Working with microservices introduces a set of operational and coordination challenges that don't exist in a single monolithic codebase, largely stemming from having many independently deployed, communicating components.
Key Points: • Managing communication between numerous small services increases the risk of network latency and makes maintaining data consistency across services significantly harder. • Debugging and troubleshooting become more difficult since an issue can originate in any one of many services, often requiring distributed tracing to pinpoint. • Setting up and maintaining monitoring and logging across every service takes considerably more effort than instrumenting a single application. • Security has to be enforced consistently and individually across every service, since there's no single perimeter protecting the whole system. • Coordinating deployments and managing versioning across many independently evolving services adds operational overhead that a monolith doesn't have.
Example: Tracking down why a checkout request occasionally failed took much longer than in the old monolith because the failure could have originated in the Order, Inventory, or Payment service — only after adding distributed tracing with Zipkin was the root cause (a timeout in the Payment service) quickly identifiable.
Interview Tip: A concise interview answer is:
"The biggest challenges I've faced are debugging across many services, since a single failure can originate several hops away, maintaining data consistency without shared transactions, and the sheer operational overhead of monitoring, securing, and deploying dozens of independent services instead of one. Good observability tooling like distributed tracing makes the biggest difference in managing that complexity."