Start by looking for experience that matches the type of system, technology and delivery model required by your project.
A reliable provider should ask detailed questions about your business goals, users, current software and technical dependencies before recommending a solution. The team should also explain how it approaches architecture, testing, security and project communication.
The cooperation model should reflect your internal capabilities. You can outsource the complete project to an external provider or add selected specialists to your existing team.
Whichever model you choose, responsibilities, reporting rules and decision-making processes should be clear from the beginning. Regular updates and access to project information help you maintain control over the scope, budget and progress.