Discuss the implications of soil$-$structure interaction on the design and performance of deep foundations in civil engineering projects. Consider the various factors influencing this interaction, including soil properties, foundation types, loading conditions, and construction techniques. Analyze how different soil types, such as cohesive soils versus granular soils, affect the behavior of deep foundations like piles or drilled shafts. Furthermore, explore the role of geotechnical investigation methods in predicting soil behavior and optimizing foundation design. Delve into the significance of accounting for dynamic loads, such as seismic or wind forces, in the design process, and discuss strategies for mitigating potential issues arising from soil$-$structure interaction. Finally, evaluate the sustainability aspects associated with deep foundation design, considering both economic and environmental factors in the selection of appropriate foundation systems and construction methods.