April 1, 2018
OCSP stapling is an improved method for quickly and safely checking the validity of certificates for HTTPS. You can use SSL Labs (e.g. https://www.ssllabs.com/ssltest/analyze.html?d=pantheon.io) and search for "stapling" to see it's enabled. OCSP responses are typically good for about 7 days, so a response will only get updated as its validity lifetime expiration time approaches.