Short Circuit spam with Netwatch Netdriver or Ultimate rotation with Tetratronic Rippler. The first one is self explanatory. the second one requires legendary hacks and passive cost reduction stacking (so you have to cast your spells in a certain order, making the next one cheaper). It looks like this (ignore the speed boosting, that was patched in 1.5):
Concept is the same both ways. You take the perk "Forget Me Not" and equip Memory Boost cyberware to get +4 RAM on kill. You also take the perk "Daisy Chain" 3/3. Now any enemy that dies under the effect of a quickhack will reduce all your other cooldowns by 50% and give you +4 RAM. If there are enough enemies and you can kill them fast enough, you can get into a self sustaining, infinite spam loop.
Ultimate quickhacks are expensive so you need to stack the cost reduction passive from Legendary Detonate Grenade and Legendary System Reset. Any explosion damage source will stack Detonate Grenade's passive, including thrown grenade kills. Any kill by any means (including all weapon kills) will stack System Reset's passive.
Then you cast your spells in a certain order like Detonate Grenade -> System Reset -> Suicide -> Short Circuit to make the next spell in the sequence really cheap. The order will change depending on what spells are about to reset on kill and what you can afford to cast.
Its better if you mix in weapon kills. You can put all enemies under the effect of a quickhack with Ping, so even shooting people will reset all your spell cooldowns and give you RAM back to cast them. This allows you to go hyper aggro.
It will never be as fast as old Ping/Contagion but that was broken and un-engaging imo. Now you have to deal with resource management and cooldown management. You can't just wallbang everything, get +20 RAM and instant cooldown reset with 1 button. Now you have to actively engage with the combat system. Hybrid hacking/weapon playstyles are more than viable now.
