Sago starch, rich in polysaccharides (approximately 85%), primarily consists of amylopectin (70–80%) and amylose (15–30%), making it a promising substrate for maltose syrup production as an alternative to cane sugar-based sweeteners. This study aims to optimize both the substrate concentration and the saccharification duration through the simultaneous application of pullulanase and β-amylase, aiming to enhance hydrolysis efficiency and shorten overall processing time. The enzymatic treatment was applied to sago starch concentrations of 10%, 15%, and 20% (w/v), and saccharification was monitored over a time range from 6 to 72 hours. Results revealed that a 20% substrate concentration yielded the highest maltose content and reducing sugar levels, along with a notable increase in dextrose equivalent (DE) and viscosity. For instance, at 48 hours, the maltose content reached 26.79%, reducing sugars 35.85 g/L, DE 25.14%, and viscosity 49.75 mPas. This treatment significantly improved saccharification rate, sugar conversion, and overall product quality by promoting efficient enzymatic synergy and substrate utilization. Optimizing these parameters not only enhances conversion but also offers a more sustainable, cost-effective, and scalable approach for sweetener manufacturing. These findings provide valuable insights for the food and biotechnology industries, particularly in developing reliable, eco-friendly alternatives to conventional sweeteners, and highlight the industrial potential of sago starch in high-value, functional food formulations and health-focused products.