Architecture & System Design Flashcards

When designing disaster recovery for a document repository, what does an RPO (Recovery Point Objective) of 15 minutes require?

Answer: Backups or replication must capture changes at least every 15 minutes

RPO defines the maximum acceptable data loss window; a 15-minute RPO requires that backups or continuous replication run at least that frequently.

A healthcare document system must ensure that patient records are encrypted both at rest and in transit. Which combination achieves this?

Answer: AES-256 for storage and TLS 1.2+ for network transport

AES-256 is the industry standard for encrypting stored data, while TLS 1.2+ secures data moving across networks, satisfying HIPAA encryption requirements.

Which document system design consideration is most critical when planning for a 10x increase in concurrent users?

Answer: Horizontal scalability of stateless application tiers

Horizontally scaling stateless application tiers allows the system to handle more concurrent users by adding nodes without architectural changes.

In a document imaging workflow, what is the function of a document capture server?

Answer: Receive scanned images, apply preprocessing, and route them to the appropriate workflow

A document capture server ingests raw scanned images, applies cleanup (deskew, despeckle, crop), and directs files to downstream classification or indexing workflows.

What is the primary risk of using file system folders as the sole organizational structure in a large-scale document management system?

Answer: Folder structures are rigid and cannot represent multi-dimensional relationships between documents

Folder hierarchies impose a single classification path; documents with multiple attributes or relationships cannot be represented without duplication or complex workarounds.

Which API design pattern is most suitable for real-time document collaboration features like co-editing?

Answer: WebSocket-based bidirectional messaging

WebSockets maintain persistent connections enabling low-latency bidirectional messaging, which is essential for broadcasting cursor positions and edits in real time.

In a document management system, what distinguishes a 'check-out/check-in' model from an optimistic locking model?

Answer: Check-out/check-in prevents concurrent edits by locking the document; optimistic locking allows concurrent edits and resolves conflicts on save

Check-out/check-in enforces pessimistic locking by reserving the document exclusively, while optimistic locking permits parallel edits and detects conflicts at commit time.