Thought I'd ask, maybe this is just as obvious as it seems, or maybe there are some traps.
My project is something I would like to put in an enclosure. As such, there is a ZIF socket, a couple of LEDs, and a switch I would want to be on one side of the board, so they protrude through the cover, but other components, such as a power connector, resistors for the LEDs, would go on the opposite side. No, there would not be any major overlap where the component on one side would obscure the pins of the component on the other side. Or I suppose I could just make 2 boards and connect them together, there's nothing high speed that would cause problems with a few wires joining the two boards - maybe that's the easiest approach. Hmm, just thinking out loud typing this makes me realize putting parts on both sides is probably not the best way to handle this.
There is no reason why you can't put parts on both sides of the board.
If you were having the boards assembled by a contract manufacturer, you should consult with them to see if they have any caveats, preferences or show-stoppers. But my guess is that this is something you'll build yourself.
This is just a one-off for myself. It's simple enough to just point to point wire, but I thought it might be good practice to lay out a board and have one made.
Putting parts on both sides is perfectly fine.
The only reason, that i know, why i have to avoid putting components on both sides at work, is that additional costs when a supplier has to manufacter the whole board. So i think it's absolutly fine.
When a board includes both SMD and thru hole components it can present challenges if they are mounted on both sides. Either selective fountain soldering, glue, or PIP are used but they all have limitations/downsides.