microservices: how to handle inter-service communication latency?

ive been building out a new microservices architecture, and while the benefits are clear, im starting to hit a wall with inter-service communication latency. we're seeing noticeable delays, especially in critical user flows that hop between several services. we're currently using synchronous REST calls, but im wondering if asynchronous patterns or different communication protocols might be a better fit. what are your experiences with managing latency in distributed systems? any patterns or technologies you'd recommend exploring beyond standard REST?