CanvasCBL is a full-stack app, with its frontend written in React and Redux, its backend in Go, and its database in Postgres.
When my high school released a new grading system called CBL, they created a complex conversion system into letter grades, for colleges. When I first heard about the converter, it seemed like an algorithm; a process not intended for humans.
So I wrote a calculator. One week after its creation, and with 100 concurrent users, its utility was confirmed, and I continued adding features.
Over the next few months, I continued adding features, including rewriting the entire grade calculation algorithm in Go for speed, allowing you to see your previous grades, a purpose-built mobile view for students, and more.