#system-design

Design scalable URL shortening service (like TinyURL). Components: 1. API design (REST/GraphQL). 2. Hashing algorithm (Base62). 3. Database schema (NoSQL vs SQL) and partitioning. 4. Cache layer (Redis) for redirect performance. 5. Unique ID generation (KGS - Key Generation Service). 6. Analytics service (async processing). 7. Rate limiting and abuse prevention. 8. High availability and georedundancy strategy.

Make informed technical architecture decisions for product scalability. Architecture decision process: 1. Define requirements: performance, scalability, compliance needs. 2. Research options: evaluate technologies, frameworks, cloud services. 3. Prototype: build proof-of-concepts for critical decisions. 4. Document trade-offs: benefits, drawbacks, costs of each option. 5. Decision review: technical team consensus on approach. Key decisions: 1. Monolith vs. microservices: start simple, split when needed. 2. Database choice: relational vs. NoSQL based on data structure. 3. Cloud strategy: single vs. multi-cloud, vendor lock-in considerations. 4. API design: REST vs. GraphQL, versioning strategy. 5. Frontend architecture: SPA vs. MPA, framework selection. Documentation: Architecture Decision Records (ADRs) for future reference. Non-functional requirements: security, performance, maintainability, compliance. Technical debt management: plan for refactoring, monitor system health metrics. Balance: current needs vs. future flexibility, time-to-market vs. technical excellence.

Let's do a system design interview. Your task is to design a URL shortening service like TinyURL. Discuss the requirements, API design, data model, and how you would handle scaling the service to millions of users. Draw a high-level architecture diagram.

Compare and contrast the microservices architecture with the monolithic architecture. Discuss the pros and cons of each in terms of development, deployment, scalability, and complexity. For a new, small-scale e-commerce startup, which architecture would you recommend and why?