Full-Stack Development Technology & Digital Applications 3 — Questions and Answers
Question 1: What is the difference between SQL and NoSQL databases in terms of schema?
- SQL is schemaless; NoSQL requires a fixed schema
- SQL enforces a fixed schema; NoSQL typically allows flexible or schemaless storage (Correct answer)
- Both require predefined schemas enforced at the application layer
- NoSQL enforces stricter schemas than SQL
Correct answer: SQL enforces a fixed schema; NoSQL typically allows flexible or schemaless storage
Relational SQL databases require a predefined schema with typed columns, while most NoSQL databases allow documents or records to have varying fields.
Question 2: Which authentication mechanism uses a signed, self-contained token to transmit user claims between client and server without server-side session storage?
- OAuth 2.0 authorization code flow
- Session cookies with server-side store
- JSON Web Token (JWT) (Correct answer)
- SAML assertions
Correct answer: JSON Web Token (JWT)
JWTs are digitally signed tokens encoding claims that the server can verify without a database lookup, enabling stateless authentication.
Question 3: In CI/CD pipelines, what distinguishes continuous delivery from continuous deployment?
- Continuous delivery automates testing only; continuous deployment also automates the build
- Continuous delivery requires manual approval before production release; continuous deployment releases automatically (Correct answer)
- They are identical terms used interchangeably
- Continuous deployment skips automated tests to release faster
Correct answer: Continuous delivery requires manual approval before production release; continuous deployment releases automatically
Continuous delivery ensures code is always release-ready but requires a human gate; continuous deployment pushes every passing build to production automatically.
Question 4: What is the primary advantage of using GraphQL over a traditional REST API?
- GraphQL is always faster because it uses binary encoding
- Clients can request exactly the fields they need, avoiding over-fetching or under-fetching (Correct answer)
- GraphQL eliminates the need for a backend server
- GraphQL automatically generates database schemas
Correct answer: Clients can request exactly the fields they need, avoiding over-fetching or under-fetching
GraphQL lets clients specify precisely which fields to return in a single query, reducing unnecessary data transfer compared to fixed REST endpoints.
Question 5: Which browser storage mechanism is best suited for storing large amounts of structured data client-side with querying capabilities?
- localStorage
- sessionStorage
- Cookies
- IndexedDB (Correct answer)
Correct answer: IndexedDB
IndexedDB is a low-level browser API providing a transactional database for large amounts of structured data, including files and blobs.
Question 6: In microservices architecture, what pattern is used to maintain data consistency across services without distributed transactions?
- Two-phase commit (2PC)
- Saga pattern (Correct answer)
- ACID transactions
- Monolithic coupling
Correct answer: Saga pattern
The Saga pattern breaks a transaction into a sequence of local transactions, each publishing events that trigger the next step or a compensating rollback.
Question 7: What is tree-shaking in the context of modern JavaScript bundlers?
- Recursively traversing the DOM to remove unused elements
- Eliminating dead code (unused exports) from the final bundle at build time (Correct answer)
- Shaking out race conditions in asynchronous code
- Restructuring the component tree for better rendering performance
Correct answer: Eliminating dead code (unused exports) from the final bundle at build time
Tree-shaking statically analyzes ES module imports and removes any exported code that is never imported, reducing bundle size.
Full-Stack Development Technology & Digital Applications 3
What is the difference between SQL and NoSQL databases in terms of schema?