Planning and prototyping new applications. Designing the architecture of the components of an application. Deciding on the best technologies and languages for the project. Testing sites and applications in different browsers and environments. Problem solving. Fixing bugs in existing projects. Testing new features thoroughly to ensure they perform the correct task in all cases. Running performance benchmarking tests. Building and testing Application Program Interfaces (APIs) for applications to exchange data. Researching, incorporating and contributing to Open Source projects. Gathering requirements from clients and users. Learning and testing new technologies, frameworks and languages. Staying up to date with new trends and advancements in web development. Building and maintaining databases. Refactoring and optimising existing code. Documenting code so other developers can understand and contribute to it. Designing information architecture within an application or website.