You are asked to build a small REST service (in any language/framework you choose) that resembles a minimal Stack Overflow-style Q&A system. Design and implement an HTTP API that supports at least: - Posting a new question (title + body; optionally tags, author) - Querying/searching questions (e.g., by keyword in title/body, optionally by tags) - Fetching a question by id Clarify and decide reasonable defaults for: - Data persistence (in-memory vs database) - Pagination/sorting for queries - Validation and error handling (e.g., missing title/body, invalid id) - Basic non-functional expectations (readability, tests, documentation, how to run) Provide a brief README explaining how to run the service and example requests/responses.