CTO Systems Architecture & Infrastructure 3

Question 1

A CTO must choose a networking model for a hybrid cloud environment connecting on-premises data centers to two public clouds. Which approach provides the lowest latency and most consistent bandwidth?

Accepted Answer

Dedicated private interconnects (e.g., AWS Direct Connect, Azure ExpressRoute) to each cloud provider

Answer

Dedicated private interconnects bypass the public internet, offering guaranteed bandwidth SLAs and sub-10ms latency not achievable over VPN or broadband.

Question 2

Which design pattern best prevents cascading failures when a downstream service experiences high latency in a synchronous microservices call chain?

Accepted Answer

Timeout combined with a circuit breaker that opens after a failure threshold

Answer

A circuit breaker stops calls to a degraded service after repeated failures, shedding load and preventing upstream thread exhaustion while the service recovers.

Question 3

An architect proposes a CQRS pattern for a high-read e-commerce catalog. What infrastructure component is most critical to make the read side performant without overloading the write store?

Accepted Answer

An asynchronous event stream (e.g., Kafka) projecting write events to a denormalized read model

Answer

CQRS typically uses an event stream to asynchronously update an optimized read model, decoupling read and write scaling concerns.

Question 4

A CTO evaluates moving from a colocation facility to a hyperscaler. Which Total Cost of Ownership factor is most frequently underestimated in early cloud migration business cases?

Accepted Answer

Egress bandwidth charges for data leaving the cloud provider's network

Answer

Cloud providers charge significant fees for outbound data transfer, which compounds quickly for high-traffic applications and is rarely modeled accurately upfront.

Question 5

When designing a disaster recovery strategy, what metric defines the maximum amount of data an organization can afford to lose, expressed in time?

Accepted Answer

RPO — Recovery Point Objective

Answer

RPO (Recovery Point Objective) specifies the maximum tolerable data loss window, directly determining backup frequency and replication lag limits.

(CTO) Certified Chief Technology Officer Practice Test

(CTO) Certified Chief Technology Officer Practice Test

CTO Systems Architecture & Infrastructure 3