GCP Cloud Architect Skill for Claude

GCP Cloud Architect

End-to-end GCP-specific architecture: service selection, Google Cloud Architecture Framework assessment, identity and networking patterns, cost optimization, operational defaults. Provider-specific complement to our generic senior-cloud-architect skill — that one covers cross-cloud patterns; this one knows when to pick Spanner over Cloud SQL, how Workload Identity Federation differs from Service Account keys, and the right Cloud Run vs GKE call.

Core Capabilities

• Compute selection — decision tree across GKE (Autopilot/Standard), Cloud Run, Cloud Functions, Cloud Run Jobs, Batch, Compute Engine, and Vertex AI.
• Data store selection — decision tree across Cloud SQL, Spanner, Firestore, Bigtable, Memorystore, Cloud Storage, and BigQuery.
• Networking — VPC, Private Service Connect, Interconnect/VPN, load-balancer choices, Shared VPC, peering, Cloud Armor, hub-and-spoke.
• Identity — IAM, Service Accounts, Workload Identity (GKE) and Workload Identity Federation, ADC, and least-privilege role/scope binding.
• CAF assessment — score workloads against the five Cloud Architecture Framework pillars.
• Cost optimization — biggest-to-smallest cost levers (right-sizing, CUDs/SUDs, autoscaling, preemptibles, tiering, slots) and cost anti-patterns.
• Workflows — design a new workload, review an existing architecture, and migrate from AWS/Azure to GCP.

When to Use

| Situation | Skill applies |

|-----------|---------------|

| Designing a GCP architecture from scratch | Yes — start with compute decision tree |

| Reviewing an existing GCP architecture | Yes — run CAF assessment via scripts/gcp_caf_scorer.py |

| Validating a Terraform / Deployment Manager plan | Yes — scripts/gcp_architecture_validator.py |

| Estimating GCP cost for a workload | Yes — scripts/gcp_cost_estimator.py |

| Picking between GKE / Cloud Run / Functions / Cloud Run Jobs | Yes — see compute decision tree |

| Setting up IAM / Workload Identity correctly | Yes — see identity reference |

| Designing multi-region / multi-zone resilience | Yes — see reliability reference |

| Picking Cloud SQL vs Spanner vs Firestore vs BigQuery | Yes — see data store decision tree |

| Going to production without CAF review | Don't — run the CAF scorer first |

Clarify First

Before designing or assessing, confirm these inputs. If any is unknown or vague, ASK — do not assume:

• [ ] Task — design from scratch, review an existing architecture, validate IaC, or estimate cost (selects gcp_architecture_validator.py vs gcp_cost_estimator.py vs gcp_caf_scorer.py)
• [ ] Workload spec — the YAML workload config, or the Terraform/Deployment Manager files (the input the scripts parse)
• [ ] Priority pillar — reliability, security, cost, operational excellence, or performance (weights the CAF assessment and which recommendations lead)

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.

Tools

| Tool | Purpose | Command |

|------|---------|---------|

| gcp_architecture_validator.py | Validate a Terraform plan or YAML workload spec for anti-patterns | python scripts/gcp_architecture_validator.py --terraform ./infra/*.tf |

| gcp_cost_estimator.py | Estimate monthly GCP cost from a workload spec, with optimization opportunities | python scripts/gcp_cost_estimator.py --workload-config workload.yaml |

| gcp_caf_scorer.py | Score a workload against the five Cloud Architecture Framework pillars | python scripts/gcp_caf_scorer.py --workload-config workload.yaml |

References

Load the reference that matches the task — keep this file lean and pull detail on demand:

• references/decision-trees.md — the full compute decision tree and the data store decision tree. Read when selecting compute or storage.
• references/networking-and-identity.md — VPC/PSC/Interconnect building blocks, the load-balancer matrix, common networking patterns, and the IAM / Service Account / Workload Identity (Federation) patterns with least-privilege guidance. Read when designing networking or identity.
• references/caf-cost-and-workflows.md — the five CAF pillars, the cost-lever and cost-anti-pattern catalog, all three end-to-end workflows (design/review/migrate), the GCP-specific anti-patterns, and the script tooling-output table. Read when assessing, optimizing, or running a workflow.
• references/gcp-services-reference.md — per-service depth: tiers, SLAs, limits, when to upgrade. Read when sizing a specific service.
• references/gcp-well-architected.md — the 5-pillar CAF assessment with a 10-question checklist per pillar, common findings, and remediation patterns. Read during a CAF review.
• references/gcp-cost-optimization.md — the full cost-lever catalog, anti-patterns, and detection heuristics. Read when driving down spend.

Related skills

• engineering/senior-cloud-architect — generic multi-cloud architecture patterns
• engineering/aws-solution-architect — AWS counterpart
• engineering/azure-cloud-architect — Azure counterpart
• engineering/kubernetes-operator — for GKE operator-pattern workloads
• ra-qm-team/information-security-manager-iso27001 — compliance-mapped controls (GCP has Security Command Center)
• ra-qm-team/soc2-compliance-expert — GCP-specific SOC 2 evidence collection