Portfolio and Experience
The first thing you should examine is the agency's portfolio. Do they have projects similar to what you need? An agency with broad experience will have worked across different industries and will know how to tailor solutions to your specific requirements. Don't settle for visual appeal alone - check whether the websites they've built function well, load quickly, and provide an intuitive user experience. International experience is a significant advantage, as it demonstrates the agency can work to high standards with diverse clients from around the world.