Intermediate everything in DevOps & Cloud, page 8
Centralized logging across microservices
Ship structured logs from every service into a central searchable store, then propagate a correlation ID through all hops to trace one request.
Distributed tracing for serverless apps
Propagate a trace context through every hop, instrument with OpenTelemetry or X-Ray, capture spans including the database, and correlate traces with structured logs.
Idempotency in event-driven systems
Idempotency means repeated processing yields the same end state; it matters because messages get redelivered; achieve it with idempotency keys and conditional writes.
State machines versus long-running functions
State machines externalize state, pause for human input without running compute, give built-in retries and audit history, and bill per transition.
Running stateful apps with StatefulSets
Stateful apps need stable identity and storage; a StatefulSet gives stable names, ordered rollout, and per-Pod volumes.
Exposing Kubernetes services to the internet
A Service gives stable access and LoadBalancer exposes one service, while Ingress adds L7 host and path routing with TLS for many services.
Multi-stage Docker builds
A build stage compiles with the toolchain, the final stage uses a minimal base and copies only the artifact, cutting size and attack surface.
CI/CD pipeline for a container PaaS
Run tests, build the image, push the tag to a registry, then deploy it to Cloud Run. The registry is the build-to-deploy handoff.
Securely supplying secrets to an app
Never hardcode credentials, inject them as environment variables or pull from a secrets manager, and rotate them.
Data warehouse versus OLTP database
Warehouses use columnar storage for analytical scans, OLTP uses row storage for fast transactions, each fits a different workload.
Strong versus eventual consistency in NoSQL
Strong reads see the latest write at higher latency and cost, eventual reads may be stale but are cheaper and faster, match the choice to stakes.
RDS Multi-AZ versus Read Replicas
Multi-AZ is a synchronous standby for failover, replicas are async for read scaling, combine both when needed.
Shared responsibility model across service tiers
Provider secures the cloud infrastructure; you secure what you put in it; the line shifts with abstraction. For OS patching, you patch IaaS VMs but the provider patches a managed database OS.
Automating a no-public-IP governance rule
Use organization-level policy guardrails (SCP, Azure Policy, Org Policy) to deny public IP attachment before creation, applied across all accounts.
Service-managed vs customer-managed vs BYOK keys
Service-managed keys are automatic but opaque; CMK gives you control over rotation, policy, and revocation in a KMS; BYOK imports your own key material for compliance.
Granting a VM scoped storage access without static keys
Attach a least-privilege role or managed identity to the VM so it gets auto-rotating temporary credentials scoped to the bucket.
CDN caching for static and dynamic content
Cache static assets with long TTLs and versioned filenames; bypass or short-cache dynamic per-user responses; invalidate via fingerprinted URLs not purges.
DNS routing policies for active-passive failover
A failover policy with health checks routes to primary and flips to secondary on failure; keep TTL low; pair with health checks not just policy.
Process running but load balancer says unhealthy
The probe path, port, protocol, or expected status may mismatch; a security group may block the probe; the app may be up but not ready.
Connecting two VPCs privately
VPC peering is simple but non-transitive and full-mesh; a Transit Gateway scales hub-and-spoke; PrivateLink exposes one service narrowly.
We are hiring for this. Every open role lists the topics its interview covers, so you can prepare for the real thing rather than guessing.
See open roles