Warframe's 'The Steel Path' Hard Mode Outlined
NOT end game

Warframe’s The Steel Path’s Hard Mode was outlined recently on a community post, sharing some information on what exactly it is, and what it’s not.
Basically, if you’ve completed your solar map, you’ll be able to unlock The Steel Path in an upcoming update. The team notes that The Steel Path is a dev workshop at the moment, and just over 1000 players were able top play over this past weekend.
Effectively, this was content of higher difficulty, but rewards you with decorations, emotes, and mastery. It was described as, “an extra layer of opportunity for players,” so they could use their high level gear against high level content, but without having to wait for a while in missions. Finally, it contained better scaling Affinity and Mod Rewards.
As for what The Steel Path hard mod is not, the team makes it very clear that it’s not some sort of end game. They also make it clear that the goals of The Steel path hard mode are quite simple and not overly complex. They just want to provide high level content and rewards. Finally, it is not tiered. There is a single 100+ level pass.
As the post mentioned, look for this in a future update if you’ve cleared your solar map. You can learn more here.