A cloud engineer is designing a cloud-native, three-tier application. The engineer must adhere to the following security best practices:• Minimal…

Microservices architecture is a design approach where a single application is composed of many loosely coupled and independently deployable smaller services. This design directly meets the requirement for "minimal services," as each microservice is built to perform a single function, thus reducing the attack surface. This architectural style promotes vendor agnosticism because the services are self-contained and can be packaged in containers (e.g., Docker), making them portable across different cloud environments. The use of virtualization is a common underlying infrastructure layer for hosting these containerized microservices.

A. Virtual machine: A virtual machine is a foundational infrastructure component, not an architectural design concept. It can host numerous services, which contradicts the "minimal services" principle.

C. Fan-out: This is a specific messaging pattern used in event-driven architectures to deliver a message to multiple destinations; it is not a comprehensive system design concept that meets all requirements.

D. Cloud-provided managed services: Using these services directly opposes the "vendor agnostic" requirement, as it creates a dependency on a specific cloud provider's proprietary offerings and APIs.

1. National Institute of Standards and Technology (NIST). (2020). Special Publication (SP) 800-204A

Building Secure Microservices-based Applications Using Service-Mesh Architecture. Section 2.1

"Microservices Characteristics

" states that services are "Small in size and focused on a single capability

" which aligns with the minimal services principle. The inherent decoupling facilitates portability.

2. Patterson

D.

& Joseph

A. (2020). CS 162: Operating Systems and System Programming

Lecture 21: Distributed Systems. University of California

Berkeley. Slide 60 discusses microservices as independently deployable components

a key attribute for achieving portability and vendor-agnostic solutions.

3. Lewis

J.

& Fowler

M. (2014). Microservices. martinfowler.com. This foundational document on software architecture

widely cited in academic contexts

explains that microservices are "organized around business capabilities" and are "independently deployable

" which supports the principles of minimal services and portability required by the question.