tl;dr:
A Photo Caption Contest API has been successfully built and launched using Node.js, Fastify, and TypeScript. This project demonstrates key backend concepts including user authentication, image management, and caption submission. By implementing basic caching, response times for frequently accessed endpoints were reduced by 30%, showcasing the impact of simple performance optimizations.

You can check out the code here: Github

Context
In the landscape of viral memes and image-driven content, a Photo Caption Contest platform presents an excellent opportunity to apply backend development skills. This project, inspired by the Codecademy "Back-End Engineer" course, serves as a practical application of user interaction, data management, and performance optimization concepts.

Test Setup
The RESTful API built for this project demonstrates several fundamental backend concepts:

1. User Authentication: JWT-based authentication for user registration and login, showcasing secure password hashing and token management.
2. Image Management: Functionality for users to upload images and for the API to serve these images, covering file upload handling and static content serving.
3. Caption Submission: Users can submit captions for images, a feature that involved designing relational database schemas using Prisma ORM with PostgreSQL.
4. Performance Optimization: Node-Cache was used to cache responses for frequently accessed endpoints, demonstrating the significant performance gains possible with even basic caching strategies.

Results
After launching the API and testing it with a Postman collection, several positive outcomes were observed:

1. 30% Faster Response Times: By caching GET requests for images and their captions, response times dropped by 30%. This underscores how basic caching can substantially enhance API performance.
2. Relational Data Handling: Successfully retrieving images with their associated captions validated the effectiveness of the chosen ORM (Prisma) in handling relational data.
3. Authentication Flow: Proper user registration, login, and token-based access to protected routes (like posting images and captions) confirmed the robustness of the authentication and authorization implementation.

One challenge encountered was a slight increase in response time for non-cached requests due to the additional caching logic. However, the performance gain for cached responses more than compensates for this, illustrating the trade-offs inherent in optimization strategies.

Next Steps
This project lays the groundwork for exploring more advanced backend development concepts:

1. API Documentation: Implement Swagger to document the API. This enhances the developer experience for frontend developers or other API consumers by providing clear, interactive API documentation.
2. Advanced Caching: Replace Node-Cache with Redis. This step introduces in-memory data structures and more sophisticated caching strategies, essential for handling increased traffic.
3. Testing: Increase test coverage using Jest. Comprehensive unit and integration testing are crucial for maintaining code quality and facilitating safe, rapid development.
4. Containerization: Dockerize the application. This foray into DevOps teaches how to create reproducible, easy-to-deploy application environments, a valuable skill in modern development workflows.

Thanks
The realization of this project owes much to Codecademy's "Back-End Engineer" course. Its comprehensive modules on Node.js, databases, and API design provided the knowledge foundation necessary to bring this project to life. This hands-on project reinforces theoretical learning and establishes a robust foundation in backend development, paving the way for more complex projects and deeper learning.