They would likely make plain, unassuming tech that might look more like a sealed container to our eyes. Manufactured by something with precise automation no doubt, alot of those things would probably be like the equivalent of black boxes in that they perform a function without ever requiring any kind of maintenance or opening them up.
Almost everything they made would be built out of superhard and durable materials, with any vulnerable materials coated in something superhard on a nano scale (a protective patina). Structural failure of materials due to heat or simple kinetic damage would be unheard of. Devices would probably have internal repair contingencies too, able to fix minor faults that could be anticipated. This is the epitome of a throw away culture, but who knows they may have robots specifically designed to deconstruct damaged/broken items and separate all the materials for proper recycling.
They would probably communicate with other devices wirelessly just by proximity. Using a super high compression algorithm (as opposed to encryption) the amount of data necessary to be transmitted could be vastly reduced to the point where the wireless communication could be very low powered (a "noisy" connection with only 1 or 2 bars).
No cables would be required. Wireless energy beaming could be used, in a targeted-beam fashion attributed to a supercomputer pinpointing the location of each device in realtime and aiming the beam at its receiver.
Any weapons technology aliens used would probably be based on utilizing the firepower available from a ship or drone, and targeting it remotely via tunneling electrons. In other words the Phaser the aliens are holding is just a glorified laser designator and it probably doesn't function when a friendly ship/drone isn't within range. This would also allow it to cause Vehicle/Artillery scale damage to whatever they used it on.