The certificates Let's Encrypt issues are _not_ self-signed. They are signed by a trusted certificate authority which Let's Encrypt manages, and are no differen

The certificates Let's Encrypt issues are _not_ self-signed. They are signed by a trusted certificate authority which Let's Encrypt manages, and are no different from domain validated certs signed by any other CA. That article makes the mistake of assuming that if a certificate is free then it _must_ be self-signed, which is obviously false.