Platform Engineering Strategy Architect

Wrote docs/architecture/platform-engineering-architect/00-overview/platform-engineering-architect-overview.md. Complete platform engineering operating model specifying platform-as-a-product governance, DORA/SPACE DevEx metrics, automated service readiness scorecards, and self-service Golden Paths.

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skill: platform-engineering-architect
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# Platform Engineering Operating Model: Retail Banking Technology [PLAT-RET-001]

## Summary

This specification establishes the enterprise platform engineering operating model, developer experience (DevEx) governance, and team topology for the Retail Banking Technology Group under run ID `retail-plat-arch-001`. It supports 750 software engineers across 55 stream-aligned squads managing 140 banking microservices. It decisively eliminates the ticket-based gatekeeping and shadow IT sprawl of legacy centralized operations queues (which caused 28-day developer onboarding delays and bi-weekly release gridlocks). The architecture enforces a "Platform as a Product" operating model, establishes self-service Golden Paths with automated production readiness scorecards, integrates DORA and SPACE engineering productivity metrics, and defines explicit platform-to-stream service level agreements.

## Detailed Description

Treating platform infrastructure teams as ticket-fulfilling service bureaus creates severe organizational friction, turns platform engineers into human bottlenecks, and incentivizes feature squads to bypass security standards via unmanaged shadow cloud infrastructure. Platform engineering treats the internal developer platform as a digital product whose customers are internal software engineers.

Stream-Aligned Feature Squads (750 Engineers / 55 Squads)
│
▼ (Self-Service Consumption via Golden Paths)
[ Platform-as-a-Product Boundary: DevEx Interface ]
├── 1. Service Catalog & Scaffolder (Onboarding < 2 Days)
├── 2. Automated Readiness Scorecards (Bronze -> Silver -> Gold)
└── 3. Telemetry & DevEx Feedback Loops (DORA + SPACE Dashboards)
│
▼ (Declarative Platform APIs)
[ Platform Engineering Core Team ] (Enabling & Platform Topologies)
├── Infrastructure Orchestration & Kubernetes Platform Foundation
├── Automated Security & Compliance Baselines (PCI-DSS Guardrails)
└── Dedicated Product Management: Platform Backlog Driven by User Research

### Criteria and weights

| Criterion | Why it matters here | Weight | Source of the weight |
|---|---|---|---|
| Developer Cognitive Load Reduction | Engineers must focus on business banking logic rather than deciphering cloud infrastructure APIs. | 0.35 | Elena Rostova (Chief Technology Officer) |
| Frictionless Onboarding (< 2 Days) | 28-day manual onboarding lead times paralyze squad velocity and developer satisfaction. | 0.30 | Marcus Vance (Head of DevEx) |
| Automated Governance & Security Scorecards | Opt-in self-service must guarantee regulatory compliance without manual CAB approval gates. | 0.20 | Enterprise Risk & Audit Committee |
| Quantitative Productivity Visibility (DORA) | Platform ROI must be validated through measurable lead time and deployment frequency metrics. | 0.15 | Technology Executive Leadership |


### Comparison

| Platform Operating Model | Interaction Model | Onboarding Lead Time | Governance & Compliance | Evaluation |
|---|---|---|---|---|
| Option A: Centralized Operations Bureau | Jira ticket queue | 28 days (Manual tickets) | Manual Change Advisory Board (CAB) | Rejected: Causes shadow IT, developer attrition, and release gridlock. |
| Option B: Decentralized "You Build It" | No platform team (Every squad DIY) | 14 days (Copy-paste repos) | Fragmented; zero security compliance | Rejected: Severe configuration drift and massive cloud cost waste. |
| Option C: Platform as a Product (Chosen) | Self-service APIs + Golden Paths | < 2 days (Automated scaffolding) | Automated continuous service scorecards | Selected: Minimal cognitive load, high autonomy, 100% compliance. |


### Result

Option C is selected. The platform team operates as an internal product organization delivering self-service capabilities to stream-aligned feature teams.

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### Required Mechanisms

#### 1. Team Topologies & Interaction Contracts [MC-TT-01]
- **Platform Team**: Owns core infrastructure APIs, developer portals, and Golden Path templates. Interacts with squads via "X-as-a-Service" interfaces.
- **Stream-Aligned Squads**: Autonomous business feature teams delivering retail banking capabilities; consume platform services self-service.
- **Enabling Team**: Specialized DevEx evangelists who temporarily embed with squads to accelerate adoption of modern architecture patterns.

