Last year I came across what's known as the 1p Savings Challenge. It's simple: on day 1 you save £0.01, then on day 2 £0.02, day 3 £0.03 and so on, for 365 days. The most you'll ever put aside on a single day is £3.65, but after you're finished you'll have saved £667.95. Pretty impressive.
Remembering to transfer tiny sums of money each day for a full year is, however, more effort than most people will bother with. So, automation of this process seemed like a perfect focus for a small programming project.
Rather than implementing the standard, predictable 1p Savings Challenge, I wanted to add some more interest to the end experience. I decided instead to build an app that would siphon unknown amounts of money from my bank account, in the middle of the night.
After one year, £2,000 would have gone 'missing'. After 5 years, I'd 'lose' £10,000.
To create this app I used Node.js — and worked with Serverless, AWS Lambda, and cron jobs for the first time.
First things first, we need to take a look at the math behind the 1p savings challenge...