Go Concurrency, Cross-Language Comparison, Database Trade-offs, and Storage Design

Part A — Concurrency in Go

1. Explain synchronous vs asynchronous execution in Go and how it differs from blocking vs non-blocking I/O.
2. Compare OS threads and goroutines, covering:
   • Scheduler model
   • Stack growth
   • Memory overhead
   • Context-switch cost
   • Communication patterns (channels vs shared memory)
3. Contrast Go's concurrency model with at least one other language (e.g., Java, Python, or C++). Discuss how threads, async/await, and the GIL (if applicable) affect throughput and latency.

Part B — Database Systems

Compare relational, document, columnar, and key–value stores in terms of:

• Data modeling flexibility
• Transactions (ACID vs BASE)
• Indexing and joins
• Scalability via sharding/replication
• Typical use cases

Part C — System Design: Flight Booking Platform

Given a flight-booking platform that supports complex search and high write concurrency, propose an end-to-end storage design. Include:

• Primary database choice and rationale
• Schema or document design
• Caching layer
• Read and write paths
• Justify trade-offs