[yellowapple]

I've seen enough small businesses with "servers" built from desktops and laptops (and have even been the one doing it, in cases where the one needing it can't justify budgeting for a proper server but does need "something" and is fully aware that I offer nothing even vaguely resembling a warranty) that I'd say it's doable. Yes, it's "bad", but it's a massive money saver and "bad" is better than "nonexistent".

The big risk will be around hardware reliability. A desktop or laptop just ain't built like a server is. Knowing this, redundancy is key. Hell, it's key anyway, but it's even more acute of a need when you're using consumer hardware - especially since your average desktop/laptop won't have redundant power supplies and hot-swappable drive caddies and multiple NICs and all the other goodies that preserve server uptime. Hardware reliability is one of those things that PaaS providers largely abstract away for you, so keep that in mind, too.

My usual strategy for a "poor man's server farm" is to treat entire machines as disposable. Ain't like most laptops have the physical connectors for RAID anyway, and safeguarding data is what backups are for. If any component starts to fail, everything's migrated to a different cheap piece of shit and the old one gets thrown on the "fix it eventually" pile to be either repaired or e-wasted.