Max Rossmannek developed a scalable addition feature for sparse observables in the Qiskit/qiskit repository, enabling users to add two observables with a complex scalar multiplier. This enhancement supports more expressive quantum algorithms and streamlines Hamiltonian construction. Max implemented the feature using C and Rust, focusing on algorithm design and quantum computing principles. The work included stability improvements, such as refined memory management and removal of obsolete flags, as well as comprehensive documentation updates to clarify usage and semantics. Through code review and collaboration, Max ensured the solution was robust, well-documented, and integrated seamlessly with existing Qiskit functionality.