How would you design a metadata service that supports hundreds of billions of files while maintaining low latency and strong data integrity?I would begin by defining consistency, availability, latency, and recovery requirements for each metadata operation. I would use partitioning and replication strategies aligned to access patterns, employ durable write paths and idempotent operations, and build observability around latency, error rates, replication lag, and hot partitions. I would also validate the design through capacity modeling, failure testing, and a staged rollout.
Describe a time you improved the reliability of a large-scale production system.In a strong example, I would explain the original failure modes, the evidence collected from incidents and telemetry, and the reliability targets established. I would then describe the technical changes, such as better isolation, backpressure, retries with bounded behavior, automated remediation, or improved runbooks, and quantify the resulting reduction in incidents or recovery time.
How do you approach performance debugging in a multithreaded or distributed service?I first make the issue measurable and reproducible using traces, profiles, metrics, and controlled load tests. I examine resource saturation, lock contention, queueing, network behavior, storage latency, and inefficient allocation or serialization paths. After validating a likely root cause, I deploy a narrowly scoped fix behind safeguards and monitor both primary performance metrics and possible regressions.
How would you set a technical roadmap for an infrastructure team with competing reliability, scale, and feature needs?I would translate company goals into measurable infrastructure outcomes, such as availability, latency, capacity, cost efficiency, and developer productivity. I would prioritize work by risk, customer impact, dependency criticality, and expected return, while reserving capacity for operational health and urgent incidents. The roadmap would include clear milestones, ownership, architectural decisions, and regular review with stakeholders.
What is your approach to participating in an on-call rotation for critical services?I view on-call as both an operational responsibility and a feedback loop for engineering quality. During incidents, I focus on mitigation, communication, and safe recovery; afterward, I drive blameless analysis and durable corrective actions. I also work to reduce alert noise, improve dashboards and runbooks, and eliminate recurring toil through automation and design improvements.
