
Jesupelumi Adetunji
Verified Expert in Engineering
Software Developer
Lagos, Nigeria
Toptal member since November 3, 2020
Jesupelumi is a front-end and mobile developer with expert-level skills in React, Angular, Vue, and Flutter. He developed a web application using cutting-edge technology for Oceaneering, a top firm in marine engineering. Jesupelumi has worked with a range of clients across industries from marine engineering, energy, education, and telemedicine in supervisory and development roles. He is consistent, flexible, and enjoys seeing his products used to help people.
Portfolio
Experience
- React - 9 years
- JavaScript - 9 years
- Redux - 5 years
- HTML - 5 years
- CSS - 5 years
- Vue - 5 years
- Flutter - 4 years
- Angular - 3 years
Preferred Environment
Visual Studio Code (VS Code), Visual Studio, Slack, Windows, MacOS
The most amazing...
...web application I've worked on was OMV, using cutting-edge technology for Oceaneering, a top firm in marine engineering.
Work Experience
Software Architect | Full-stack Developer
Tyler J Rowser
- Joined as the software architect on a greenfield sports platform, setting technical direction across web, mobile, back end, and infrastructure—making the foundational decisions on monorepo structure, data model, auth strategy and deployment topology.
- Built the platform as a Turborepo monorepo with 2 Next.js web applications and a React Native mobile application sharing types, business logic, and Supabase client code—eliminating cross-platform drift and accelerating feature parity from day one.
- Established the Supabase back-end foundation, including Postgres schema design, authentication, row-level security policies, and storage, providing a unified data layer for both the web and mobile clients.
- Configured the production deployment pipeline on Vercel for the web tier and the mobile build pipeline for iOS and Android, with CI/CD discipline carried over from prior production engagements.
Full-stack Developer
D2Labs, LLC
- Took a Lovable-generated AI prototype to production-ready quality by refactoring for type safety, performance, error handling, and maintainable architecture—turning a fast-shipping prototype into a reliable platform suitable for real users.
- Completed and stabilized the authentication flow end-to-end, covering sign-up, sign-in, session handling, protected routes, and edge cases that the original prototype had left incomplete.
- Rebuilt multiple full pages from the ground up where the AI-generated baseline did not meet production standards, restructuring components for reusability, accessibility, and consistent design system adherence.
- Integrated Supabase (Auth and PostgreSQL) and AWS infrastructure end-to-end, owning the productionization of the back-end layer, including schema design, row-level security, and deployment configuration.
Back-end Developer
Seeshare, L.L.C.
- Delivered the final 20% of a Next.js 14 security-scanning SaaS platform, taking it from a locally-hosted prototype to a production-ready application deployed to Vercel with Docker-based scanner workers running on DigitalOcean.
- Built a multi-worker scanner architecture that runs OWASP ZAP, Nmap, OpenVAS, Nuclei, RetireJS, WPScan, and custom GDPR scanners in isolated Docker containers, with per-scanner routing and graceful cancellation of long-running scans.
- Diagnosed and fixed a concurrency race condition on the ZAP worker, serialized ZAP scans, paginated alert retrieval up to 5,000 findings per scan, and added active-scan cleanup so large-site scans no longer time out or crash the worker.
- Designed and shipped a full Stripe billing system covering subscription tiers, yearly/monthly intervals, per-domain plans, one-time scans, sales-team accounts, billing-exempt users, coupon/promotion codes.
- Rebuilt the domains management module with a redesigned UI, new API endpoints, scanner-metadata surfacing, and a scans-summary endpoint backed by PostgreSQL aggregation for dashboard load performance.
- Built an action-sessions feature giving the team authenticated, auditable sessions for sensitive in-app actions.
- Resolved Docker networking issues that prevented the Next.js app from reaching the ZAP container on Coolify and Vercel by auto-connecting the worker to the scanner Docker network and using the bridge gateway IP for container-to-container calls.
Front-end Developer
ESAB - Global Marcom & North America
- Rebuilt the global mega‑navigation, unifying UX across brands and locales.
- Delivered a product compare module enabling side‑by‑side spec evaluation for up to four items with reusable UI components.
- Overhauled product details pages, refactoring overview/ordering sections, and unifying styles for dozens of SKUs.
- Implemented a gas calculator experience integrated into product flows to help users estimate shielding‑gas needs.
- Improved on‑site search, refining UI and query handling while removing dead code and duplicates discovered during cleanup.
- Launched category/brand landing templates, streamlining content for 6+ market segments.
Front-end Developer
Lifestyles Discovery LLC
- Conducted UI audits across devices, fixing layout and styling inconsistencies in Vue applications.
- Enhanced user experience by addressing table scrolling and responsive formatting issues.
