TL;DR Monoliths have lower latency  (nanoseconds for internal calls vs milliseconds for network calls). Microservices add 10-100ms per request chain. Microservices scale granularly  – scale only services that need it. Monoliths replicate everything together. Use gRPC for efficient binary communication , batch operations to reduce call count, and circuit breakers to prevent cascading failures. Start with a modular monolith  unless you need independent team deployment or dramatically different scaling per service. Architecture choice significantly affects performance characteristics. Monolithic applications have different bottlenecks, optimization strategies, and scaling patterns than microservices. Neither approach is universally superior; each suits different contexts. Understanding performance implications helps choose and optimize the right architecture. Performance Characteristics of Each Approach Monolithic applications run as single processes. All components share memory space.…