I need a landscape designer

Need a new backyard! Combination of hardscape & plants. All old landscape has already been removed, so working with raw dirt. A slight slope is involved, roughly 3.5' difference in elevation over a 10' span. See where the railroad ties are in the uploaded picts. Would definitely prefer NOT a regular block retaining wall, open to ideas, surprise me! Recently I fell in love with COR-TEN (or REDCOR) steel use in landscaping, but don't know where/how to utilize it in the design. We have 2 large dogs so minimizing the amount of mud/dirt they bring up onto the deck is important. I envision a small(ish) area of brick pavers around the deck staircase (for the dogs). Also, we will need some type of stairs/landings/platforms leading up to the back service door of garage. In the pictures you'll see an area of direct is already edged, but ignore that as its not the proper size. The existing lilac bush near the railroad ties can either be removed or incorporated into the new design ... I'm not married to it. My husband and I are DIY-ers and have laid block retaining walls, brick walkways, etc. before but this time I'd like a professional design and we will DIY off the plan. One last note ... I'd' like the plants to be low maintenance. Thanks for your help, and please reach out if you have any questions!