At ERH, we have multiple redundancies built in and treat our puzzles like an airplane. If a player's actions don't trigger the result, we are watching and ready to press the backup switch. What happens if the backup fails? We can run to the room and trigger the switch from outside. If all that fails, we understand our technology well enough that we can force a result, it is not an ideal fix, but better than a puzzle failing. To use an example of forcing a result from a different room, a cell phone had texts that added ambiance and one text contained a clue. The cell phone was dead when we played the room, the game master brought a backup phone with the required text written on a paper note on the screen. It gave us the result we needed, bypassing a failed piece of technology.
Which brings us to the last question, is the technology affordable? I have played some low tech escape rooms that had a lot of heart and passion poured into them, and I enjoyed the experience immensely. To someone new in the hobby, those rooms can potentially feel underwhelming. Having a high tech room can wow players, but it is significantly more expensive and may be out of the budget for some escape rooms. As ERH has grown, we have been able to incorporate more technology behind the scenes to up that wow-factor. Our newest room, Magician's Workshop, really exemplifies this.
At the end of the day, each escape room needs to find technological harmony, a balancing act between budget, vision, and reliability. Most importantly though, it should give the players a unique experience that will inspire wonder and the belief in escape room magic.