7 years
Laravel - 6 years
TypeScript - 5 years
Next.js - 4 years

Availability

Part-time

Preferred Environment

Git, Visual Studio Code (VS Code), Linux, MacOS, DataGrip

The most amazing...

...thing I've created is an electronic game using VHDL.

Work Experience

Senior Software Engineer

2020 - 2024

Klarna

Created and integrated the fee service and its corresponding front-end components, handling exceptionally high traffic and managing fee calculations for cards based on multiple factors including region, merchant, refunds, and card amount.
Implemented new features and fixes on existing services, such as couponing and store-configs while also developing their corresponding interfaces for mobile, web, and Chrome extension.
Modernized, refactored, and migrated services to Node.js and front-end apps to React to improve maintainability and performance following acquisition of a complementary business.
Developed end-to-end admin data and analytics solutions, including deployment, reporting, and evaluation.

Technologies: Node.js, TypeScript, React, Mobile Banking, Online Banking, Payment APIs, Digital Payments, Fintech, Card Payments, Docker, OpenAI GPT-4 API, OpenAI GPT-3 API, REST APIs, Full-stack, API Development, Kubernetes, Nuxt.js, API Integration, Microservices, gRPC, Distributed Systems, Back-end Development, Redis, Front-end Development, Front-end, GraphQL, REST, ECMAScript (ES6), SDKs, Architecture, Jest, Authentication, JSON, Single Sign-on (SSO), Payment Gateways, Data Engineering, Business Intelligence (BI), Machine Learning, BigQuery, Amazon EC2, Amazon DynamoDB, Full-stack Development, Prisma, Artificial Intelligence (AI), Chrome Extensions, AI Chatbots, Chatbots, Jenkins, Kibana, Software Architecture, System Design, Apache Kafka, Databases

Software Engineer

2016 - 2021

Toptal Clients

Designed and implemented a user-friendly application to manage pension funds featuring automated calculations, portfolio tracking, and intuitive dashboards.
Worked with debt collection software by rebuilding, testing, and maintaining parts of legacy software, including refactoring components using modern front-end and back-end frameworks.
Led the development of a social media platform for beauty influencers similar to Instagram while collaborating on a comprehensive component library that adhered to the client's established design system.
Worked with the biggest affiliate software for Skrill, NETELLER, and ecoPayz to develop, refactor, and migrate business-critical services while building new React and React Native mobile apps to enhance user experience.

Technologies: CSS3, HTML5, Vue, Laravel, MySQL, PHP, Ruby on Rails (RoR), React, Express.js, JavaScript, Node.js, APIs, Ruby, Design Principles, NestJS, TypeORM, PostgreSQL, Docker, MongoDB, REST APIs, Full-stack, API Development, API Integration, Microservices, Distributed Systems, Back-end Development, Redis, Front-end Development, Front-end, REST, ECMAScript (ES6), SDKs, Architecture, Jest, Authentication, JSON, Tailwind CSS, Full-stack Development, Stripe Payments, Databases

Software Engineer

2015 - 2020

Balkatek

Developed an online learning platform with web and mobile clients, 1-on-1 and group lessons, and interactive study plans with tutor reviews and assignments.
Modernized an old legacy HR management application, refactoring and migrating it to modern front-end and back-end frameworks.
Developed customer support and ticketing software integrated with Twilio for call routing, email integration, online chat, and call recording.
Created connection and configuration software for access control devices.
Built management SaaS software to manage distributors, customers, packages, add-ons, invoices, licensing, and email/invoice templates.

Technologies: CSS3, HTML5, Vue, AngularJS, Laravel, MySQL, PHP, JavaScript, PostgreSQL, Ruby on Rails (RoR), PostgreSQL 9, APIs, Ruby, Design Principles, REST APIs, Full-stack, API Development, API Integration, Back-end Development, Redis, Front-end Development, Front-end, REST, ECMAScript (ES6), Architecture, Jest, Authentication, JSON, Full-stack Development, Databases

Software Engineer

2018 - 2019

Luxasia (Enterprise Toptal Client)

Built and maintained a social media platform for beauty influencers similar to Instagram.
Collaborated with business team to design, develop prototypes and write tools; also extracted insights from these data activities to inform business decisions.
Worked closely with report developers and business process owners to empower data-backed decision-making.

