Walmart Global Tech Cloud Platforms & Architecture interview questions

Multi-AZ is the answer and the reason matters more than the acronym. Each tier fails differently, and the database is the one where high availability means a failover with a real gap, not zero interruption.

Turns the standard autoscaling definition into the problem it actually causes. Almost every candidate can define an HPA; far fewer can say why theirs did not save them.

A design question with a clear answer at this scale, and the reasoning is what scores. The three options solve different problems and peering and Transit Gateway connect networks while PrivateLink exposes services.

Trace the route and return path before changing rules. First establish whether the failing connection uses IPv4, IPv6 or a private service endpoint.

S3 access failures are rarely about the bucket policy alone. The caller, object ownership and network path determine which authorization checks apply. Start with the failed request and trace changes across those boundaries.

Spreading instances across availability zones is not the same as surviving an AZ failure. What makes the difference is being able to name the four coupling points that quietly re-unify a blast radius you thought you had split.

The services-and-enterprise interview staple. There is a defensible answer and it is not 'always re-platform': the decision is a function of change tolerance, deadline reality and what the workload is worth.

The cheapest storage class is rarely the cheapest answer. Retrieval pricing, minimum durations and per-transition fees decide whether a lifecycle rule saves money or manufactures waste.

A busy date key can throttle while table capacity remains available. Check the actual key distribution and throttling reason before adding capacity or shards.

Fleet-wide replacement is a traffic-shaping problem: bake once, wave through in controlled batches, watch the alarms, and keep the exit open. In-place patching is the alternative and usually the regret.

Hybrid DNS fails in both directions independently. Outbound rules carry VPC queries to your data centre, inbound endpoints bring on-prem queries back here, and both halves need wiring.

Account-per-team is the right instinct, but hand-rolled account setup drifts within a month. Vending turns governance into a pipeline with an SLA instead of a ticket queue.

Guaranteed capacity and discounted capacity are different products. Peak season needs both, arranged in layers and verified with a game day before the traffic arrives.

Data transfer is charged in several unrelated ways and reported as one line, so the first job is decomposition. Most surprises are cross-zone chatter between services that never needed to be on different nodes.

Moving a Kubernetes service account changes its token subject. Separate pod mutation, federation trust and Key Vault authorization before adding permissions.

One is layer 4 and regional, one is layer 7 and regional, one is layer 7 and global. Answer on those two axes and the choice makes itself, including when you need two of them together.

Four levels, and the two that matter operationally are the subscription, where quotas and billing live, and the resource group, which is the unit you delete. Getting the boundaries wrong is expensive to unpick later.

Service principal with a client secret is the answer people give and the one that leaves a credential in a config file. Managed identity is the same object with the secret handled by the platform.

Ask whether Multi-AZ means a DB instance or a DB cluster. One has a non-readable standby; the other has two readers. That distinction decides whether the proposal can relieve the primary.

Two questions settle most of it: how much of the machine do you want to own, and is the workload request-shaped or long-running. Fargate is a way of running containers rather than a competitor to ECS and EKS, which is the distinction people get wrong.

Two structural differences matter more than any service mapping: the VPC is global rather than regional, and permissions are granted to members on resources through a hierarchy rather than attached to identities.