Olarewaju Akeem Opeyemi, Developer in Lagos, Nigeria
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Olarewaju Akeem Opeyemi

Bio

Opeyemi is a senior full-stack engineer specializing in high-performance web applications built with React, Node.js, and TypeScript. He has delivered scalable, responsive platforms used by thousands of users, focusing on performance optimization and real-time user experiences. Opeyemi builds clean, reliable interfaces that help teams ship faster and scale confidently

Portfolio

cashandchat
React, React Native, Node.js, Next.js, WebSockets, Parse Server, JavaScript...
Tropic Seascape Pte Ltd
JavaScript, React, CSS, Web3.js, Blockchain, Cryptocurrency Wallets, Gaming...
Ejobkit
React, Redux, Redux Form, Redux-Saga, Parse Server, Material UI, Gatsby, HTML...

Experience

  • Redux-Saga - 10 years
  • JavaScript - 10 years
  • React - 10 years
  • Redux - 9 years
  • TypeScript - 9 years
  • Next.js - 8 years
  • Material UI - 5 years
  • Gatsby - 2 years

Preferred Environment

Jira, Docker, Blockchain, Capacitor, Artificial Intelligence (AI), Node.js, React, Python, TypeScript, React Native

The most amazing...

...projects I've collaborated on included a React Native-based investment mobile app for Africans and a React-based web KYC app built for chats and video calls.

Work Experience

Senior Full-stack Engineer

2022 - 2026
cashandchat
  • Designed and developed a real-time chat platform enabling paid interactions for use cases such as consultation, counseling, and social engagement.
  • Built cross-platform web and mobile applications using React, React Native, and Capacitor.js, ensuring seamless user experience across devices.
  • Implemented real-time communication systems using WebSockets, Socket.IO, and Simple-Peer (WebRTC), enabling low-latency messaging and video interactions.
  • Developed back-end services with Node.js and Parse Server, handling authentication, user sessions, and real-time data synchronization.
  • Designed a scalable front-end architecture with TypeScript and Material UI, improving maintainability and UI consistency.
  • Optimized real-time data flows and UI updates, ensuring responsive performance under concurrent user activity.
  • Navigated platform compliance challenges (App Store policies), gaining experience in product constraints, risk assessment, and platform governance.
Technologies: React, React Native, Node.js, Next.js, WebSockets, Parse Server, JavaScript, TypeScript, Redux, Redux Toolkit, Socket.IO, REST, GraphQL, Server-side Rendering (SSR), Express.js, Docker, GitHub, Jira, CI/CD Pipelines, Agile, Cypress, Jest, Figma, API Integration, Tailwind CSS

Senior Front-end Engineer

2021 - 2022
Tropic Seascape Pte Ltd
  • Built a platform from scratch where new games in the NFT world can launch their application and participate in lotteries at seascape.house using Next.js for the UI and ether packages for wallet connections.
  • Built a platform from scratch for the Blocklords game, where gamers can track and buy NFTs and participate in lotteries and special offers at blocklords.com using Next.js for the UI and IMX and ether packages for wallet connections and NFT transactions.
  • Managed and maintained an existing Gatsby application using WordPress API with the gatsby-source-wordpress plugin.
  • Developed a large-scale NFT marketplace using React and TypeScript, supporting 200,000+ users and enabling real-time asset trading across blockchain networks.
  • Integrated blockchain transaction flows using Ethers.js and Immutable X, improving wallet connection success rates and reducing onboarding friction.
  • Optimized UI rendering and data synchronization for high-frequency blockchain updates, improving responsiveness by around 40% under peak load.
  • Designed a front-end architecture for transaction flows aligned with smart contracts, reducing failed transactions and improving system reliability.
  • Collaborated with cross-functional teams to deliver scalable features supporting multi-game ecosystems and increasing user engagement.
Technologies: JavaScript, React, CSS, Web3.js, Blockchain, Cryptocurrency Wallets, Gaming, Casinos & Gaming, Immutable X, Ethereum Smart Contracts, Ethereum, Ethers.js, Next.js, MetaMask, Blockchain Wallets, Agile, CI/CD Pipelines, API Integration

