A Design and Implementation Developer is responsible for creating and executing software solutions to meet business needs. They conceptualize and outline system flow, data usage, and work processes by creating detailed designs. They then translate these designs into software code, integrating it with existing systems while debugging and testing for any errors. They also ensure that the implemented software is robust, scalable and secure. Furthermore, they take part in peer code reviews, maintain documentation, and may provide technical guidance to other team members. Their role is crucial in the entire software development life cycle, from inception to post-implementation review.