91 Pay, is an enterprise-grade, API-first remittance and currency-exchange platform. The platform now enables businesses to move large sums of money globally with transparent, wholesale rates and developer-friendly integrations across six major fiat currencies and USDT.
Backend Engineer
Full-time available
Bio
John O, is a backend-focused Software Engineer with over seven years of experience building and scaling production-grade systems across fintech, SaaS, e-commerce, and API-driven platforms. He specializes in TypeScript, Node.js, NestJS, Python, and FastAPI, with strong expertise in designing RESTful and GraphQL APIs that serve thousands of concurrent users. His technical skill set spans cloud-native infrastructure and DevOps practices, including AWS and Azure services, Docker, Kubernetes, Linux, Nginx, CI/CD pipelines, and…
Expertise
NodeJSMongoDBGraphQLKafkaPythonReactAWSTypescriptReact NativeNextJSFast APIKubernetesSQLGitCSSC++WebScrapingDatabase:RelationalDatabase:DocumentDatabase:Cacheing
Video Intro
Assessments
Projects
An AI-powered application described as the Shazam for Christian sermons. Users can discover sermon matches and explore a vast library of spiritual messages. I was responsible for the backend and AI services. I made use of Typescript, NestJS, TypeORM, Python, Fast API, LLM integrations and Vector Databases
Gaia AI is a platform that uses AI-powered matching to connect people based on their ideas or projects. It helps users find potential co-founders, collaborators, or supporters who share similar visions for the future. It makes uses of AI to automatically create users profiles. AI powered voice onboarding is built-in, to make the onbaording process seamless and interactive
Experience
Software Engineer
Grey Invent TechnologiesJun 2025 — Present- Led mobile development for, 91 Payments, fintech app using React Native and Expo, launched to production serving 3,000+ active users across iOS and Android
- Currently leading mobile development for Kloutpay, a creator-focused fintech platform
- Managed deployment pipeline for Google Play Store and Apple App Store releases
- Developed frontend applications and admin panels with Next.js and Tailwind CSS, translating Figma designs into pixel-perfect production interfaces
- Optimized app performance achieving 40% faster load times and 95%+ crash-free rate through efficient state management and code optimization
- Collaborated with QA teams in Agile sprints to ensure quality API integrations and seamless user experience across mobile and web platforms
Node.jsAWSTypescriptAWS AmplifyNext.jsReactReact NativeExpoC#Software Engineer I
Left Lane TechnologiesOct 2023 — Sep 2025- Led 5-member engineering team across frontend, backend, and cloud infrastructure, delivering 4 products in fintech, e-commerce, and SaaS with 3x faster shipping velocity
- Architected and developed scalable REST and GraphQL APIs using TypeScript, Node.js, NestJS, Python, and FastAPI serving thousands of concurrent users
- Developed frontend applications with Next.js and TailwindCSS, delivering responsive user interfaces and admin dashboards
- Implemented comprehensive unit testing with Jest achieving 85%+ code coverage, ensuring code reliability and reducing production bugs
- Integrated Stripe and Paystack payment gateways across multiple projects, implementing secure transaction processing and webhook handling
- Designed and implemented microservice architecture using RabbitMQ and FastAPI for async task processing, reducing API response times by 60%
- Managed AWS infrastructure (S3, SES, SNS, Lambda, API Gateway, Elastic Beanstalk, CodePipeline) ensuring 99.9% uptime and scalability
- Oversaw technical communications between engineering teams and management, ensuring alignment on deliverables and sprint goals
TypeScriptNode.jsNestJSPythonFastAPINext.jsTailwindCSSJestStripePaystackRabbitMQGraphQLAWS S3AWS LambdaAWS SESAWS Elastic BeanstalkBackend Engineer
Credit CliqNov 2023 — Mar 2025- Integrated APIs with 3 major credit bureaus across US, Canada, and India, ensuring SOC2 compliance and adherence to regional security regulations
- Built backend systems for mobile app serving 10,000+ users, enabling credit report access, identity verification, and credit building through bill payments
- Developed credit-building features allowing users to improve credit scores via airtime purchases and electricity bill payments
- Built robust REST APIs with Node.js, Hono.js, TypeScript, MongoDB, and Redis for efficient credit data processing and real-time identity verification
- Implemented AWS Cognito for secure user authentication and authorization across mobile and admin applications
- Integrated Stripe and Paystack payment services for automated invoice and subscription management
- Developed microservice applications using Apache Kafka, and AWS Lambd for scalablitity when fetching credit reports
- Established CI/CD pipelines with GitHub Actions and AWS CDK for automated deployments and infrastructure management
Node.jsHono.jsTypeScriptMongoDBRedisAWS CognitoStripePaystackApache KafkaAWS LambdaGitHub ActionsAWS CDK
Education
BSc Computer Science
Mountain Top UniversityOgun, Nigeria2019 — 2023
Backend Engineer
Full-time available
John is available for hire
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Bio
John O, is a backend-focused Software Engineer with over seven years of experience building and scaling production-grade systems across fintech, SaaS, e-commerce, and API-driven platforms. He specializes in TypeScript, Node.js, NestJS, Python, and FastAPI, with strong expertise in designing RESTful and GraphQL APIs that serve thousands of concurrent users. His technical skill set spans cloud-native infrastructure and DevOps practices, including AWS and Azure services, Docker, Kubernetes, Linux, Nginx, CI/CD pipelines, and…
- Projects completed3
- Hourly rate
- 3-4 years experience
- Member since Jan 2026
Expertise
NodeJSMongoDBGraphQLKafkaPythonReactAWSTypescriptReact NativeNextJSFast APIKubernetesSQLGitCSSC++WebScrapingDatabase:RelationalDatabase:DocumentDatabase:Cacheing
Video Intro
Assessments
Projects
91 Pay, is an enterprise-grade, API-first remittance and currency-exchange platform. The platform now enables businesses to move large sums of money globally with transparent, wholesale rates and developer-friendly integrations across six major fiat currencies and USDT.
