Final exam

Assigning one class variable to another normally copies what?

1. A deep copy of every field
2. The entire object
3. A reference to the same object
4. A new immutable record

Which statement about .NET garbage collection is correct?

1. It closes every file immediately when a method returns
2. It reclaims unreachable managed objects; resource cleanup still needs explicit lifetime handling
3. It makes IDisposable unnecessary
4. It prevents all memory leaks

What is the main scalability benefit of async I/O in ASP.NET Core?

1. It avoids holding a thread while awaiting I/O
2. It makes DbContext thread-safe
3. It makes each database query use more CPU cores
4. It removes network latency

An EF query calls ToList before applying a filter. What is the likely consequence?

1. Rows are materialized first and the later filter runs in memory
2. An index is automatically added
3. The filter is guaranteed to run in SQL
4. Deferred execution continues unchanged

Which feature is part of C# 14?

1. System.Threading.Lock was first introduced
2. Primary constructors were first introduced
3. Extension blocks supporting extension properties and static extension members
4. async and await were first introduced

Which middleware relationship is required when protecting an endpoint with user policies?

1. Exception handling must run after every endpoint has completed
2. Authentication establishes identity before authorization evaluates access
3. CORS replaces authentication
4. Authorization should establish the user before authentication

An operation is accepted for background processing but not finished. Which response fits?

1. 204 proving the job completed
2. 301 to mean processing failed
3. 401 to mean queued
4. 202 Accepted with a way to check status

Which is usually appropriate for an EF Core query returning entities only for display?

1. AsNoTracking when updates are not intended
2. SaveChanges after every row read
3. A singleton DbContext
4. Parallel queries on one context

What is a normal trade-off of adding a database index?

1. Some reads improve, but storage and write maintenance increase
2. Transactions stop being necessary
3. All writes become free
4. Every query uses it automatically

What should primarily guide a NoSQL document model?

1. Choosing the newest product
2. Avoiding all duplicate data at any cost
3. Copying relational tables exactly
4. Access patterns, consistency needs, document growth and update boundaries

Two buyers can read the same stock value before either writes. What protects the invariant?

1. A read replica
2. An atomic conditional update or suitable transaction/concurrency control
3. A longer cache TTL
4. A browser check alone

In relational algebra, which operation selects rows matching a predicate?

1. Selection σ
2. Cartesian product ×
3. Projection π
4. Union ∪ regardless of predicates

Why might a modular monolith be a reasonable starting architecture?

1. It requires every module to share all internals
2. It can preserve clear boundaries with simpler deployment and local transactions
3. It guarantees unlimited scale
4. It eliminates all module boundaries

Which pattern fits interchangeable payment-calculation algorithms behind one contract?

1. Observer for replacing every method call
2. Prototype for database transactions
3. Strategy, when actual algorithm variation exists
4. Singleton solely because algorithms exist

What is the safest approach to a refactor intended to preserve behavior?

1. Change requirements and structure together without noting it
2. Assume cleaner-looking code is equivalent
3. Use small steps with relevant behavior checks
4. Rename every file first

What does a transactional outbox persist atomically with a business change?

1. A global transaction across HTTP services
2. The intent to publish an event
3. A guarantee no consumer can fail
4. The remote provider's entire database

What is a cache stampede?

1. A database transaction rollback
2. A CDN changing HTTP versions
3. A cache hit with zero latency
4. Many requests rebuilding the same expired or missing value simultaneously

A JWT is valid, but the requested order belongs to someone else. What is needed?

1. Only HTTPS
2. Only CORS
3. Resource-level authorization for the authenticated user
4. Only a stronger signing algorithm

What most directly links spans across services in a distributed trace?

1. Setting all logs to Error
2. Using the same log filename
3. Propagation of trace context such as traceparent
4. Removing request identifiers

Which test best checks provider-specific transaction and SQL behavior?

1. A test of private helper names
2. An integration test against the actual database engine
3. A formatter check
4. A mock returning a fixed list

What helps a rolling deployment tolerate old and new application instances together?

1. Running unreviewed destructive migrations on every startup
2. Disabling readiness checks
3. Dropping required columns before deploying code
4. Backward-compatible expand-and-contract schema changes

What remains your responsibility when using a managed cloud database?

