Ephemeral environments, also known as Preview or On-demand Environments, are temporary setups that mimic traditional development settings for testing, demos, and reviews without long-term resource commitments. They enhance developer productivity by providing isolated spaces for experimentation and testing, reducing risks of destabilizing the main system and facilitating rapid innovation. These environments ensure consistent deployments by eliminating configuration drift through the concept of Immutable Infrastructure, thus enhancing software reliability and security. However, challenges include provisioning time, data seeding, and subdomain management, which can be daunting for smaller teams. Additionally, potential pitfalls such as cost overruns and infrastructure sharing complexities must be managed to avoid diminishing their value. Despite these challenges, ephemeral environments can significantly boost the efficiency and quality of software development with the right strategies and tools.