In response to the limitations inherent in methodologies reliant upon manual operations and practical experiences, commonly employed within the domain of load forecasting, such as convoluted operational procedures and suboptimal accuracy rates, this study introduces a novel online short-term load forecasting software solution. The developed software leverages cross-platform programming languages, notably Java and Python, alongside an object-relational mapping (ORM) framework to encapsulate database interactions, while adopting a browser/server (B/S) architecture. Furthermore, the software’s development process incorporates appropriate design patterns from object-oriented design (OOD), establishes an exception-handling architecture, and adheres to principles of test-driven development (TDD) to uphold superior software quality standards. Upon completion of construction and rigorous testing, the online short-term load forecasting software exhibits exceptional responsiveness to evolving functional requirements, thereby demonstrating its adaptability and scalability. Furthermore, its sustained operation over an extended duration underscores both its engineering feasibility and intrinsic software quality.