Full-stack Developer

2020 - 2021
Ejobkit
  • Managed a team of front-end developers to build a sleek, responsive, and attractive landing page using Material-UI with captivating React features that met SEO standards (used Gatsby).
  • Led a team of front-end developers to build a section of an application dashboard where clients, freelancers, and affiliates can interact and also manage their accounts using React and TypeScript.
  • Oversaw a team of back-end developers to build a back end that accommodates the application's mobile and web users using Parse Server.
  • Built a multi-tenant freelance marketplace platform supporting thousands of concurrent users with real-time interactions across client and freelancer workflows.
  • Developed responsive front-end interfaces using React and Gatsby, improving SEO performance and increasing organic traffic by over 50%.
  • Implemented role-based dashboards and optimized API orchestration, improving data retrieval efficiency and user experience.
  • Managed complex asynchronous flows using Redux-Saga, ensuring stable real-time behavior and reducing front-end defects.
  • Integrated back-end services using Node.js and Parse Server, creating a unified API layer across web and mobile platforms.
  • Introduced end-to-end testing with Cypress, improving release reliability and reducing regression issues.
Technologies: React, Redux, Redux Form, Redux-Saga, Parse Server, Material UI, Gatsby, HTML, CSS, User Interface (UI), Cypress, Slack, MacOS, JavaScript, TypeScript, Node.js, Visual Studio Code (VS Code), Git, GitHub, Startups, Create React App, HTML5, Front-end, MongoDB, PostgreSQL, WebSockets, Socket.IO, Jest, SEO Tools, Agile, CI/CD Pipelines, Full-stack, API Integration

React and React Native Developer

2018 - 2020
Rise
  • Managed a team of front-end developers to build and manage a fast investment mobile application using React Native and TypeScript.
  • Led a team of front-end developers to build a customer management tool that assisted staff with interacting with investors and taking admin actions such as editing user profiles, payments, and withdrawals on behalf of investors.
  • Oversaw a team of front-end developers to build a platform affiliate program dashboard where affiliates can see their earnings and track their progress.
  • Developed a cross-platform investment application using React Native, supporting thousands of users and improving transaction speed and reliability.
  • Built real-time dashboards for internal operations, enabling transaction monitoring and improving operational efficiency for support teams.
  • Implemented affiliate and analytics platforms to track user acquisition and conversion flows, supporting business growth initiatives.
  • Optimized API integration and asynchronous data handling, reducing latency by around 30–40% and improving application responsiveness.
  • Improved mobile stability by addressing performance bottlenecks, reducing crash rates and enhancing user experience across iOS and Android.
Technologies: JavaScript, TypeScript, React, React Native, Redux, Redux Form, Redux-Saga, HTML, CSS, APIs, User Interface (UI), Slack, MacOS, Xcode, Android Studio, Material UI, Visual Studio Code (VS Code), Git, GitHub, Startups, Create React App, HTML5, Front-end, Agile, API Integration

Web Engineer

2018 - 2018
Numbrs
  • Built a WebRTC-based KYC communication platform enabling real-time video and chat for identity verification at scale.
  • Developed scalable front-end systems using React and TypeScript, improving onboarding flow efficiency and user completion rates.
  • Implemented reusable component architecture, accelerating feature delivery and ensuring UI consistency across products.
  • Introduced testing practices that reduced defects and improved system stability in production environments.
Technologies: JavaScript, TypeScript, Redux, Redux-Saga, Redux Form, React, WebRTC, HTML, CSS, APIs, User Interface (UI), Slack, MacOS, Node.js, Visual Studio Code (VS Code), Git, HTML5, Front-end, Jest, Agile, Jira, API Integration

Full-stack Developer

2015 - 2017
Online Freelance Agency
  • Contributed to full-stack web applications using JavaScript, Node.js, and modern front-end frameworks.
  • Built reusable UI components and integrated back-end APIs, improving development efficiency and code reuse.
  • Collaborated in agile teams, delivering features in fast-paced development environments.
Technologies: JavaScript, React, Node.js, PostgreSQL, MongoDB, Flux, HTML, CSS, Slack, MacOS, Visual Studio Code (VS Code), Git, GitHub, Create React App, HTML5, Front-end, Express.js, Agile, Jira, API Integration

GIS/Web Developer

2014 - 2015
GIS
  • Developed web applications using HTML, CSS, and JavaScript, building foundational front-end engineering skills.
  • Worked on GIS-based web solutions, integrating mapping data and improving user interaction with location-based services.
  • Improved company revenue with optimized mapping and GIS architecture.
Technologies: JavaScript, HTML, CSS, CSS3, GIS, jQuery, HTML5, Maps, API Integration

Experience

A Game's NFT Management Application

https://blocklords.com
A successful platform for the Blocklords game with hundreds of thousands of users where gamers can track and buy NFTs and participate in lotteries and special offers. I built from scratch the front end using Next.js for the UI and IMX and ether packages for wallet connections and NFT transactions.

A Game Launch Project for NFT Game Developers

A successful platform with hundreds of thousands of users where new games in the NFT world can launch their application and participate in lotteries to raise funds. I built from scratch the platform's front end using Next.js for the UI and ether packages for wallet connections.

US Investing for Africans

An application that helps Africans invest and manage their money with a portfolio of expertly selected US stocks based on their long-term growth opportunities and quality earnings. The investment portfolio is made up of corporate heavyweights like Google, Apple, Tesla, Microsoft, and many more.

