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Hello, I'm Opeoluwa Siyanbola. I'm a Full Stack Developer with 6 years of experience building and scaling full-stack products across fintech, AI and pharmaceutical industries. Specializing in full-stack development, backend development, and frontend development and LLM trainning and integration.

About me

Senior Software Engineer with 6+ years of experience building and scaling full-stack products across fintech, AI, pharmaceutical, content, and sports industries. Specialized in React.js, React Native, TypeScript, Redux, and React Query for building performant, user-centric applications, with strong expertise in Tailwind CSS and shadcn/ui for modern UI systems. Backend expertise includes Node.js, RESTful API design, cloud-native architectures, and asynchronous processing. Highly proficient in AWS, MongoDB, PostgreSQL, Redis, and CI/CD pipelines using GitHub Actions. Consistently delivers business-critical systems for LLM applications, personalization engines, and high-throughput financial platforms while mentoring engineers and leading execution under tight timelines.

Works

Sigma

An AI-Driven Financial Excellence for fraud detection, credit risk assessment, and financial analysis.

React
Node.js
Next.js
MongoDB
Tailwind
AWS
Redux Toolkit

SwiftMoney

A versatile digital wallet offering seamless money transfers, access to interest-free credit up to N10M, and the opportunity to build credit scores in one convenient app.

React
Node.js
Next.js
MongoDB
Tailwind
AWS

Spoxio

A social media platform for athletes that connects sport talents with scouts and managers in a social and secure way.

React Native
Node.js
MongoDB

SABI - BOOKKEEPING & RECEIPTS

Streamlined digital bookkeeping for small businesses, offering easy transaction monitoring, customer management, and cost-effective insights through a smartphone interface.

React
Node.js
Next.js
MongoDB
Tailwind
AWS

My skills

Typescript
React.Js
Node.Js
React Native
MongoDB
AWS
Express.Js
Tailwind CSS
Framer Motion
Jest
React Testing Library
Git

My experience

Senior Full Stack Developer

DataServe AI. Inc. (Remote)

United States

Contributed to the development of a real-time AI-powered fraud detection system to evaluate users and transactions, significantly reducing fraudulent activity and financial risk.Built a robust custom rules system for monitoring transaction and making decisions based on the predefined rules. Designed and developed a multi-app integrated ERP dashboard with role- and permission-based access, enabling unified management across business applications. Architected and launched a multi-tier, multi-wallet payment system for sending and receiving payments in Nigeria, improving transaction efficiency and accessibility. Built a multi-provider payment routing system that dynamically leverages multiple providers to guarantee 100% transaction uptime.

2023 - Present

Senior Software Engineer - LLM Training (Google Gemini)

Turing

Remote

Simulated engineering workflows for RLHF/SFT pipelines supporting LLM trainingContributed to advancements in dataset production, optimizing data variety and volume to meet the training needs of advanced models. Delivered prompt-level metadata to AI research teams for output tuning Promoted to a POD Lead where I orchestrated the training and onboarding of new engineers. Led and mentored software development teams across multiple projects from inception to delivery.

2024-2025

Full Stack Developer

Topcoder

Signapore . Remote

Engineered responsive, scalable web applications using React, Next.js, TypeScript, and Ant Design, significantly improving user experience and system performance. Ensured quality and reliability through unit testing with Jest and React Testing Library, reducing production defects and improving application stability. Developed and maintained backend services with Express, streamlining workflows and optimizing system performance. Refined user stories and requirements in close collaboration with business teams, ensuring solutions aligned with end-user needs.

2022 - 2023

Mobile Developer (React Native)

Spoxio

United Kingdom

I worked on a cross-platform mobile application using react-native. Building re-usable custom components and hooks, Conversion and estimations of business requirements into technical refinements for development. Collaborated with the backend development to define data objects needed for rendering UI on the client Deployment of application on the apple store and play store

2021-2023

Interview Question Curator

Toggl Hire (Contract)

Estonia . Remote

I work closely with a team of experts in creating high-quality and effective interview questions that accurately assess candidates' skills and qualifications. Collaborate with a team of experts to develop comprehensive interview question sets for different roles and positions. Conduct thorough research and stay updated on industry trends and best practices in interview assessments. Analyze job descriptions and requirements to understand the key competencies and qualifications needed for each position.

2023

Full Stack Developer

Startupia LLC

Lagos, Nigeria

Design and maintain applications using React.js, Redux and Typescript. Design and maintain mobile applications using React Native. Develop backend services using Express and Node.js. Perform code reviews on applications

2018 - 2021

Contact me

Please contact me directly at opesiyanbola8991@gmail.com or through this form.