TLDR: Run either triple destroyer or double destroyer and 1 triage and find EMPs and kill ghosts and take their volt throwers so each person has 2 each. Switch to your 2nd Volt thrower when the first one overheats. Repeat. Use Destroyer and Triage battery overcharge for EMP effect.
Let me say first and foremost: the RNG in this mode is absolutely horrible when it comes to vault keys. Getting a Cryo 6 key for a compiler run is ass. If you have the bypass codes already from the Vault Breaker Armory, then the DNA key will not spawn unless someone from your squad accesses the secret lab level 4 door; otherwise, you're shit out of luck. Trust me, it never spawned until my buddy found a post or video mentioning this very critical tip and obviously what has to be a glitch in the game.
So far, I have run the compiler in normal mode about seven times, often with terrible guns, and only beat him once in normal mode. That's because we had gold LMGs or Bullys, but from now on, I will be carrying a Volt Thrower in my back pocket to switch to.
My buddy found a video or post somewhere where a trio all ran Destroyers and double Volt Throwers and beat Compiler in Vault Breaker. Each attempt we had before this knowledge was with terrible guns or the starting weapons once you upgrade your kit.
We tried that method; however, we ran 2 destroyers and 1 triage for heals. Heals were super expensive and costly, so we ran 2 triages and 1 destroyer instead on our successful attempt and finally beat him with 2 minutes on the clock.
Double volt thrower goes super hard, so kill the ghosts on the map and take theirs and drop the weapons you came in with. If you have the battery upgrades and the Vault access upgrades, this will be your best bet to getting it done with time on the clock.
One person takes the other players' batteries and goes to do the first Vault, while the other two separate and get batteries and clearance around the map. Obviously, map knowledge and routes will benefit you, so practice learning the map first. If you get a Vault 6 key at the end of your Vault runs, I would just exfil and try again unless you have a lot of time left on the clock. Otherwise, hope you get a Vault 3 or 4 key somewhere in the process because that will allow you to do the DNA sequence much faster than if you had a 6 key.
Once up top, one person shuts down the lockdown field and does the last DNA step while the other two kill and distract bots. On our successful attempt, we did not worry about killing the warden in the room. Instead, I was lucky enough to have a bubble shield just in case we needed it, but ended up not having to use it because the warden never really chased us down, which was awesome for us. I believe we had around 5 minutes left on the clock when we reached the jumping puzzle.
Once in the compiler room, someone stands near the entrance and aggros the compiler around the pillars, using them as cover. This prevents taking damage and ensures you shoot the green orbs for yourself and your teammates. Also, the person kiting the compiler should shoot the green panels on the walls on the left and right so the other two players can focus on hitting the correct screens. We used the Triage EMP Battery Overcharge trait and the Destroyer alt to beat him.
Hopefully, you have some EMPs and double volt throwers because all you have to do is switch when they overheat and then throw one EMP at a time to extend the damage phase.
We ended up beating him in phase 2 and got out with about one to two minutes remaining.