Hiring a Mercurial developer provides you with an expert who can manage and track changes in your software development projects efficiently. They understand the distributed version control system, which enables smooth collaboration in your team, especially in a remote working setup. They can handle multiple branches, resolve conflicts, and maintain the integrity of your codebase. Their proficiency in Mercurial also ensures that your projects have a well-documented history, facilitating easy debugging and code reviews, thus enhancing the overall quality of your software.