What would you have done differently in a past project?

The example that I am going to provide is technical one.
Each time we start working on a new project, we build the infrastructure with terraform.
Once the terraform build is successful, we build other higher environments
The files and modules in terraform helps us build environment faster and
it allows us to use the same template for all environments including production
Over time, we add more complexity to the infrastructure and the managing the infrastructure code can become harder

When we add more resources, we sometimes simple copy and paste the existing code while changing the name.
Overtime, we have many duplicates of the similar code
This is bad practice
As the complexity increases, maintaining these code becomes harder

One thing I would have done differently is to plan for complexity
For example, when I create a shared module, I would ask myself how the file structure would look like if I added 100 more lambdas

Overtime, I have learned that we have to plan for complexity within our code as well - not just the infrastructure.
On a later project, we modularied our terraform code so that resource files so that it can be shared
As a lead, I enforce keeping the code dry as much as possible
MANAGING Complexiy

When you keep your code in a way that it can scale, it will prevent messy code and unnecessary band aids