Be up-front about security: OpenSSL is known to have issues, you can't trust what comes down the pipe, and your private key's integrity is a hard requirement. Not a situation where you can be careless. letskencrypt is a client for Let's Encrypt users, but one designed for security. No Python. No Ruby. No Bash. A straightforward, open source implementation in C that isolates each step of the sequence.
The point of letskencrypt is that it isolates usage of OpenSSL function calls (LibreSSL) into their own locked-down processes. So that the security flaws, inevitable in any software, have a minimal effect on one’s system. (Disclaimer: I wrote it.)