I built
https://SSLboard.com to manage your certificates at any scale and see what’s deployed, where and how. It’s using Certificate Transparency to inventory your certificates so it requires minimal input but provides a complete audit of deployed certificates.
Automation isn't enough: qualys.com (famous for SSLLabs.com) is currently serving an expired certificate (expired 8 days ago). They know their job very well, but without a tool to thoroughly and systematically inventory your certificates, you'll miss it.