Microservices communicate synchronously via REST/gRPC where the caller waits for a response, or asynchronously via messaging/events where services publish and consume messages. Sync is simple but tightly couples services and propagates failures; async improves resilience but adds eventual consistency and complexity.
Advanced answer
Deep dive
Expanding on the short answer — what usually matters in practice:
Explain the "why", not just the "what" (intuition + consequences).
Trade-offs: what you gain/lose (time, memory, complexity, risk).
Edge cases: empty inputs, large inputs, invalid inputs, concurrency.
Examples
A tiny example (an explanation template):
// Example: discuss trade-offs for "how-do-microservices-communicate?-synchronous-vs"
function explain() {
// Start from the core idea:
// Synchronous communication uses HTTP/REST or gRPC and is simple but tightly couples service
}
Common pitfalls
Too generic: no concrete trade-offs or examples.
Mixing average-case and worst-case (e.g., complexity).