Yet another self serve DSP? It's not as if there are not enough already. Solutions that are designend and purposely built for performance marketers (aka: direct-response marketers) are not in great supply.

The ones that do exist are clunky at best, and have extremely high mark-ups, commonly referred to as \ad-tech tax\. A basic rate is 20%. Some are even charging more in the back-end out of sight of the buyers.
The programmatic industry has needed a better RTB solution for performance. Until now self-serve DSP's have been built by engineers, not media buyers that are looking for performance. And teh UX has been primarily for brands adn the biggest agencies just looking to buy CPM or fixed rate traffic.
Once you are dealing with \performance\ it soon becomes very difficult to mould and iterate campaigns to optimise target CPA or CPI's. Advance marketers have always required OpenRTB integration and tracking API's. And this has been the trade-off: good self-serve UI and no API, or API and terrible back-end so you end up building your virtual DSP.
Meanwhile campaigns are waiting and floundering.
Surely there is a solution.