# =============================================================================
# COMPETENCY RECORD - Cedric Ancellin's demonstrated engineering skills and
# experience. Third-party technologies and vendors are named as the concrete
# skill surface. Professional background / track record.
# =============================================================================

# ============================================================
# SYSTEMS ARCHITECTURE - COMPETENCY RECORD
# ============================================================
# Core Purpose:
#   Demonstrated experience designing the overall shape of a
#   large multi-tenant commerce platform: how requests enter,
#   authenticate, route, execute, and respond - and how the
#   system scales, isolates tenants, and separates environments.
# ============================================================

summary: >
  Designed and built the end-to-end architecture of a large
  hospitality-commerce platform organized around a single
  front-controller request engine, a stateless API tier backed
  by an external session/cache layer, strict multi-environment
  routing, and tenant isolation enforced from the data layer
  upward.


# ==================================================================
# 1. SINGLE FRONT-CONTROLLER REQUEST ENGINE
# ==================================================================

request_engine:
  description: >
    Architected a unified request pipeline where every HTTP
    request (~1,000-line dispatcher) flows through one entry
    point and a strict, ordered lifecycle.
  pipeline:
    - "Edge rewrite of all non-static traffic to a single dispatcher."
    - "Bootstrap of platform primitives (error handling, sanitization, DB, response, security)."
    - "URL decomposition into version / domain / endpoint / format / method segments."
    - "Mandatory-parameter enforcement and global input sanitization."
    - "API-key resolution with auto-detected key type and session load."
    - "CSRF validation for session-type requests (environment-relaxed for non-prod)."
    - "Assembly of a single request-context object threaded through all business logic."
    - "A numbered authorization cascade (folder existence, IP restriction, role gates, tenant access)."
    - "Per-endpoint parameter whitelisting before the handler ever sees input."
    - "Version-aware handler dispatch (path-routing for legacy, method-routing for modern)."
    - "Multi-format response serialization from a single response-builder structure."
  design_wins:
    - "One choke point for auth, sanitization, and audit, no endpoint can bypass it."
    - "Handlers stay thin: they orchestrate a shared business-logic library rather than re-implementing plumbing."
    - "New endpoints are declared as a small, uniform file set (security + routing + handler + parameter docs)."


# ==================================================================
# 2. MULTI-FORMAT RESPONSE CONTRACT
# ==================================================================

response_contract:
  description: >
    Designed a single response-builder abstraction that
    serializes into many wire formats based on a URL path
    segment, with a consistent success/http/message envelope.
  formats: [json, xml, csv, xls, pdf, php-serialized, js]
  features:
    - "Uniform envelope: success flag, HTTP code, message, execution time, data payload."
    - "Automatic content-type negotiation per format."
    - "Optional response-tree trimming for bandwidth-constrained clients."
    - "Reflected-origin CORS with credentialed session support."


# ==================================================================
# 3. STATELESS TIER + EXTERNAL CACHE FOR HORIZONTAL SCALE
# ==================================================================

scalability:
  description: >
    Architected the API tier to be stateless so any node can
    serve any request, with session and hot data pushed to an
    external cache layer.
  mechanisms:
    - "Session context stored in an external cache (with durable fallback rebuild)."
    - "Read/write/analytics database tiers to keep read traffic off the write primary."
    - "Dual-tier response caching (in-memory cache + short-lived file cache) with explicit bypass."
    - "Asynchronous job runners that decouple slow external sync from the request path."
    - "Persistent per-request connection pooling keyed by database code."


# ==================================================================
# 4. MULTI-ENVIRONMENT ARCHITECTURE
# ==================================================================

environments:
  description: >
    Designed a three-axis environment model (server identity,
    logic context, database target) so the same codebase runs
    safely across production, UAT, staging, and hybrid sandbox
    modes.
  axes:
    server_identity: "Physical environment identity set at bootstrap."
    logic_context: "Controls which payment keys, webhooks, and outbound side-effects are live."
    database_target: "Selects the physical datastore, independent of logic context."
  notable:
    - "A hybrid sandbox mode: production logic paths + non-production data + test payment keys."
    - "Environment-aware absolute path resolution so staging code can never write the production store."
    - "Per-developer environment slots with hostname allowlisting."


# ==================================================================
# 5. MULTI-TENANCY
# ==================================================================

multi_tenancy:
  description: >
    Designed tenant isolation as a first-class, hierarchical
    concern spanning system → account → venue → feature scopes.
  mechanisms:
    - "Hierarchical access model resolved into the session context at login."
    - "Per-request authorization checks against the tenant access matrix."
    - "Account-scoped API keys isolating multi-property operators."
    - "Tenant scoping carried all the way into analytics data shares (see COMP-06)."


# ==================================================================
# 6. EXTENSIBILITY & PROTOCOL SURFACES
# ==================================================================

extensibility:
  description: >
    Designed the platform to expose multiple protocol surfaces
    from the same core.
  surfaces:
    - "Versioned REST (v1 / v2 / v4) with independent routing and auth conventions per version."
    - "A GraphQL surface on selected endpoints as a REST alternative."
    - "A Model Context Protocol (MCP) surface that hijacks the dispatcher for AI-tool traffic."
  cross_reference:
    $ref: "https://zc8.com/competencies/02_backend_platform_engineering"