Trailhead – Platform Developer 1
https://trailhead.salesforce.com/credentials/platformdeveloperi
Links to good architect resources
CTA Trailmix
https://trailhead.salesforce.com/en/users/strailhead/trailmixes/architect-trailmix-master
Trailhead Credentials
https://trailhead.salesforce.com/credentials/technicalarchitect