when does a monolithic app get too big to handle, like, when do you know its just gotten too unwieldy

hey folks, i'm working on a project where the monolith is getting pretty hefty. we're hitting some performance bottlenecks and deployment cycles are getting longer. it feels like we're approaching a tipping point. when have you all found yourselves needing to break apart a monolith? what were the key indicators that it was time to start thinking about microservices or a different architecture? curious to hear your experiences and what strategies worked for you