A few years ago, I helped a non-profit organization build and deploy a series of web applications and micro-services on top of AWS. One of the services was responsible for sending out email notifications to people via AWS SES.
Back then, I wrote a really simple program in Go that made direct calls to the AWS API. Instead of using an official library, I read the API specification, learned how to authenticate requests, and implemented a fairly trivial SDK. The code was succinct, readable, and worked perfectly for 3 years without any issues.