The Pillars of the AWS Well-Architected Framework are a great way to think about building solutions on AWS. The first pillar, Operational Excellence, sets the tone and if done right enhances your success with the rest of the pillars.
Be Agile
Use an Agile software development process. This allows you to quickly react to new priorities without breaking things, leading to faster time to market without compromising your customer experience. There is no one size fits all. The best process is the one that is optimized for your application domain and the size and skills of your team.
Automate
Adopt a continuous integration/delivery (CI/CD) practice using automation tools. This enables regular code merging to catch bugs early and eliminates human error in the build and deployment process, saving cost and reducing time to market.
Infrastructure As Code
Embrace Infrastructure as Code (IaC). Managing AWS resources can be time consuming and error prone when done manually. CDK and CloudFormation allow developers to be more productive while maintaining AWS resources in a secure and reliable manner.