Part A — Cloud / AWS

1. VPS vs EC2
   • What is a Virtual Private Server (VPS) conceptually? How does an AWS EC2 instance relate to or differ from a traditional VPS?
   • What are common operational considerations (networking, storage, scaling, security) when deploying services on EC2?
2. S3 Pre-signed URLs
   • What is an S3 pre-signed URL?
   • Describe a secure flow for client-side uploads (from a browser or mobile app directly to S3) using pre-signed URLs.
   • What aspects should the backend validate or constrain (e.g., object key, content type, size, expiration, bucket policy)?
3. Permissions / IAM Basics
   • Explain the concepts of IAM users, groups, roles, and policies.
   • What is the distinction between identity-based and resource-based policies?
   • Provide an example of granting the minimum necessary permissions for uploading an object to a specific S3 prefix.

Part B — React Fundamentals

1. Explain what React Hooks are and the rationale behind their introduction.
2. Describe the purpose and common use cases for the following hooks:
   • useState
   • useEffect
   • useMemo
   • useCallback
   • useRef
3. What are common pitfalls associated with useEffect dependencies and stale closures, and how can they be mitigated?

Part C — TypeScript Fundamentals

1. Explain the difference between structural typing and nominal typing.
2. Provide a concise example demonstrating TypeScript's type compatibility under structural typing.
3. What common patterns can be used in TypeScript to achieve nominal-like typing behavior?