I'm Pappu Kumar Singh, based in Bengaluru, currently working as a Mobile App Engineer with expertise in Full Stack Development. My journey in software development started with web technologies, evolving from a MERN stack developer to building mobile applications using React Native, along with backend services in Spring Boot Microservices, PostgreSQL, Node.js, MongoDB, and MySQL.
- Mobile Development: Building state-of-the-art mobile applications using React Native, focusing on fintech, loan management, and crop insurance.
- Backend Development: Developing microservices with Spring Boot and PostgreSQL, while leveraging Node.js for backend systems that require flexibility and scalability.
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Fintech Mobile App (SenseGrass):
- Built a fintech app similar to Paytm and PhonePe using React Native.
- Integrated payment gateways and processed loans and insurance for farmers.
- Collaborated with developers on backend services using Node.js and MongoDB.
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MoneyPlant Mobile App:
- Developed features like employee loans, stock investments, SIP, credit card applications, and gold loans.
- Led frontend development in React Native and designed the backend architecture using Spring Boot and PostgreSQL.
- Implemented QR code scanning, push notifications, and other critical user flows.
- Frontend: React Native, React, Angular
- Backend: Spring Boot, Node.js, Express
- Databases: PostgreSQL, MySQL, MongoDB
- DevOps: Docker, Git, WebSockets, MQTT
- Other Tools: Redux, Ionic, JSON Validation
March 2023 - Sept 2023
MatrIoT Solutions, Bangalore
- Developed a BIO DATA web application using Angular for the frontend and Node.js with Express and MongoDB for the backend.
- Implemented CRUD operations, third-party APIs, WebSocket, MQTT, and data validation functionalities.
- Replaced MongoDB with MySQL in the same application.
- Replicated the web application as an Android app using Ionic, a cross-platform framework.
- Updated M3-SUITE web app frontend from Angular 8 to 16 alone.
- Dockerized the above applications.
October 2023 - Feb 2024
MatrIoT Solutions, Bangalore
- Updated the M3-SUITE backend from Node.js version 5 to the latest and replaced MongoDB database with MySQL.
- Mostly worked on Asset Tracker backend while other team members worked on cBin backend.
- Updated the schema model, events, and WebSocket connections.
- Created a Dockerfile for the Node.js application and created Docker Compose for the backend application.
- Worked on one IoT product, creating a logger file using Python and creating a JSON property and validation function.
- Created a WebSocket where two laptop clients and the server can connect and communicate through messages.
April 2024 - Present
SenseGrass, California (Remote)
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Created a fintech app with payment transfer functionality similar to modern Paytm and PhonePe using React Native.
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Included loan and crop insurance functionalities for farmers.
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Integrated payment gateway and payouts using Cashfree.
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Worked on Node.js backend with MongoDB for integrating the Cashfree API.
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Collaborated with 2 developers on this fintech product.
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Developed MoneyPlant app with 2 developers using React Native and Spring Boot PostgreSQL.
- Features include employee loans based on salary, payment transfer, stock investment, mutual funds, SIP, games, gold loans, and credit cards.
- Worked on frontend for onboarding (signup), login, and KYC for new users.
- Developed side navbar, fixed bottom navbar, home screen, and connected screens.
- Implemented QR code scanning and generation, notifications, user profile, game design, and credit card application.
- Worked on the gold loans section.
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Designed the architecture of the entire backend for MoneyPlant using Spring Boot and PostgreSQL.
- Learned Spring Boot and PostgreSQL from scratch while working on the frontend, then started building the backend application.
- Designed model schema for the backend.
- Created APIs for onboarding users, login, and mobile number verification.
- Developed various other APIs for frontend functionalities mentioned above.
