Full-Stack Development Development Sample 5

Question 1

What is the purpose of database migrations in a full-stack application?

Accepted Answer

To version-control schema changes and apply them consistently across environments

Answer

Migrations track schema changes as code, enabling reproducible deployments and rollbacks across development, staging, and production.

Question 2

In async JavaScript, what does the Promise.all() method do when one of the promises rejects?

Accepted Answer

It immediately rejects with the first rejection reason

Answer

Promise.all() uses 'fail-fast' behavior — the moment any promise rejects, the entire call rejects immediately.

Question 3

Which caching strategy serves cached content when available and only contacts the network when the cache is empty or stale?

Accepted Answer

Cache-first (cache falling back to network)

Answer

Cache-first checks the cache first and only fetches from the network if the item is missing or expired, minimizing network requests.

Question 4

What does the 'Single Responsibility Principle' (SRP) state about a module or class?

Accepted Answer

It should have only one reason to change

Answer

SRP holds that a class or module should encapsulate one cohesive concern so that changes to one business rule affect only one unit.

Question 5

In a CI/CD pipeline, what is the purpose of a 'staging' environment?

Accepted Answer

To test changes in a production-like environment before deploying to production

Answer

Staging mirrors production infrastructure so teams can validate behavior under realistic conditions before releasing to real users.

Full-Stack Development Practice Test