Prometheus is undergoing enhancements to reduce its memory usage and accelerate restart times, as discussed in Ganesh Vernekar's 2020 blog post. Introduced in Prometheus v2.19.0, memory-mapping allows full chunks of the head block to be stored on disk and accessed only when necessary, effectively decreasing memory consumption and speeding up the restart process by avoiding extensive WAL replay. Another ongoing development involves snapshotting in-memory data during shutdown, which, along with memory-mapped chunks, facilitates a quicker recovery of the in-memory state upon startup, bypassing the traditionally slow WAL replay. These features were presented at KubeCon + CloudNativeCon EU, with further updates anticipated as development progresses.