- Refreshed application styles and colors to align with the company’s updated branding.
- Improved cross-device compatibility, ensuring a seamless experience for mobile and desktop users.
Senior Front-end Developer
MobilSense Technologies, Inc.
- Maintained and optimized React and Angular SaaS platform for wireless communication services.
- Refactored front-end modules for performance improvements, reducing load time across key workflows.
- Provided technical guidance on best practices for front-end architecture and scalability.
- Migrated legacy AngularJS code to modern Angular 9+, improving maintainability and aligning with updated architecture standards.
- Refactored state management by introducing Zustand in the React front end, simplifying store logic, and reducing boilerplate.
Flutter Expert
ASDai, LLC
- Migrated legacy SwiftUI codebase to Flutter, enabling cross-platform deployment on iOS and Android.
- Implemented multiple Flutter widgets and navigation flows to support daily caregiver routines.
- Integrated Firebase services for authentication, storage, and real-time data syncing.
- Released the Rootines app to both the Play Store and App Store, improving accessibility for the autism community.
- Reduced code maintenance overhead by consolidating the native iOS app into a single Flutter codebase.
Angular Developer
AltaML, Inc
- Implemented multi‑tenancy for clinics and vets, including data segregation and permissions, enabling safe tenant isolation and simpler rollout across environments.
- Migrated the parent schema and wrote unit tests for old/new models, ensuring backward compatibility and a zero‑downtime release during data migration.
- Built the statistics dashboard for default clinics, surfacing adoption and engagement metrics to stakeholders, and reducing manual reporting time.
- Added pagination to the parents listing to handle large datasets, cutting initial payloads and improving page load time significantly (e.g., >80% reduction).
- Shipped email/password authentication UX with “Forgot password”, improving the sign‑in experience and lowering auth‑related support tickets.
- Resolved a critical sign‑in flow bug that blocked users from progressing to the next page, restoring the onboarding funnel and reducing drop‑offs.
- Introduced state‑management improvements across onboarding forms, reducing UI inconsistencies and simplifying future feature work.
Senior React Front-end Developer
Funl
- Built and maintained complex React components for a marketing analytics platform, ensuring scalability and performance.
- Integrated 3rd-party SDKs (e.g., Sisense) into front-end workflows, providing advanced analytics visualizations.
- Collaborated with a global team across multiple time zones, contributing to rapid feature delivery and UI enhancements.
JavaScript Developer
Reward Gateway, Limited
- Developed an Office 365 eCard extension with React and TypeScript, enabling employees to send recognition cards directly via Outlook.
- Integrated extension APIs to sync with Reward Gateway’s recognition platform, increasing user engagement.
- Delivered cross-platform functionality, building on prior G Suite extension experience to expand client adoption.
Angular Developer
Veritic Solutions, Inc
- Polished and optimized Angular 9+ login and product pages, improving page responsiveness and usability.
- Enhanced front-end performance by refactoring data flows, resulting in faster navigation across product features.
- Collaborated with the SaaS team to streamline forecasting workflows and deliver a cleaner UI experience.
Front-end Developer
Veritic Solutions
- Added security to the application using Auth0's SDK with login and signup components and authorization within the application.
- Designed a forecast page using AntDesign's components based on data from the back end.
- Embellished existing pages with better component structure and styles, including several tables and progress cards.
Mobile Developer
Freelance
- Developed a Flutter app that manages the activities of freight carriers, including their trucks, drivers, requests, and trips.
- Implemented BLoC pattern for state management within the app.
- Implemented a feature for downloading, uploading, and viewing documents and images.
Front-end Developer
Freelance
- Developed an app that allows the admin to manage the activities of freight carriages.
- Constructed an app that allows users to book and request the movement of goods from one state to another in Nigeria.
- Implemented state management using Redux and Redux Thunk as middleware to pass data between modules.
- Tracked and fixed bugs using Azure DevOps as a reporting tool.
Mobile Developer
Eminent Technology
- Developed a telemedicine app using Flutter, which enables patients to receive consultation via video or voice calls and is used by various health centers and hospitals.
- Built an app with Xamarin.Forms that helps reunify students and their guardians during emergencies in the US.
- Constructed an app using Xamarin.Forms that allows users to make donations to charity organizations and religious centers. The app included scheduling and the ability to make recurring donations.
- Oversaw major enhancements to the Second Baptist Church app that helps Bible study leaders manage their study sessions.
Lead Front-end Developer
Eminent Technology
- Developed a web media library that provides a collaborative platform for video calls, annotation, and chat using Angular, NGXS, and Twilio SDK.
- Created jobs using Azure Batch Service to run tasks, such as optical character recognition (OCR) and conversion of speech to text.