An AI-powered application described as the Shazam for Christian sermons. Users can discover sermon matches and explore a vast library of spiritual messages. I was responsible for the backend and AI services. I made use of Typescript, NestJS, TypeORM, Python, Fast API, LLM integrations and Vector Databases
Gaia AI is a platform that uses AI-powered matching to connect people based on their ideas or projects. It helps users find potential co-founders, collaborators, or supporters who share similar visions for the future. It makes uses of AI to automatically create users profiles. AI powered voice onboarding is built-in, to make the onbaording process seamless and interactive
Experience
Software Engineer
Grey Invent TechnologiesJun 2025 — Present- Led mobile development for, 91 Payments, fintech app using React Native and Expo, launched to production serving 3,000+ active users across iOS and Android
- Currently leading mobile development for Kloutpay, a creator-focused fintech platform
- Managed deployment pipeline for Google Play Store and Apple App Store releases
- Developed frontend applications and admin panels with Next.js and Tailwind CSS, translating Figma designs into pixel-perfect production interfaces
- Optimized app performance achieving 40% faster load times and 95%+ crash-free rate through efficient state management and code optimization
- Collaborated with QA teams in Agile sprints to ensure quality API integrations and seamless user experience across mobile and web platforms
Node.jsAWSTypescriptAWS AmplifyNext.jsReactReact NativeExpoC#Software Engineer I
Left Lane TechnologiesOct 2023 — Sep 2025- Led 5-member engineering team across frontend, backend, and cloud infrastructure, delivering 4 products in fintech, e-commerce, and SaaS with 3x faster shipping velocity
- Architected and developed scalable REST and GraphQL APIs using TypeScript, Node.js, NestJS, Python, and FastAPI serving thousands of concurrent users
- Developed frontend applications with Next.js and TailwindCSS, delivering responsive user interfaces and admin dashboards
- Implemented comprehensive unit testing with Jest achieving 85%+ code coverage, ensuring code reliability and reducing production bugs
- Integrated Stripe and Paystack payment gateways across multiple projects, implementing secure transaction processing and webhook handling
- Designed and implemented microservice architecture using RabbitMQ and FastAPI for async task processing, reducing API response times by 60%
- Managed AWS infrastructure (S3, SES, SNS, Lambda, API Gateway, Elastic Beanstalk, CodePipeline) ensuring 99.9% uptime and scalability
- Oversaw technical communications between engineering teams and management, ensuring alignment on deliverables and sprint goals
TypeScriptNode.jsNestJSPythonFastAPINext.jsTailwindCSSJestStripePaystackRabbitMQGraphQLAWS S3AWS LambdaAWS SESAWS Elastic BeanstalkBackend Engineer
Credit CliqNov 2023 — Mar 2025- Integrated APIs with 3 major credit bureaus across US, Canada, and India, ensuring SOC2 compliance and adherence to regional security regulations
- Built backend systems for mobile app serving 10,000+ users, enabling credit report access, identity verification, and credit building through bill payments
- Developed credit-building features allowing users to improve credit scores via airtime purchases and electricity bill payments
- Built robust REST APIs with Node.js, Hono.js, TypeScript, MongoDB, and Redis for efficient credit data processing and real-time identity verification
- Implemented AWS Cognito for secure user authentication and authorization across mobile and admin applications
- Integrated Stripe and Paystack payment services for automated invoice and subscription management
- Developed microservice applications using Apache Kafka, and AWS Lambd for scalablitity when fetching credit reports
- Established CI/CD pipelines with GitHub Actions and AWS CDK for automated deployments and infrastructure management
Node.jsHono.jsTypeScriptMongoDBRedisAWS CognitoStripePaystackApache KafkaAWS LambdaGitHub ActionsAWS CDK
Education
BSc Computer Science
Mountain Top UniversityOgun, Nigeria2019 — 2023
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