Sloped Backyard Retaining Wall with Drainage System

We need an experienced contractor to build a retaining wall along the back slope of our property to stop soil erosion and create a level lawn area. The site is a sloped backyard, roughly 40 feet long, with a grade drop of about 4 feet. We are looking for interlocking concrete block or natural stone construction (open to recommendations) engineered to hold back the soil safely.

Scope should include: excavating a trench for the base, compacting a crushed stone leveling pad, laying the first course dead level and back-sloping each subsequent course into the hill (setback per manufacturer spec), installing a perforated drain pipe wrapped in filter fabric at the base of the wall, backfilling with free-draining gravel behind the entire wall face, and placing weep holes every few feet along the lower courses so trapped water can escape instead of building hydrostatic pressure behind the wall. Because part of the wall will exceed 3 feet in exposed height, we expect geogrid reinforcement layers tied into the compacted backfill at the spacing your engineer or manufacturer calls for, plus proper batter and setback calculations.

Please also address surface drainage above the wall (a swale or French drain channeling runoff away from the top of the slope) and finish grading so water sheds away from the foundation of the house. We would like topsoil and sod restored on the leveled area once backfill settles.

Looking for a written scope, a rough course-by-course plan, drainage layout, and a realistic timeline — we understand this kind of wall typically takes one to two weeks depending on length and height. Please share examples of similar retaining walls you have completed, especially any that needed drainage and geogrid, along with your estimate and start-availability.