1. Installing the database engine's patches and replacing failed physical disks
2. Nothing related to security
3. Only setting database firewall rules; application identity and permissions are handled automatically
4. Data access, configuration, application correctness and verifying recovery requirements

What does TLS primarily protect for an HTTPS connection?

1. Correctness of every business calculation
2. Authorization to every order
3. All data after it is decrypted and logged
4. Confidentiality and integrity in transit, with server authentication when validated

What do threads in one process generally share?

1. No memory at all
2. The exact same stack
3. A separate operating-system process per method
4. The process address space, while each thread has its own stack

What is the purpose of an anti-corruption layer around a legacy integration?

1. To copy legacy terminology throughout the domain
2. To translate external contracts and isolate their assumptions
3. To eliminate the need to test mappings
4. To guarantee the legacy service never fails

Which is a useful acceptance criterion?

1. A repeated cancellation returns the same successful outcome without releasing stock twice
2. Apply a familiar design pattern without checking whether it fits
3. Create many interfaces
4. Use a newer framework version even if behavior changes

What is the usual average lookup complexity of a well-distributed hash table?

1. O(1) in every case, including identical hash codes
2. O(n) even when the hash table is well distributed
3. O(1), with worse cases still possible
4. Always O(log n) with no assumptions

Why does the standard two-pointer pair-sum technique require sorted input?

1. It makes the array immutable
2. Moving a pointer then changes the candidate sum in a predictable direction
3. It makes all pairs unique automatically
4. It removes integer overflow

Where must authorization constrain a RAG answer?

1. After drafting the answer but before returning it to the caller
2. During retrieval before unauthorized text reaches context
3. Only in a request asking the model to hide forbidden data
4. Through response filtering without checking retrieved source permissions

What is the strongest review basis for an AI-generated change?

1. A detailed explanation of the change from the model
2. Only a successful formatter run
3. Acceptance criteria, an inspected diff and independent relevant verification
4. A clean build without reviewing behavior or the diff

What is a limitation of autoscaling stateless APIs?

1. It removes downstream rate limits
2. It can increase load on a database that remains the bottleneck
3. It automatically shards all tables
4. It guarantees instant scaling with no warm-up

Which behavioral answer is strongest?

1. A story copied from another engineer
2. A real event with clear responsibility, actions, outcome and learning
3. A claim that teammates caused every problem
4. A list of adjectives with no example

Which type is usually appropriate for decimal currency calculations?

1. string for every arithmetic operation
2. double because 0.1 is exactly representable in binary
3. float because fewer bytes always means better accuracy
4. decimal with explicit currency and rounding rules

Can two EF Core queries safely run concurrently on the same DbContext?

1. Yes, if wrapped in Task.Run
2. Yes, if both are async
3. No; use separate contexts or execute them sequentially
4. Yes, if AsNoTracking is used

An idempotency key is reused with a different payment payload. What should happen?

1. Return an unrelated customer's result
2. Ignore the key whenever the amount changes
3. Reject the conflicting reuse according to the API contract
4. Silently perform the second charge

Which change fixes SQL injection from interpolated values passed to FromSqlRaw?

1. Catch Exception and return an empty list
2. Escape quote characters manually before concatenating values into SQL
3. Wrap the interpolated SQL in a transaction
4. Use a parameterizing API or explicit SQL parameters

A client request times out during an external charge. Which conclusion is valid?

1. The outcome may be unknown and needs idempotency and reconciliation
2. A second charge without a key is always safe
3. The database rollback refunded the charge
4. The provider definitely did nothing

Which approach is appropriate for public observability data?

1. Use successful HTTP status as proof every answer is correct
2. Remove all correlation IDs
3. Log every token, password and customer message by default
4. Capture useful structured context while redacting secrets and limiting sensitive retention

What does valid JSON Schema output from an LLM still require?

1. Business validation, evidence checks and authorization for actions
2. Acceptance of every generated citation
3. No further checks
4. Automatic permission to call every tool

A singleton captures a scoped DbContext. Which review finding is correct?

1. It is a captive dependency; align lifetimes or create a scope per operation
2. It is safe if the model generated it
3. Only add ConfigureAwait(false)
4. Make the context static to fix the lifetime