I don't know why this is getting voted into the ground. This advice would seem to be a way to keep motivated while interviewing, keeping sharp through actual coding, and getting up to speed with any changes in general software engineering in the last 4 years. Even if the coding projects go nowhere, motivation is king.
Agreed, but I'd guess it wouldn't get downvotes if it focused just on brushing up skills and making a portfolio piece rather than mentioning revenue and extending runway.
You can't bank on a new project having any significant financial success, or much traction at all really, especially if it's your first rodeo. Making money is mostly about validation, talking to potential customers, and iterating on ideas, not coding. While they are great skills to learn, it's not a particularly efficient way of beefing up an engineering resume.
I do think it's good advice though to build some stuff while interviewing. I'd focus on small projects that can be built and shipped in a month or so, and do a few of these alongside interviews. Also be sure to put effort into nice landing pages--people judge by appearances.
I didn't downvote. But, while working on a side project might well be a good idea to polish up skills, build a portfolio, etc., trying to bootstrap a revenue producing business--assuming that isn't an actual goal--is likely to be a big distraction from both coding and job-hunting.
