CDT Architecture & System Design 3 — Questions and Answers
Question 1: A legal firm requires that documents sent externally cannot be forwarded or printed by recipients. Which technology enforces this at the document level?
- Transport Layer Security (TLS)
- Information Rights Management (IRM) (Correct answer)
- Role-based access control (RBAC)
- Network firewall policy
Correct answer: Information Rights Management (IRM)
IRM embeds usage restrictions directly in the document file, enforcing permissions regardless of where the file travels.
Question 2: What is the key advantage of using a microservices architecture for a document processing platform compared to a monolithic design?
- Lower total infrastructure cost in all cases
- Independent scaling and deployment of each processing function (Correct answer)
- Simpler debugging across all document workflows
- Elimination of network latency between components
Correct answer: Independent scaling and deployment of each processing function
Microservices allow each function (OCR, classification, rendering) to scale and be deployed independently based on its own demand.
Question 3: In a multi-tenant document management SaaS platform, which isolation strategy provides the strongest data separation between customers?
- Shared schema with tenant_id column filtering
- Shared database with row-level security policies
- Separate database instance per tenant (Correct answer)
- Single table with encrypted tenant columns
Correct answer: Separate database instance per tenant
Separate database instances provide the strongest isolation because a misconfiguration or breach in one tenant's data cannot affect another.
Question 4: Which caching strategy is most appropriate for a document thumbnail service that generates previews on first request?
- Write-through cache updated on every document save
- Cache-aside (lazy loading) pattern (Correct answer)
- Write-behind cache with async persistence
- Read-through cache with TTL expiry only
Correct answer: Cache-aside (lazy loading) pattern
Cache-aside loads the thumbnail into cache only on the first request, avoiding pre-generating previews for documents that are never viewed.
Question 5: A document workflow system must resume processing exactly where it left off after a server crash. Which design pattern best supports this?
- Fire-and-forget task dispatch
- Stateless REST endpoint design
- Saga pattern with persistent checkpointing (Correct answer)
- In-memory workflow state machine
Correct answer: Saga pattern with persistent checkpointing
The Saga pattern with persistent checkpointing records each completed step so the workflow can resume from the last checkpoint after a failure.
Question 6: In an enterprise document system, what is the purpose of a rendition service?
- Manage user authentication tokens for document access
- Convert source documents into alternative formats or resolutions on demand (Correct answer)
- Index document content for full-text search retrieval
- Synchronize document metadata across distributed nodes
Correct answer: Convert source documents into alternative formats or resolutions on demand
A rendition service transforms the original document into alternate formats (PDF, thumbnail, mobile-optimized) without modifying the source file.
Question 7: Which approach best handles the ingestion of documents with varying schemas and unknown structure in a modern document platform?
- Strict XML schema validation at ingestion gate
- Schema-on-read with flexible document store (Correct answer)
- Relational database with fixed column mapping
- Manual classification queue for all incoming files
Correct answer: Schema-on-read with flexible document store
Schema-on-read stores documents as-is and applies structure interpretation at query time, accommodating diverse and evolving document types.
CDT Architecture & System Design 3
A legal firm requires that documents sent externally cannot be forwarded or printed by recipients.
Which technology enforces this at the document level?