Linkerd Cert Monitoring

Hi I recently joined a company who where using linkerd in production. Long story short and due to an issue with linkerd certs werent being renewed by cert-manager which caused a bunch of deployments to fall over after being rotated as they didnt have new certs. Linkerd injection was removed for critical services and I’ve been tasked to look at cert monitoring before we proceed with implementing in production again. Whats the best way to do this? I would like to setup some cert monitors in datadog. thanks.