1. Report Generation ApplicationDesigned and developed spring boot-based application to generate PDF report from complex excel spread sheet. Parsing of the timeseries data from various spreadsheets, transform data and create tables and plots in PDF.• REST APIs for sending spreadsheet and metadata to the backend REST controller service to handle the business logic.• Design of database schema for storing statistically generated data from raw spreadsheet according to business logic.• Implemented business logic to generate well-structured PDF report. The generated report contains multiple tables, plots, and other metadata.• Validated the whole application end-to-end, wrote documentation for the APIs and overall design.2. Fly E-Commerce Mobile Application: Development of WebApp for shopping and event management for B2B and B2C.• Integrating Swagger for API docs and Spring Security for auth.• Designed and implemented a registration system for business owners.• Enabled business owners to select criteria for organizing events or selling products.• Allowing business owners to add and update product details, including images and descriptions, while utilizing PostgreSQL with Spring Data JPA for efficient data management.3. Invoice generation for delivery services:This is an invoicing application for monitoring delivery of the client’s resources. Various delivery personals are enrolled in to the system. At the end of each delivery the delivery personal marks the item delivered and saves digital ack receipts and asks system to generate invoice.• Designed the backend for enrollment flow of the delivery personals. Developed REST APIs to enroll and designed DB schema.• Developed DB schema and REST APIs to monitor list of items picked up by the delivery personals.• Developed a microservice to calculate cost of each delivery for each delivery personal.• Developed REST APIs to generate invoice PDF per day and per month for each delivery personal.