As you progress throughout the game, you will unlock AVP Status Controller, allowing you to release different types of Cryo Pods to benefit your game with things such as extra minerals collected etcetera. As you increase the Nexus level through viability, you'll unlock more pods to use.
Eventually, under science, you'll get the opportunity to unlock the Innovation pod. Unlock, go to research, make your weapon of choice (I used an AR) and then go to development. Develop the weapon, and before you craft you'll have the option of adding mods to your gun. Simply assign at least three mods to the nodes and confirm your crafting development. The achievement will then pop for you.
Note: this also works for armor. If you want armor instead of a gun just follow the same steps as above and replace the word gun with armor. Happy hunting!