Case Studies

We were working on an app, which is a web-based survey and feedback platform developed using Java and the Spring framework and utilizing both PostgreSQL and MongoDB databases. This platform enables users to create, distribute, and analyze surveys to gather valuable insights and feedback.

Technical Use Case:

• utilizing Java for robust backend logic.
• Leveraging the Spring framework for building scalable and modular components.
• Implementing Spring Boot for simplified application setup and development.
• Storing structured data, user information, and survey metadata in PostgreSQL.
• ensuring ACID compliance for transactional integrity.
• Storing unstructured data, survey responses, and dynamic question structures in MongoDB.
• benefiting from MongoDB’s flexibility in handling varying data types.
• Implementing RESTful APIs for communication between the frontend and backend.
• ensuring standardized and stateless communication for scalability.
• employing Spring Security for user authentication and authorization.
• Encrypting sensitive data in transit using HTTPS.
• Implementing proper access controls and data validation to prevent security vulnerabilities.
• designing the application to be horizontally scalable.
• optimizing database queries and employing caching mechanisms for improved performance.
• using messaging systems or Spring Integration for asynchronous processing of tasks like sending survey invitations and collecting responses.
• Leveraging JUnit and Spring Test for thorough unit and integration testing.
• ensuring the reliability and stability of the application through automated testing.
• Implementing logging mechanisms using SLF4J and Logback.
• utilizing monitoring tools like Spring Actuator or custom solutions for tracking application health and performance.

Functional Use Case:

1. Survey Creation:

• Users can create surveys by defining questions, specifying answer types, and setting up survey logic.
• Different question types (multiple-choice, open-ended, etc.) are supported.

2. Survey Distribution:

• Surveys can be distributed via email invitations, public links, or embedded on websites.
• Users have control over survey visibility and accessibility.

3. Response Collection:

• capturing and storing user responses in real-time.
• supporting partial responses and allowing users to save and resume.

4. Survey Analysis:

• providing analytics tools for users to analyze survey results.
• Generating graphical representations of data and trends.

5. User Management:

• user registration, authentication, and authorization.
• managing user profiles and permissions.

6. Dynamic Surveys:

• supporting dynamic surveys with conditional logic based on user responses.

7. Collaboration:

• enabling collaboration by allowing multiple users to work on a survey simultaneously.

8. Reporting:

• Generating customizable and exportable reports for survey analysis.
• offering insights and trends based on survey responses.

9. Notifications:

• Implementing notification systems to inform users about new responses, survey completions, or other relevant events.

10. User-Friendly Interface:

• designing an intuitive and responsive user interface using HTML, CSS, and JavaScript.
• ensuring accessibility for users with diverse needs.

GoPuff is a digital convenience delivery service, and implementing it using React or Vue can be an effective choice for building a responsive and interactive user interface. Below is a technical use case for implementing a GoPuff project using React and Vue:

1. Frontend Framework Selection:

• React or Vue: Choose between React and Vue based on your team’s expertise and preferences. Both frameworks are suitable for building dynamic and responsive user interfaces.

2. User Authentication:

• Implement a secure user authentication system to allow users to create accounts, log in, and manage their profiles. Use JWT (JSON Web Tokens) for secure token-based authentication.

3. Product Catalog:

• Develop a product catalog that displays a variety of convenience items available for delivery.
• Use components to represent individual products, and allow users to filter and search for products based on categories, brands, or keywords.

4. Shopping Cart:

• Implement a shopping cart system that allows users to add, remove, and update items in their cart.
• Use local state or a state management library (such as Redux for React or Vuex for Vue) to manage the cart’s state across different components.

5. Real-time Updates:

• Implement real-time updates for the cart, inventory, and order status using WebSocket or other real-time communication technologies. This ensures users receive instant feedback on their actions.

6. Geolocation and Mapping:

• Integrate geolocation to determine the user’s location and provide a personalized experience.
• Utilize mapping APIs (such as Google Maps or Mapbox) to display the delivery route and estimated time of arrival for the ordered items.

7. Order Placement and Payment:

• Allow users to place orders securely and integrate with payment gateways for online transactions.
• Implement a checkout process that includes an order summary, delivery address, and payment details.

9. Responsive Design:

• Ensure the application is responsive and accessible across various devices, including desktops, tablets, and smartphones.

