Summary of "Microservices explained - the What, Why and How?"

This video provides a comprehensive overview of Microservices architecture, contrasting it with traditional Monolithic Architecture, and delving into its benefits, challenges, and best practices.

Main Ideas and Concepts:

Monolithic Architecture:
- Definition: A single unit where all application components (e.g., user authentication, shopping cart, product catalog) are part of one codebase.
- Challenges:
  - Difficult coordination among teams due to a large codebase.
  - Inflexibility in scaling; entire application must be scaled even if only one component needs it.
  - Dependency issues with third-party modules (e.g., conflicting versions).
  - Longer release cycles since any change requires rebuilding and redeploying the entire application.
Microservices Architecture:
- Definition: An application is broken down into multiple smaller, independent services that can be developed, deployed, and scaled separately.
- Best Practices:
  - Services should be based on business functionalities (e.g., shopping cart, checkout).
  - Each microservice should perform a single isolated function and be self-contained.
  - Services should communicate through API Calls, Message Brokers, or service meshes.
- Advantages:
  - Independent development and deployment cycles for each service.
  - Flexibility in using different programming languages and technology stacks for different services.
Communication Between Microservices:
- Common methods:
  - API Calls: Synchronous communication where services send HTTP requests to each other.
  - Message Brokers: Asynchronous communication using intermediaries (e.g., RabbitMQ).
  - Service Mesh: External service managing communication logic, often used in Kubernetes environments.
Code Management for Microservices:
- Monorepo (Single Repository):
  - All Microservices are stored in one repository, simplifying development and management.
  - Challenges include potential tight coupling of services and slower performance with large codebases.
- Polyrepo (Multiple Repositories):
  - Each microservice has its own repository, allowing complete isolation.
  - Easier to manage CI/CD pipelines but can complicate cross-service changes and shared resources.
CI/CD Pipelines:
- Importance of CI/CD pipelines in deploying Microservices efficiently.
- Companies like Amazon, Google, and Netflix deploy multiple times a day, showcasing the complexity of these pipelines.
Tools and Technologies:
- Mention of HashiCorp's tools (e.g., Terraform, Vault, Consul) to assist in managing Microservices.
- Kubernetes highlighted as a powerful platform for running Microservices applications.

Methodology and Instructions:

Best Practices for Microservices:
- Structure Microservices around business functionalities.
- Ensure Microservices are independent and self-contained.
- Use appropriate communication methods (API, Message Brokers, service mesh).
Choosing Between Monorepo and Polyrepo:
- Use Monorepo for small projects with few Microservices for simplicity.
- Use Polyrepo for larger projects with dedicated teams for each service to maintain isolation.

Featured Speakers/Sources:

The speaker is not specifically named in the provided subtitles, but they reference HashiCorp and its co-founder and CTO for additional learning resources on related technologies.