Interview Q&A / AWS & Cloud

1. What is the difference between RDS and DynamoDB, and when would you use each?

   RDS is a managed relational database service running engines like MySQL or PostgreSQL, with SQL, joins and transactions. DynamoDB is a serverless key-value and document database that gives fast, predictable performance at very large scale if you design around known access patterns. Use RDS for relational data and flexible queries; use DynamoDB for simple, high-volume lookups by key.

   IntermediateIn-depth4 min read
2. How do you choose a good partition key in DynamoDB?

   Pick an attribute with many distinct values that requests spread across evenly, such as user ID or order ID. A key where most traffic hits a few values creates a hot partition that gets throttled.

   IntermediateQuick answer1 min read