Hello, I have 2 years of experience in scripting google sheets and i can help you with your projects, I can't share a portfolio as most of my projects are confidential but i can give you some short descriptions for some of the projects I've worked on:
-A script to batch update a firestore database from gs
-an elimination brackets tournament using gs and scripts
-campagain builder
-FBA amazon organic ranking
-invoice generator (saving files in drives as pdfs and other formats using scripts)
-google apis like places api to get location data
-some minor scripting projects
Ideally, for small or medium projects i finish new requirements in the same/next day, i receive payment only after delivering the requirement.
for big projects we set the deliverables and deadline prior to the contract and i finish on time, payment can be at the end of the projects or by milestones depending on the project nature.
any bugs that appear after delivery are fixed for free as long as they are caused by a feature i was working on (anything that doesn't include adding new features is fixed for free).
looking forward to hearing from you soon and working for you.