Build a Self-Service Internal Developer Platform (IDP) with Backstage, Crossplane, GitOps & RBAC

• Backstage portal → one form creates entire micro-service stack.
• Crossplane composes AWS + Kubernetes resources via GitOps.
• Cost & security policies enforced automatically ( OPA ).
• Full audit : who, what, when, how much.

Scope I Will Own (End-to-End)

• Backstage Scaffold Module
  • Custom software template : micro-service-standard ( TypeScript, Helm, IAM, RDS ).
  • Wizard UI : service name, team, cost centre, environment.
  • GitHub integration : opens pull request with Crossplane claims.
• Crossplane Composite Resources (XRs)
  • XRD : CompositeMicroService → RDS Postgres, EKS Namespace, IAM Role, S3 Bucket, Kube ServiceAccount.
  • Composition : multi-region, encrypted, tagged, cost-limited ( max 200 $/month ).
  • Automatic IRSA linkage → pod can assume AWS role.
• GitOps Delivery (Flux v2)
  • Tenant repo : claims live in git → Flux applies continuously.
  • drift detection : kustomize-controller alerts on manual changes.
• Policy & Cost Guardrails (OPA + Kyverno)
  • Kyverno : enforce labels ( cost-centre, owner ) → block non-compliant.
  • OPA Gatekeeper : deny RDS > db.t3.medium if cost-centre = "sandbox".
  • Budget : AWS Budgets auto-created → SNS → Slack when >80 %.
• Developer Portal Plugins
  • TechDocs : Markdown living beside code → auto-published.
  • Cost Insights : Backstage plugin shows monthly spend per service.
    
  • PagerDuty : on-call rotation imported into entity page.
• Audit & Compliance
• CloudTrail → Lake Formation → Athena query : who created what.
• Signed Git commits ( GPG ) + SLSA provenance for platform images.

 Senior Deliverables

• Backstage instance ( Helm ) + custom templates Git repo.
• Crossplane composite definitions + Flux bootstrap repo.
• Policy library ( OPA + Kyverno ) + cost limits Terraform.
• C-level dashboard : lead-time, cost, compliance score.

Why Only a Senior Architect Can Deliver This

• Backstage core maintainer + Crossplane contributor.
• Scaled 2 unicorns to 500+ engineers with IDP; lead-time ↓ 85 %.
• 90-day post-launch continuous improvement ( shared Slack ).