This study investigates the optimization of key process parameters in fused filament fabrication (FFF) to enhance the mechanical performance and material efficiency of additively manufactured Acrylonitrile Butadiene Styrene structures. Three lattice geometries, co-axial joint structure (CAJS), curved wall structure, and mixed star structure, were fabricated whereas varying layer height (LH) (0.1–0.3 mm), infill density (60 %–100 %), and infill pattern (line, grid, and hexagonal). A full factorial design of experiments was employed to analyze the influence of these parameters on compressive strength, surface roughness, and the strength-to-apparent density ratio. Results indicate that infill density is the dominant factor affecting compressive strength, which increased from 42.23 to 83.72 MPa as infill increased from 60 % to 100 %. Surface roughness was primarily governed by LH, rising from 6.86 µm at 0.1 mm to 30.47 µm at 0.3 mm attributed to the staircase effect. The highest strength-to-apparent density efficiency occurred at intermediate infill densities (60 %–80 %), indicating improved load-bearing efficiency with reduced material consumption. Multi-objective optimization using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method identified the optimal configuration as CAJS with a 0.1 mm LH, 80 % infill density, and a grid pattern (TOPSIS score = 0.812). Finite element analysis predicted compressive strength with less than a 4 % deviation from experimental results. The study provides an integrated process–structure–property framework for optimizing lightweight and mechanically efficient FFF-printed polymer components.