90 East End Avenue is a sprawling residence offering approximately 3,100 square feet of impeccably composed living space, where light, proportion, and materiality are handled with rare discipline. This expansive 3-bedroom, 3.5-bath residence has open exposures on all sides framing sweeping views of the East River, Carl Schurz Park, and the skyline beyond - bringing a sense of continuous calm from room to room. Conceived by GRADE with a clear architectural vision, the interiors balance warmth and restraint through wide-plank rift-sawn white oak floors, custom lacquered cabinetry, and hand-crafted finishes, including eucalyptus paneling and bespoke millwork throughout. Venetian plaster ceilings, refined wall treatments, and polished metal accents create a layered yet understated backdrop - elevated, never ornamental. A gracious entry gallery opens to an expansive great room ideal for entertaining, complemented by a separate media room offering rare flexibility for a den, library, additional living space, or potential fourth bedroom. The kitchen is seamlessly integrated, featuring stunning custom Nano glass counters, integrated Sub-Zero refrigeration, Wolf and Miele appliances, and concealed storage that reinforces just how well done this home's clean, architectural flow is showcased. The primary suite is a private retreat with dual walk-in closets and a spa-level bath clad in Blue de Savoie marble, custom stone sinks, and Dornbracht fixtures. Secondary bedrooms are generously scaled, each with an en-suite bath, bespoke storage, and tailored finishes that feel intentional yet effortless. 90 East End Avenue, which was originally designed by renowned architect Costas Kondylis, offers full-service amenities including doorman and concierge, fitness center, and children's playroom - all set on one of the Upper East Side's most beautiful and tranquil riverfront blocks. A home where craftsmanship, alignment, and light are handled with rare clarity.