Meal App Complete Architecture

The following is the complete architecture for our App. We however will most likely not build all of it. Instead, will be building this out incrementally; focusing on the core features of our products first. The feature priorities are:

• [Core] Image Posting
• [Core] User Interaction (Like, Comment)
• Restaurant Integration
• Meal Recommendation
• Calorie Tracking

Architectural Constraints

Nonfunctional Product Characteristics

• Performance is essential for user interactions
• Cost-Effective cause we are broke
• Security

Product Lifetime

• Evolving Architecture: As we are taking an incremental approach in building feature, the software should support the ability to add new modules easily

Software Reuse

• Using 3rd part libraries to speed up development
• Glide for handling Android Image Handling
• Express for handling API Routing

Number of users

• Once a social network starts growing, it tends to experience exponential growth. As such, the software should be elastic
• Software should be scalable with user growth as no one likes a slow social media

Software Compatibility

• No plans for integrating additional software, as such, this isn't important

We have also chosen to go towards a more service-oriented architecture. As such, we'll be adding components and resources as needed during the implementation of a given feature.

Architecture Layers

Architecture Diagram

Description

• Scalability: Using AWS Lambda, we are able to spin up additional concurrent instances of each of our services as demand increases
• Elasticity: Able to modify resource allocation pretty easily on Lambdas
• Database Bottle-neck: Database hosted on Digital Ocean. Both databases need to scale at a constant rate. Also harder to scale up or down as needed. The choice to pick Digital Ocean is mostly a price constraint. Until billing reaches about $30/month, Digital Ocean is a lot more cost-effective than AWS
• Security: All communications are HTTPS; User authentication/authorization layer before being able to access any services. Further authorization layers will be added within each lambda.
• Using Service-Oriented Architecture; Able to easily adapt new modules to the application
• Asset Retrieval: Images are pretty slow to retrieve online. Being an image-centric application, this would create huge performance issues for our users. We are using AWS CloudFront as a CDN to handle content delivery to combat this issue.