As a Drupal developer contractor, your main responsibility would be to develop and maintain Drupal-based websites, applications, and systems. Your tasks may include:

1. Developing and customising Drupal themes and modules based on project requirements.
2. Writing custom PHP code and integrating with third-party APIs.
3. Designing and implementing content types, views, and workflows.
4. Creating and executing test plans to ensure code quality and functionality.
5. Troubleshooting and resolving issues with Drupal-based websites and applications.
6. Providing technical guidance to other team members and stakeholders.
7. Staying up-to-date with the latest Drupal trends, technologies, and best practices.
8. Collaborating with project managers, designers, and other developers to deliver high-quality projects on time and within budget.

To be successful in this role, you should have a strong understanding of Drupal architecture, theming, and module development. You should also have experience with PHP, HTML, CSS, JavaScript, and MySQL. 

Excellent problem-solving and communication skills are also essential to work effectively with other team members.