Over-Engineering — AWS Solutions Architect (SAA-C03)
You added unnecessary complexity — multi-region when single-region suffices, or a managed service when simpler meets requirements.
Simpler solutions score higher when they fully fit
Phrases like "least operational overhead," "simplest solution," and "AWS managed service" are direct scoring signals. Candidates are drawn to architectures that demonstrate depth — Step Functions over EventBridge, custom Lambda layers over native integrations, self-managed Kafka over MSK. When the scenario constraint is operational simplicity, the correct answer is the one that removes the most management burden while still satisfying the requirement. Adding components the scenario does not require is architecture noise, not expertise.
The Scenario
A small business needs a static website with a "Contact Us" form that sends an email. You design CloudFront distribution with Lambda@Edge for URL rewriting, API Gateway REST API with request validation, DynamoDB to store submissions, and SES for email delivery. The correct answer is S3 static hosting with a single Lambda function behind API Gateway that calls SES directly. No database needed — the scenario never mentioned storing submissions, just sending an email. You added 3 services and a database for a use case that needs 2 services and a function.
How to Spot It
- •Count the services in your answer. If you are chaining 5+ services for a problem described in 2 sentences, you are over-engineering. The scenario said "static website with contact form" — that is S3 + Lambda + SES, not a distributed application platform.
- •Lambda@Edge is only needed when you must run logic at CloudFront edge locations (A/B testing, header manipulation, geo-redirects). If the scenario does not mention edge logic, CloudFront Functions or no edge compute at all is sufficient. The exam penalizes using Lambda@Edge when standard CloudFront behavior or CloudFront Functions work.
- •DynamoDB, Aurora, and ElastiCache are only correct when the scenario describes data storage or retrieval requirements. Adding a database "for audit logging" or "just in case" when the question does not ask for it is scope creep.
Decision Rules
Select the compute refactoring target that satisfies both the long-running duration constraint (>15 minutes) and the loose-coupling, reduced-overhead modernization goal — forcing elimination of Lambda on duration grounds and EC2 Auto Scaling on operational-overhead grounds.
Domain Coverage
Difficulty Breakdown
Related Patterns