Looking for Reliable Software Development Services for a Custom Project

I am in the process of looking for software development services that can build a custom business solution. The solution requires the development of a web-based framework that needs a particular combination of abilities and capacity to scale. I am seeking a development team that brings proficiency in full-scale operations starting from design work up to deployment needs with post-launch support. I need advice about software development services from either companies or freelancers so I would appreciate feedback on specific professionals who have handled projects. In choosing a provider what selection criteria will yield the most benefit and what signals should indicate to me that a provider should be avoided? I appreciate in advance your valuable feedback regarding this matter.