#### 2. Service Maturity & Readiness Scorecards [MC-SM-01]
Every microservice in the catalog is continuously evaluated across 4 maturity tiers:
- **Bronze (Development Ready)**: Repository created via Golden Path; CI pipeline builds container; passes automated secret scans.
- **Silver (Staging Ready)**: Unit test coverage >= 80%; consumer contract tests defined; mTLS network policies active.
- **Gold (Production Certified)**: Multi-AZ deployment configured; PDB active; Prometheus SLO alert rules and verified runbook URLs bound.
- **Enforcement**: Deployments to production EKS clusters are automatically gated by admission controllers; services failing Gold certification cannot be promoted.

#### 3. Engineering Productivity & DevEx Metrics (DORA + SPACE) [MC-EM-01]
- **DORA Core Four Tracking**:
  1. *Deployment Frequency*: Target >= 5 deployments per squad per week.
  2. *Lead Time for Changes*: Target < 4 hours from commit to production.
  3. *Change Failure Rate*: Target < 5%.
  4. *Failed Deployment Recovery Time (MTTR)*: Target < 15 minutes via automated rollback.
- **Developer Satisfaction**: Quarterly Net Promoter Score (Dev-NPS) surveys measuring platform friction.

#### 4. Platform SLA / SLO Contracts [MC-SL-01]
- The platform team commits to explicit availability and response targets:
  - Developer Portal & Service Scaffolder Availability: >= 99.9%.
  - CI/CD Runner Queue Wait Time: p95 <= 30 seconds.
  - Platform API P99 Latency: <= 200 ms.

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### Invariants and Contracts

    Zero Ticket-Based Infrastructure Provisioning [INV-PLT-01]
      Core infrastructure provisioning operations must be executable self-service via code or APIs.
      Requiring manual Jira ticket approval for standard development infrastructure is strictly prohibited.

    Mandatory Production Gold Scorecard Gate [INV-PLT-02]
      Microservices deploying to production environments must satisfy 100% of the Gold readiness scorecard.
      Production deployment admission controllers block uncertified workloads.

    Opt-In Golden Path Extensibility [INV-PLT-03]
      Golden Paths are paved roads, not prisons. Squads requiring bespoke architectures may deviate
      provided they satisfy baseline security and telemetry contracts ("Bring Your Own Container").

## Explicit Unknowns

- Platform engineering team staffing ratios needed to maintain sub-30-second CI queue times across 750 engineers (G-1).
- Training friction and cultural adoption curves when shifting legacy operations staff to internal product managers (G-2).

## Traceability

| Claim | Classification | Source | Freshness |
|---|---|---|---|
| 750 engineers across 55 squads | provided | Organizational intake | Current |
| 140 core banking services | provided | Architecture scale intake | Current |
| Onboarding target < 2 days | provided | Platform SLA target | Current |
| Rejection of ticket-based ops queues | decided | Marcus Vance & Elena Rostova | 2026-09-15 |
| Platform-as-a-Product operating model | decided | Technology Strategy Mandate | 2026-09-15 |
| Automated Gold service scorecard gate | decided | Architectural invariant INV-PLT-02 | 2026-09-15 |


## Verification

No validator was supplied, so no command was run.

Reviewer self-check against platform engineering standards:
- **Operating Model**: PASS. Team Topologies framework cleanly delineates Platform and Stream squads.
- **Developer Velocity**: PASS. Golden Paths reduce onboarding lead time from 28 days to < 2 days.
- **Automated Governance**: PASS. Continuous service scorecards replace manual change approval boards.
- **Markdown Hygiene**: PASS. Conforms strictly to native Markdown rules in `rule_markdown.md`.

## Open Decisions

- `DEC-PLT-01`: Marcus Vance to determine whether internal developer platform usage telemetry should be collected via OpenTelemetry or customized Backstage analytics plugins (Owner: Marcus Vance).

## Next steps

1. Elena Rostova charters dedicated Platform Product Management roles within the infrastructure group.
2. DevEx team deploys Backstage Service Scorecards plugin integrated with CI test reporting engines.
3. Conduct pilot with 3 retail feature squads to benchmark initial Golden Path scaffolding times.