Real-time Investment Platform (Web & Mobile)

http://www.rise.capital
Developed a high-performance investment platform enabling users to manage portfolios, track transactions, and receive real-time financial updates across web and mobile applications. I led the front-end architecture using React, React Native, and TypeScript, focusing on scalability, responsiveness, and seamless cross-platform user experience. Implemented real-time data synchronization using WebSockets and optimized API communication to reduce latency and improve transaction speed. Built modular UI components and robust state management using Redux and Redux-Saga to support complex financial workflows. The platform supported thousands of active users and significantly improved transaction reliability and user engagement through performance optimizations and efficient data handling.

WebRTC-based KYC Verification Platform

Built a real-time KYC verification platform enabling secure video communication and chat between users and verification agents. The system was designed to handle high-volume onboarding sessions with low latency and high reliability.
Implemented WebRTC-based peer-to-peer communication and integrated real-time messaging using WebSockets. Developed scalable front-end architecture using React and TypeScript, ensuring smooth user interaction and consistent performance during live sessions.
Optimized connection stability and user experience, significantly improving verification completion rates and reducing onboarding friction for financial applications.

NFT Marketplace for Real-time Digital Asset Trading

https://www.seascape.network
Developed a scalable NFT marketplace supporting high-frequency digital asset transactions for a large user base. The platform enabled users to browse, trade, and manage NFTs in real time with seamless blockchain integration. Integrated smart contract interactions using Ethers.js and Immutable X, ensuring secure and efficient transaction handling. Optimized front-end performance using React and TypeScript to handle frequent data updates and maintain UI responsiveness under load. Improved transaction success rates and reduced failed operations by aligning front-end workflows with blockchain execution processes.

Multi-tenant Freelance Marketplace Platform

Built a full-stack freelance marketplace platform supporting real-time interactions between clients and freelancers. Designed a scalable architecture to handle multiple tenants and high user concurrency.
Developed responsive front-end interfaces using React and Gatsby, improving SEO performance and increasing organic traffic. Implemented role-based dashboards and optimized API orchestration for efficient data retrieval.
Integrated back-end services using Node.js and Parse Server, enabling seamless communication across web and mobile clients while maintaining system scalability and reliability.

Real-time Paid Chat & Consultation Platform

Developed a real-time chat platform enabling users to earn income through conversations across use cases such as consultation, counseling, and social interaction. The system supported live messaging, peer-to-peer communication, and scalable real-time user engagement. Built cross-platform applications using React, React Native, and Capacitor.js, with real-time communication powered by WebSockets and Socket.IO. Implemented back-end services using Node.js and Parse Server, ensuring efficient data handling and scalability.
Integrated WebRTC-based communication using Simple-Peer to support live interaction features. The project was discontinued due to App Store policy restrictions, but demonstrated strong capabilities in building real-time, scalable communication systems.

Education

2008 - 2012

Bachelor's Degree in Computer Science

Federal University of Agriculture Abeokuta - Abeoukuta, Ogun State, Nigeria

Certifications

FEBRUARY 2021 - PRESENT

Meta Front-end Developer Professional Certificate

Meta

MARCH 2020 - PRESENT

Ethereum Developer Certification – Consensys

Consensys

Skills

Libraries/APIs

Redux-Saga, Redux Form, React, Socket.IO, Node.js, WebRTC, Web3.js, jQuery, React Redux, Redux Router, GraphQL API, Natural Language Toolkit (NLTK)

Tools

Slack, Create React App, Capacitor, Figma, Xcode, Android Studio, Git, GitHub, MetaMask, Jira, Postman, Redux Toolkit, GIS, GitHub Copilot, Sequelize

Languages

JavaScript, TypeScript, HTML, CSS, HTML5, Java, GraphQL, CSS3, Python, SQL

Frameworks

Redux, Material UI, Next.js, React Native, Flux, Cypress, Express.js, Jest, Tailwind CSS

Platforms

Parse Server, MacOS, Visual Studio Code (VS Code), Ethereum, Blockchain, Docker

Paradigms

REST, Agile

Storage

PostgreSQL, MongoDB

Other

Gatsby, APIs, User Interface (UI), Front-end, WebSockets, Full-stack, Startups, API Integration, Styled-components, Ethers.js, Ethereum Smart Contracts, Immutable X, Cryptocurrency Wallets, Gaming, Casinos & Gaming, Server-side Rendering (SSR), CI/CD Pipelines, Blockchain Wallets, SEO Tools, Maps, Performance, Peer-to-peer Networking, Web Development, Ethereum Open Source, Ethereum Virtual Machine (EVM), Artificial Intelligence (AI), Deno, Natural Language Processing (NLP), Large Language Models (LLMs)

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