- Handled image, video, and document uploads to Azure Blob Storage.
- Developed a desktop application for uploading large files to Azure Blob Storage to pause and cancel using Electron and Angular.
- Tracked and fixed bugs using Azure DevOps as a reporting tool.
- Built a Vue-based university website that provides respective campuses' energy-saving metrics and blog posts, stories, and information about events or duels.
- Developed a telemedicine web application using Vue and .NET, which allows doctors and healthcare providers to manage patients and their data/records within a virtual facility used by several health centers and hospitals.
Experience
TheWordCity — Church Web Platform & Sermon Library
https://thewordcityglobal.comHanya — Multi-tenant Poultry Farm Management Platform
It is currently live on staging at staging.tryhanya.com, with production launch planned.
Yara Timer - Professional Presentation Timer Application
https://yaratimer.comTheCable App
https://play.google.com/store/apps/details?id=ng.thecable.app&hl=en&gl=USAndroid: Play.google.com/store/apps/details?id=ng.thecable.app&hl=en&gl=US
iOS: Apps.apple.com/ng/app/thecable/id6446224303
Issua Logistics
Telemed Web and App
Web: https://www.telemed.com.ng/
App: https://play.google.com/store/apps/details?id=ng.com.telemed.patientapp&hl=en&gl=US
Engie Smart Institutions
I worked with a team of four on the front end while integrating with the API resources provided by the Strapi back end. Vuex was used for state management and Fuse to complete a complex search on multiple entities such as buildings, stories, and events.
Toptal React Academy
Education
Bachelor of Science Degree in Food Technology
University of Ibadan, Nigeria - Ibadan, Nigeria
Certifications
Toptal React Academy Graduate
Toptal, LLC
Skills
Libraries/APIs
React, Vue, React Query, jQuery, Node.js, Web API, REST APIs, Socket.IO, Vue 3, Vue 2, NgRx, NGXS, Chart.js, Azure Blob Storage API, Stripe, Vuex, Google Speech API, Microsoft Word Add-on Development, HeroUI, YouTube API, Claude API, React Hook Form, Zod, Framer Motion, OpenAI API
Tools
Git, Claude, Shadcn, Firebase Authentication, Figma to HTML, Claude Code, GitHub, Jira, Fuse, Auth0, Crashlytics, OneSignal, Flyway, Expo, Seos, Drizzle ORM, Docker Compose, Shadcn UI, NMap, WPScan
Languages
HTML5, CSS3, JavaScript, SQL, CSS, HTML, Dart, TypeScript, Sass, SCSS, C#.NET, C#, Batch, Swift, Coolify
Frameworks
Redux, Angular, Flutter, Vanilla JS, Next.js, Tailwind CSS, NestJS, Express.js, Bootstrap, Swagger, Riverpod, .NET, React Native, .NET Core, OAuth 2, JSON Web Tokens (JWT), OpenVAS
Paradigms
Responsive Coding, Mobile Development, API Architecture, Responsive Web Design (RWD), Testing, Responsive Layout
Platforms
Google Cloud Platform (GCP), Mobile, Firebase, Android, iOS, Vercel, Adobe ColdFusion, Azure, Twilio, MacOS, Docker, DigitalOcean, Amazon Web Services (AWS)
Storage
PostgreSQL, Microsoft SQL Server, Elasticsearch, Realm, Redis
Other
Responsive Design, Axios, Push Notifications, Web UI, Front-end, Responsive UI, SaaS, APIs, User Interface (UI), User Experience (UX), API Integration, Full-stack, Styled-components, Front-end Development, AI Tools, Headless CMS, Full-stack Development, RESTFul APIs, Websites, Supabase, Application State Management, Pixel Perfect, Reusable Libraries, UI Components, API Design, Back-end, Cursor AI, Architecture, Back-end Development, App Store, Google Play Store, Software Architecture, Minimum Viable Product (MVP), Mobile App Development, Supabase Auth, Artificial Intelligence (AI), Zustand, Tanstack Query, Vite, Strapi, CI/CD Pipelines, Technical Leadership, Headless Commerce, Security, UI Animation, Pinia, OAuth, Payment APIs, Charts, Material Design, Optical Character Recognition (OCR), Speech-to-Text (STT), Analytics, Office 365, Consulting, Chrome Extensions, Natural Language Processing (NLP), Machine Learning, Office Add-ins, Generative Pre-trained Transformers (GPT), Troubleshooting, Cloudflare, Turborepo, Full-text Search, Multi-tenant Architecture, Multi-factor Authentication (MFA), OWASP, GDPR, BullMQ, Resend, Coding, QR Codes, Stripe Terminal
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