A Greenfield project refers to a software development project that starts from scratch without any constraints or dependencies on existing systems or code. The term is borrowed from the construction industry, where "greenfield" denotes undeveloped land, free from previous work or structures, allowing developers to work with a blank slate.

In software development, greenfield projects offer the freedom to use modern technologies, tools, and methodologies without the limitations or technical debt associated with legacy systems. This can lead to faster innovation and adoption of cutting-edge solutions like microservices, serverless architectures, or cloud-native infrastructures. However, while greenfield projects provide more flexibility, they also come with challenges, such as increased design complexity, lack of an existing user base, and the need for extensive planning to ensure scalability and maintainability.

The opposite of a greenfield project is a brownfield project, where development occurs on existing systems, requiring integration with legacy code or technologies.