SIA Midterms

System Architecture

The blueprint that defines how components of a system interact to achieve specific goals.

System Components

Includes hardware, software, networks, and data storage.

Hardware

Physical infrastructure: servers, storage devices, networking equipment.

Software

Applications, operating systems, middleware that run on hardware.

Networks

Communication channels connecting components.

Data Storage

Databases, file systems, cloud storage managing information.

Design Principles

Refers to modularity, abstraction, encapsulation, and loose coupling.

Modularity

Breaking a system into independent, self-contained modules that can be developed, tested, and maintained separately.

Abstraction

Hiding complex implementation details and exposing only what's necessary through simple interfaces.

Encapsulation

Bundling data and methods that operate on that data within a single unit, restricting direct access from outside.

Loose Coupling

Minimizing dependencies between components so changes in one component have minimal impact on others.

Scalability

The ability of a system to handle growth (more users, more data, more requests).

Vertical Scaling

Add more power to existing machines (e.g. GPU, RAM, Storage), but is limited to hardware capacity.

Horizontal Scaling

Add more machines (Load balancing, Distributed Systems, Cloud Auto-Scaling), and has virtually no limit.

Flexibility

Ability to adapt to changing requirements such as adding new features, supporting different platforms, and integrating new tech.

Resilience

Ability to withstand and recover from failures such as redundancy, fault tolerance, and graceful degradation.

Architectural Layers

Composed of controller, service, and repository layers.

Controller Layer

Receives HTTP requests, validates input, returns responses.

Service Layer

Business logic lives here. Calls repositories to get/store data.

Repository

Talks to the database. No business logic — pure data access.

Springboot

A convention-over-configuration framework built on top of the Spring ecosystem.

@SpringbootApplication

Typically placed with the main application class.

@Autowired

Used to declare what you need.

@RestController

Used to build RESTFUL web services.

@RequestMapping

Maps web requests to specific methods / classes.

@GetMapping

Used to map HTTP method GET requests.

200

The request is successful and the server has returned the requested data, typically sent after a GET request.

201

The request has been fulfilled, and one or more new resources has been added, typically sent after a POST request.

404

The server is reachable, but the specific page / file is missing.