EKS vs AKS

Managed K8s.

Overview

EKS and AKS both run upstream Kubernetes with cloud-specific glue around it. The choice almost always follows the surrounding cloud rather than Kubernetes feature parity. If your data, identity, and networking already live in AWS, run EKS; if they live in Azure, run AKS. Cross-cloud Kubernetes for portability is mostly aspiration.

• EKS. Tight IAM and VPC integration, mature add-on ecosystem (AWS Load Balancer Controller, EBS CSI, Karpenter), control-plane fee per cluster.
• AKS. Native Azure AD integration, free control plane on standard tier, strong Azure-native networking, deeper integration with Azure Monitor.
• Operational fit. Whichever cloud holds your data gravity, identity, and existing IaC patterns wins. Skill-set portability between EKS and AKS is real but lower than the marketing claim.
• Per-cluster decision and exit cost. Workloads are mostly portable; cluster-level glue (IAM, secrets, observability) is the migration tax.

The approach

Pick the cluster on the cloud that already holds the data. Cross-cloud Kubernetes for resilience is a separate (harder) decision than picking a managed-K8s vendor.

• Cloud-gravity check. If your databases, secrets, and identity live on one cloud, the K8s on that cloud wins by default.
• Add-on inventory. List the controllers, CSIs, and operators your workloads depend on; confirm the target managed offering supports each.
• Cost modelling. Control-plane fees, node-group pricing, network egress, and observability charges. The bill across clouds rarely matches the published per-vCPU rate.
• Document the choice and the trigger to revisit. Capture rationale and the conditions (regional gap, regulatory requirement, partnership) that would flip it.

Why this compounds

Choosing one managed K8s per cloud keeps paying back: deploy pipelines, IAM patterns, observability adapters, and on-call muscle memory all anchor on the same flavour.

• Operational consolidation. Fewer K8s flavours means fewer add-on combinations to test, fewer breakage modes for on-call.
• Cost predictability. A documented choice keeps surprise bills out of the next quarter.
• Faster onboarding. One cluster pattern per cloud shortens new-hire ramp.
• Decision trail for the next cluster. Each documented choice teaches the next team which questions to ask, not which cluster to default to.