A GCP (Google Cloud Platform) developer designs, builds, and manages applications on Google's robust and scalable infrastructure. They utilize GCP services such as Google Compute Engine, Google App Engine, Google Kubernetes Engine, and BigQuery to create cloud-based solutions. This includes developing and deploying applications, integrating with databases, setting up data pipelines, and implementing security and compliance policies. They also monitor application performance and troubleshoot issues. GCP developers collaborate with other IT professionals to optimize the cloud architecture and ensure the software meets business requirements. They need a strong understanding of cloud computing concepts and proficiency in programming languages.