Because they lack the armour of mainline Cerberus soldiers, the engineers are particularly fragile, possessing low health with only a weak layer of shields on top. Like with other enemies, their shielding will regenerate over time.
Engineers are only dangerous at short range, and their relative fragility makes it easy to eliminate them before they become a threat. However, some of them are equipped with assault rifle and can shoot you while running.
Like other humanoid enemies in the game, Engineers are vulnerable to headshots, receiving bonus damage when shot there.