Cache Warming: Should you do it ahead of time or wait and see?

hey everyone, ive been thinking about cache performance lately. we're seeing some latency spikes right after deployments or when traffic suddenly spikes, probably cuz the cache is cold. weve talked about invalidation and different cache types, but im curious about proactive cache warming. do you guys implement strategies to pre-populate caches before theyre actually needed? what methods have you found effective? or do you rely more on reactive approaches like on-demand fetching and accepting the initial latency hit? looking forward to hearing your experiences.