The Condrix is at the center of Warframe's Operation Scarlet Spear ground assault mission. You will need to defeat and analyze this huge sentient enemy so that the Codes of Destruction can be broadcast to another squad who will attempt to complete the Murex Raid portion of the event.
The Condrix might be big, but that's not much of a threat in itself. The danger comes from the little Sentients that will accompany it.
When the Condrix first arrives, it will summon other Sentients and continue to do so at the start of each damage phase.
The Condrix will need to be killed in three different stages, but there is little difference between these three stages. The health bar is also closed, you cannot "damage" in a single step, as soon as the Condrix takes enough damage, it will simply become invulnerbal, and the excessive damage will be mitigated.
The Condrix is made of ferrite armor and flesh. Ferrite armor is weak for corrosion and puncture damage, while flesh is weak for virus, toxin, and gash damage. As long as you bring a weapon that deals any of these damage types, you need to be effective against it.
I like to bring a sniper rifle as my primary weapon, especially the Rubico Prime, as it just melts the Condrix.
Small Sentients might be more of a problem for me, as they will adapt to the type of damage you do. Make sure to bring a good mix of damage types across all three of your weapons to counter this.
During each damage phase, take out the small Sentients, then the Condrix will open its giant eye again, allowing you to damage it further.
It's not a particularly difficult or complex fight, just keep an eye out for descaling and go when the Condrix starts to absorb more damage than you can comfortably put out.