Google Cloud Interview Questions and Answers

Plan for node, zone, and control-plane failures.

• Regional cluster: the control plane is replicated across three zones and nodes spread across zones, so a single zone outage does not take the cluster down. Zonal clusters are cheaper but not zone-resilient.
• Node pools: use multiple node pools for different workloads and enable cluster autoscaling plus node auto-repair and auto-upgrade.
• Workloads: set resource requests and limits, PodDisruptionBudgets, and topology spread constraints so replicas spread across zones.
• Networking: use regional load balancing and multi-cluster ingress or Gateway for cross-region failover.
• Data: use regional persistent disks or a replicated database, and back up with Backup for GKE.

gcloud container clusters create-auto prod \
  --region=us-central1 --release-channel=stable

Test with node drains and zone failures, and watch quota, IP exhaustion, and upgrade windows. Autopilot reduces operational burden but limits node customisation.

Cost in on-demand BigQuery is driven by bytes scanned, so reduce what each query reads.

• Partition tables, usually by date, and add partition filters so only relevant partitions are scanned.
• Cluster on columns used in filters and joins; clustering prunes blocks within partitions.
• Select only the columns you need. BigQuery is columnar, so SELECT * is expensive.
• Use materialised views or scheduled queries to precompute expensive aggregations.
• Avoid correlated subqueries and cartesian joins, and use approximate functions when exact counts are unnecessary.
• Check bytes processed with a dry run before running.

SELECT DATE(ts) AS d, COUNT(*) AS c
FROM `proj.dataset.events`
WHERE ts >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 7 DAY)
GROUP BY d;

For steady heavy usage, consider flat-rate slot reservations and monitor slot utilisation in INFORMATION_SCHEMA.JOBS.