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14.17 Classic System Design Problems Applied to This Project ​

This document provides full interview-style system designs applying the architectural building blocks of the 21-BIS-Compliance-Engine to core distributed systems problems.


1. Design This Project at 100x Scale (7,500 RPS) ​

Requirements & Estimation ​

  • Functional: Sub-50ms statutory standard identification and gap analysis for 10 million audits/month; 7,500 peak queries/sec.
  • Non-Functional: 99.99% availability, zero cloud token costs, strict data privacy.
  • Compute Sizing: 7,500 RPS $\times$ 14ms compute $= 105$ dedicated CPU cores. Distributed across 16 Kubernetes nodes (8 cores each).

Architecture Diagram ​

Deep Dive & Bottlenecks ​

  • Embedding Cache: 70% of factory queries target the top 500 mandatory standards (cement, steel, cables). Redis cluster caches the 384-dimensional float arrays for these queries, eliminating ONNX computation for 5,250 of the 7,500 RPS.
  • Index Distribution: Master FAISS index updates are published to S3; pods poll S3 or receive an event hook to atomically reload memory pointers without downtime.

2. Design the Regulatory Gazette Notification System ​

Requirements & Estimation ​

  • Functional: Notify compliance officers via Email, SMS, and WhatsApp when new Quality Control Orders (QCOs) or gazette amendments are published.
  • Volume: 500,000 subscribed manufacturers across India; 5-10 gazettes published monthly.

Architecture Diagram ​

Deep Dive ​

  • Fanout & Deduplication: To avoid spamming, the fanout worker queries subscribed product categories (e.g., users registered for "Civil Engineering & Cement") and enqueues notification payloads with idempotency keys (gazette_id:user_id).

3. Design the Semantic Search System (20,000 Standards) ​

Requirements & Estimation ​

  • Functional: Search over 20,000 national standards with typo tolerance, synonym resolution, and sub-10ms response times.
  • Storage: 20,000 records $\approx 30$ MB FAISS index; 25 MB inverted BM25 text index.

Architecture Diagram ​


4. Design the Factory Certificate & Document Upload System ​

Requirements & Estimation ​

  • Functional: Secure upload of 25MB NABL calibration and factory layout PDFs; automatic OCR verification.
  • Security: Antivirus scanning, cryptographic HMAC signing, presigned URLs.

Architecture Diagram ​


5. Design a Rate Limiter for Regulatory AI Queries ​

Requirements & Estimation ​

  • Functional: Enforce sliding window limits (30 req/min per IP; 500 req/min per enterprise API key).
  • Scale: Sub-millisecond evaluation across 10,000 concurrent IPs.

Architecture Diagram ​


6. Reusing Stack Building Blocks for Classic Applications ​

Classic ProblemHow Our Stack's Components Are Reused
URL ShortenerFastAPI route handling; Base62 encoding; in-memory / Redis key-value lookup returning HTTP 302 redirects.
Chat SystemReact frontend chat stream; FastAPI ASGI WebSocket connections; local intent classifier for bot automation.
News FeedMaster JSON corpus pattern representing feed items; FAISS vector index matching user interest vectors to article embeddings.
Real-Time CollaborationReact state management; FastAPI WebSockets with Redis Pub/Sub backplane broadcasting document edits.