Technologies: CSS3, HTML5, JavaScript, Elasticsearch, Laravel, MySQL, PHP, APIs, Design Principles, PostgreSQL, REST APIs, Full-stack, API Development, API Integration, Back-end Development, Redis, Front-end Development, Front-end, REST, ECMAScript (ES6), Architecture, Jest, Authentication, JSON, Full-stack Development, Databases

Software Developer

2013 - 2015

CodeCanyon

Created a booking and appointment system with user-defined services and providers, notifications via SMS/email, and client/admin interfaces.
Developed a sales and inventory management system for factories with smart product composition and pricing/reporting based on ingredients.
Built a social platform for anonymous confession with comments, likes, and community moderation using Yii.

Technologies: CSS3, HTML5, JavaScript, Laravel, MySQL, PHP, APIs, Design Principles, PostgreSQL, REST APIs, Full-stack, API Development, API Integration, Back-end Development, Redis, Front-end Development, Front-end, Architecture, Authentication, JSON, Full-stack Development, Databases

Experience

Freyja Community

Connect with fellow enthusiasts who share your passion for beauty and dive into empowering conversations. Browse through beauty looks, share your own creation, discover new tricks, and learn from experts.

iLingo

The world's only cloud-based language learning platform with a personalized program and live tutors. Proven methodology, technology, and live lessons are delivered in real-time and personalized for each student's and employee's unique learning needs.

Laravel Auto-validation

https://github.com/reibengu/laravel-auto-validation

Auto-validation is an open-source package for Laravel that will allow users to remove all manual validations from the controllers by extracting the validation rules to an external config file that matches the controller name and method.

Traefik Docker Configuration

https://github.com/reibengu/traefik-docker-wordpress

This example project demonstrates how to configure Traefik with Docker to run a WordPress website, MySQL database, and Adminer for database management. It also includes the setup of local SSL certificates using the mkcert library for secure communication.

TypeScript Express Starter

Express boilerplate, backed by TypeScript and Klarna's endorsement, oﬀers a reliable foundation for your projects. With battle-tested configurations and proven reliability across 300+ microservices, it's the ideal starting point for robust Express applications.

Balkan Olympiads

Participated in The Balkan Olympiad in Informatics in 2013, in Sarajevo, Bosnia, and in 2014, in Ankara, Turkey. I also participated in The Junior Balkan Mathematical Olympiad (JBMO) in 2012, in Veria, Greece.

Education

2016 - 2019

Bachelor's Degree in Computer Science

Metropolitan State University - Minnesota, USA

Skills

Libraries/APIs

jQuery, Google API, Stripe API, Vue, React, Node.js, REST APIs, API Development, Stripe, Braintree API, PayPal API, Facebook API

Tools

Git, Prisma, BigQuery, Jenkins, Kibana, DataGrip, ElectricFlow, Traefik

Languages

SQL, HTML5, CSS3, HTML, PHP, CSS, JavaScript, TypeScript, Ruby, ECMAScript (ES6), Sass, SCSS, Go, GraphQL, Java, Python

Frameworks

Laravel, Ruby on Rails (RoR), Express.js, Jest, Next.js, Bootstrap, PHPUnit, Yii, Slim, Angular, NestJS, gRPC, Tailwind CSS, AngularJS, Nuxt.js

Paradigms

Object-oriented Design (OOD), Object-oriented Programming (OOP), Microservices, REST, Test-driven Development (TDD), Business Intelligence (BI)

Platforms

Linux, Amazon EC2, Amazon Web Services (AWS), Windows, Docker, Apache Kafka, WordPress, Visual Studio Code (VS Code), MacOS, Embedded System Design (ESD), Kubernetes

Storage

MySQL, MariaDB, PostgreSQL, MongoDB, Redis, JSON, Amazon DynamoDB, Databases, Elasticsearch, SQLite, Database Management Systems (DBMS)

Other

APIs, Design Principles, TypeORM, Fintech, Online Banking, Digital Payments, Mobile Banking, Payment APIs, Full-stack, API Integration, Distributed Systems, Back-end Development, Front-end Development, Front-end, SDKs, Architecture, Authentication, Data Engineering, Full-stack Development, Software Architecture, System Design, OpenAI GPT-4 API, OpenAI GPT-3 API, Single Sign-on (SSO), Payment Gateways, Machine Learning, Artificial Intelligence (AI), Chrome Extensions, AI Chatbots, Chatbots, Stripe Payments, Computer Science, Discrete Mathematics, Logic Design, Data Structures, Digital Signal Processing, PostgreSQL 9, Electronics, Integrated Circuits, Signals, Systems, Programming, Card Payments, Computer Architecture, Linear Algebra, Calculus, Graph Theory, Mathematics, Algorithms

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