Ephemeral environments refer to the ability to create short-lived copies of your system, allowing developers to work in isolated environments, test data not pollute shared environments, and safely tear down environments once a feature is complete. Neon Serverless Postgres solves problems associated with using ephemeral environments with services that charge on a pay-per-use basis, such as increased uptime costs. It provides features like connection pooling, data API, and data branching, which enable instant branching of the database, automatic seed data import, schema-only branching, and automation of creating and deleting branches. Neon is built around PostgreSQL, separates storage from compute, and allows developers to create ephemeral environments for testing and development purposes, while also using it in CI/CD pipelines to ensure clean and well-defined initial system states.