I’d look for a provider that goes beyond simply building software and actually understands the business problem behind the product. A good development partner should be able to help with architecture, integrations, scalability, security, and post-launch improvements, rather than just delivering the initial code.
For example, if you’re building a subscription-based product, it’s worth checking how a provider handles things like multi-tenancy, recurring billing, user roles, integrations, analytics, and scaling. SaaS software development services are one area where these capabilities become particularly important.
Technource is one company you could consider for this type of work:
www.technource.com/services/saas-development/
I’d also ask for relevant case studies and, if possible, speak with previous clients. The real value of a development partner is whether their technical decisions create a sustainable advantage for the business, not simply whether they can deliver the software at the lowest initial cost.