If you have the money you could put in terraces, fill with good soil, and do nice plantings that you give you something really pretty to look at.

Terraces are one option ... an expensive one. Slope is an acceptable way to deal with elevation change -- a cheaper one -- and it looks like that's the option the developer chose. Usually, in order to be stabile, slopes need plant cover ... as in groundcover. That would be the minimum solution. You didn't give us a view that showed what you see beyond the slope, but if there is anything unsightly, or just plain boring, you could also add some type of tree form plants to the slope. It could be a few, or a couple of rows. It depends on what the overall space is calling for, and we can't see that. Possibly, at the back or ends of the view (slope) you might want some shrubs or a large patch of perennials that contrast with the groundcover.

Or is there a spectacular view from the crest, in which case it would be worth creating a path to reach it. If not, think of it like a canvas to paint with the lowest maintenance plant material that works in your conditions. Have you looked at other examples and learned what appeals to you? I remember being blown away by the beauty of hillsides along the highways of California. They might provide good ideas!

Making it look pretty will be a big job...making it look green is as easy as space planting St.John’s wart and water it until it begins to spread ...with occasional watering it will be solid fluffy green in a year...looking much like the green hill in the first pic posted in previous comment

Look for native ground covers. If you include your zone or general area (such as Bay Area or San Joaquin Valley), you may get some specific suggestions. Mexican evening primrose (pink) will thrive in some areas, enough to be invasive if fed and watered occasionally. https://www.wildflower.org/plants/result.php?id_plant=oesp2

More ideas at https://www.laspilitas.com/garden/groundcover_one_foot.html

It will bind the hill as it spreads and require no support once it covers the hill..

https://stepables.com

Stepables looks a great site for you....and do look at natural hillsites around you.

Get native wild flowers and ground cover plants. Stepables didn't do well for me in the Texas heat. You need what is native to your area. Even hardy natives will take a bit of extra water to get established.

Natives are always best...just be sure to get the types that have strong spreading root systems to re-enforce the slope integrity

You can plant some low water flowers for landscaping. Add organic mulch, and soil fertilizers to enrich the plant growth. Another option is 'artificial turf'. It doesn't need watering like lawn grass and will help to give an attractive green effect to the steep hill.

Molly..... a little input from you on what look you are after..and how much maintenance you are willing to commit to...will allow posters to offer more ideas that move you closer to your goal...

Artificial turf would not be a good idea. It has no roots to help hold soil. It would eventually be sliding down the hill itself.

Non-natives make it into the world of landscaping because they have some great attributes, often including beauty and durability. Their species is always native to somewhere and often that place has similar characteristics to what is being offered in our yards. I wouldn't discount them in the least. Use whatever works best no matter where it came from. Using non-natives not much different from living in USA and driving Japanese Lexus.

A native groundcover - there are many evergreen choices, most of which flower. And they are well adapted to climate conditions and will require minimal maintenance or watering once established.

I agree terracing is an option as well but only if you have the $$ and inclination to embark on a major landscaping project.

Molly, is the hill, as pictured, covered in something?

I got the impression that the soil was poor quality and hardly diggable. Am I correct?

One thing you do need to watch out for - here in CA - is any plant, like Ivy, that creates a mass under which vermin can establish nests: rats; roof rats; mice; and even rattlesnakes, which while not ‘vermine’ are still undesirable in a family garden.

In the pic it really looks too steep for terracing...everything is possible but this would be a huge project just for the purpose of a nice view out of a few windows...STILL WAITING FOR SOME INPUT FROM MOLLY?

Looks like the hill I had behind my house in Valencia. The developers planted eucalyptus trees, that did grow but were very hard to trim. I tried most everything, flowers, native plants, threw seeds and did get some poppies. What did grow was Rosemary. It filled in, flowered, used it for spices and would add it on the BBQ for smoking. It was low maintenance and low water. I did trim it every few years with a hedge trimmer. And the hill was basically a rock, Decomposed granite.

Right now the OP's hill is covered in a burlap material to stop erosion.

Hi All,
Thank you all so much for the awesome suggestions. I would love to terrace that hill, but I do not think that I can afford to do it. The hill is very rocky and the soil is very hard and sandy, probably clay. Hard to dig in, but I could maybe use an auger and fill the holes with good dirt.

I did consider planting Ivy, however, we do have a rat problem in here. So whatever I do decide to plant on that hill would have to be a space that rats, mice and snakes would not want to hang out in. We also have deer, so the plants would have to be something the deer don’t want to eat. Carmel Creeper? Rock rose? One thought I had was to put a waterfall going down the hill that I could see from my kitchen window. I just want something that looks pretty when I look out my window.

At the left end of the hill I have an area that I would very much like to create a use for as I have very little usable outside space. I would like to put a seating area, maybe a fireplace, some kind of hard scape or a water feature? I think this would be a great place to put a staircase that leads to the top of the hill as there is a nice view up there, however it is currently covered in poison oak.

We are zone 9b.

Here are a few more pics...

Thank you again, I love your input!

You could do grasses, succulents, ground covers

I would say they were so stupid to build a house that close to a hill. but at least it's california and not like some other places.

Any thing you do on a lot like this is going to be expensive... any ground cover will host small critters... and outdoor spaces on a hillside like this are a safety hazard if you don’t build some sort of wall or fence to avoid accidental falls...this may also be the wrong place for outdoor fire elements..it seems to me the best way to create an outdoor living space in your situation may be a deck

Myoporum ground cover https://www.moonvalleynurseries.com/plants/myoporum

It is impossible to keep critters from passing through a planted bed, but so long as you don't cultivate plants that pile up thickly with plant debris, they would not be inclined to make it a home.

I hope it is just camera tricks, but the walk at the back of house appears to be sloping toward the house. If true, that would be worth fixing, as surely, a large amount of water will come off the hill at some point.

At the end of the flumes, it appear that gravel is piled above the flume outfall height. This is going to create somewhat of a dam. It will drain out at the end of a storm but will hold some height of water during a storm when there is heavy flow. I would plan to be out there with an umbrella observing exactly what's happening in order to know if something needs attention.

Do you need to be careful of wildfires? If so, see if the local municipality has a list of recommended groundcovers.

Do you need shade at that side of the house? Some tree forms along the hillside would help hold the soil in place while not blocking the view. The steps to the top (nice wide ones) sound like a great addition if there can be a special viewing spot created there. What flanks your property on the other side of the hill? As one example, a tall bamboo forest (such as Oldhamii) with groundcover below, would look great.

It looks like you have enough room at the end of the house for a more or less linear patio. One with some boulders could look nice.

Keep in mind if you do use bamboo...be sure to use a non spreading variety... bamboo is a huge problem if it spreads..and it does need watering....

Consider Baccharis pilularis 'Pigeon Point', a preferred coyote bush for slope stabilization. It is a tough, drought tolerant, lower growing groundcover that is not preferred by deer. They can also be found offered by some nurseries in flats, which would be a plus since your rocky hill would apparently make it difficult to insert stock with larger root balls.