┌────────────────────────────────────────────────────────────┐
│              Senior Engineering Capstone Portfolio         │
├────────────────────────────────────────────────────────────┤
│ 1. Enterprise Admin & Observability Platform               │
│ (RBAC, Real-time WebSockets, Audit Logs, Data Vis, Sentry) │
├────────────────────────────────────────────────────────────┤
│ 2. High-Scale Production E-Commerce Portal                 │
│ (SSG/ISR, Optimistic Cart, Stripe Checkout, Playwright E2E)│
├────────────────────────────────────────────────────────────┤
│ 3. Real-Time Collaborative Canvas & Document Editor        │
│ (CRDTs / Yjs, Live Presence, Offline IndexedDB Sync)       │
└────────────────────────────────────────────────────────────┘

Authentication (HttpOnly JWT Cookies)
     ↓
Role-Based Access Control (RBAC Permission Directives)
     ↓
Admin Dashboard Layout (Dynamic Nav & Breadcrumbs)
     ↓
High-Performance Data Visualization (ECharts with Canvas rendering)
     ↓
Real-Time Event Stream (WebSockets with automatic reconnection)
     ↓
Immutable Audit Logs & Data Export (Streaming CSV/JSON download)
     ↓
Error Monitoring & Breadcrumbs (Sentry SDK integration)
     ↓
Automated Test Suite (Vitest + Playwright Sharded Matrix)
     ↓
CI/CD Pipeline (GitHub Actions + Turborepo Remote Cache)

// Example: Strict RBAC Permission Directive in Vue / React
export function checkUserPermission(userRole: string, requiredPermission: string): boolean {
  const rolePermissions: Record<string, string[]> = {
    superadmin: ["*"],
    admin: ["users:read", "users:write", "analytics:read", "billing:read"],
    support: ["users:read", "tickets:write"],
    member: ["dashboard:read"],
  };

  const permissions = rolePermissions[userRole] || [];
  return permissions.includes("*") || permissions.includes(requiredPermission);
}

import * as Y from "yjs";
import { WebsocketProvider } from "y-websocket";
import { IndexeddbPersistence } from "y-indexeddb";

export class CollaborativeDocumentSession {
  public doc: Y.Doc;
  public text: Y.Text;
  private wsProvider: WebsocketProvider;
  private idbPersistence: IndexeddbPersistence;

  constructor(roomName: string, docId: string) {
    // 1. Initialize Root CRDT Document
    this.doc = new Y.Doc();
    this.text = this.doc.getText("content");

    // 2. Attach Local-First Offline Persistence
    this.idbPersistence = new IndexeddbPersistence(docId, this.doc);

    // 3. Connect Real-Time WebSocket Provider
    this.wsProvider = new WebsocketProvider(
      "wss://realtime.myenterprise.com",
      roomName,
      this.doc
    );

    // 4. Track Live User Presence & Cursors
    this.wsProvider.awareness.setLocalStateField("user", {
      name: "Alex Engineer",
      color: "#3b82f6",
    });
  }

  public destroy() {
    this.wsProvider.destroy();
    this.idbPersistence.destroy();
    this.doc.destroy();
  }
}

Junior Developer (Asks: "How do I build this?")
       │
       ▼
Mid-Level Engineer (Asks: "How do I build this cleanly using best practices?")
       │
       ▼
Senior Front-End Engineer (Asks: "What is the optimal architecture, what are the trade-offs,
how will this perform under 4x CPU throttling, how will we test it in CI,
how will we secure it against XSS, and how will we know when it breaks in production?")
       │
       ▼
Staff / Principal Engineer (Asks: "How does this architectural decision impact company-wide
velocity, infrastructure cost, multi-team dependencies, and 3-year business strategy?")