10. Performance Optimization:

• Optimize the application’s performance by lazy loading components, minimizing unnecessary renders, and optimizing network requests.

11. Testing:

• Implement unit testing and end-to-end testing to ensure the reliability and stability of the application.
• Use testing libraries such as Jest for React or Jest with Vue Test Utils for Vue.

12. Progressive Web App (PWA) Features:

• Implement PWA features to provide an enhanced offline experience and faster load times.

13. Security:

• Ensure the application follows security best practices, including input validation, secure communication, and protection against common web vulnerabilities.

14. Internationalization and Localization:

• Implement support for multiple languages and regions to cater to a diverse user base.
• By leveraging the strengths of React or Vue, you can create a robust and user-friendly GoPuff application that meets the demands of modern convenience delivery services.

The project to which I am assigned is one of the financial projects in MS, which aims to develop a comprehensive and secure financial services platform. Front-end Application: The front-end application is built using HTML, CSS, and JavaScript. It is responsible for handling user interactions and displaying relevant information.

Back-end Application: The back-end application is developed using Java and the Spring Boot framework. It handles business logic and database operations. Employing Node.js for handling asynchronous operations and server-side scripting.

Database: The database used for this project is MongoDB. We used it because we have to store large volumes of financial transaction data.
Message Queue: Amazon SQS uses it to facilitate communication between the front-end and back-end applications.

AWS Services: We used various services, including EC2, RDS, S3, CloudWatch, IAM, AWS SNS, and the Lambda MS project, which adopted a microservices-based architecture to ensure modularity, scalability, and fault isolation. Services include real-time data processing, portfolio management, risk assessment, analytics, and user management. It also integrates with external financial APIs for market data feeds and financial instrument information, which we achieved through RESTful APIs and message brokers. In this case, we had Kafka.
It is deployed on AWS, and we use Elastic Beanstalk, EC2, and Lambda functions.

We also implemented auto-scaling capabilities to handle varying workloads efficiently. As it is a financial application, it needed extra attention to security. So, stringent security measures are implemented to comply with industry standards and regulations. This includes encryption, secure authentication, and data access controls to safeguard sensitive financial information.

AWS CloudWatch and custom monitoring tools are there for real-time monitoring of application performance, resource utilization, and security-related events. The next phase of this project was to implement data analytics tools that would provide insights into user behavior and system performance.

I participated in designing and implementing an online course project project where I used ES6 (ECMAScript 2015) features to improve code quality and performance. This project was more component-based. Here are a few points for the same:
related code snippets
Organize the overall codebase into modular components using ES6 modules. Create separate modules for features like user authentication, course management, video playback, and user profiles. This helps improve code maintainability and allows for lazy loading of modules, improving performance by reducing initial load times.

// userAuthentication.js
import { AuthService } from ‘./authService’;
export function loginUser(username, password) {
// …
}
– Utilize arrow functions for concise, clean, and context-preserving callback functions, especially when handling asynchronous operations or event listeners.

const button = document.getElementById(‘submit-button’);
button.addEventListener(‘click’, () => {
// Handle button click
});
– Use template literals for constructing dynamic strings, such as for generating course titles or user feedback messages.
const courseTitle = `${course.name} – ${course.instructor}`;
– Organize code using classes for encapsulation and inheritance. Create classes for
core entities like user, course, and lesson.

class Course {
constructor(name, instructor) {
this.name = name;
this. instructor = instructor;
}
}
Devtroop.ai
– Implement asynchronous operations, such as fetching course data from a server,
using Promises and Async/Await to improve code readability and handle
Async flows efficiently.

async function fetchCourseData(courseId) {
try {
const response = await fetch(`/courses/${courseId}`);
const data = await response. json();
return data;
} catch (error) {
// Handle errors
}
}
– Destructuring simplified code when working with complex objects, like user profiles
or course details.

const { name, email, avatar} = userProfile;
Use spread operators for merging and copying objects and arrays, which can
improve performance by avoiding unnecessary mutations.

const updatedCourse = {…originalCourse, newContent};
used Webpack to transpile ES6 and ES7 code into older browser-compatible
ES5 code.
– Use type-checking tools like TypeScript or Flow to add type annotations and improve code quality by catching type-related errors early in development.
These ES6 features helped enhance code quality and, when combined with proper optimization and performance best practices (e.g., lazy loading, caching, and minimizing network requests), contribute to the overall performance of the project.