You are asked to discuss two system design prompts. For each one, define the users, functional requirements, non-functional requirements, APIs, core workflow, component responsibilities, data model, failure handling, security concerns, and scalability trade-offs. ### Prompt 1: Design a cloud IDE sandbox Design a cloud-based IDE that lets users edit code in a browser and run arbitrary user programs safely in isolated sandboxes. The interviewer is especially interested in the complete workflow and what happens inside the VM or container when user code is executed. Cover at least: - How users create or resume a workspace. - How source files are stored and synchronized. - How code execution requests are scheduled. - How sandbox isolation is enforced. - How stdout, stderr, exit codes, logs, and artifacts are returned to the browser. - How timeouts, CPU limits, memory limits, network restrictions, and malicious code are handled. - How the system scales to many concurrent workspaces. ### Prompt 2: Design a payment processing system Design a backend payment platform that allows a merchant application to charge customers through external payment providers. Cover at least: - Payment creation and confirmation workflow. - Clear responsibilities for each component. - API design for merchants or internal services. - Payment state machine. - Idempotency and duplicate request handling. - Webhook handling from payment providers. - Ledger, reconciliation, refunds, retries, and failure recovery. - Security, compliance, observability, and reliability requirements.