Transit wants AWS designs that keep working when a single component fails. Which Well-Architected pillar most directly covers that requirement?
Select an answer to reveal the explanation.
Short Explanation
Keeping the buses running when one engine stalls is reliability, not "go faster." Reliability is the pillar about withstanding and recovering from failures so the workload stays available. Performance Efficiency is about resource fit and scaling for efficiency; Cost and Sustainability chase spend and environmental impact.
Full Explanation
Reliability includes designing for failure, using isolation and redundancy where appropriate, and recovering automatically from disruptions so the workload continues to meet availability goals. Performance Efficiency addresses selecting and scaling resources to meet performance needs efficiently, which is not the same as fault tolerance. Cost Optimization and Sustainability address economic and environmental concerns. Transit’s requirement that the design keep working when a single component fails maps to Reliability.