Step 1 — Filter by Relevant Experience, Not General Capability
A company whose portfolio spans e-commerce, healthcare and mobile games is a generalist. If you are building a logistics SaaS, you want a partner who has done it before — one who understands the integration landscape, edge cases and compliance specific to your domain. Ask directly: have you built something at this complexity and in this industry? If the answer is no, ask how they plan to compensate. The portfolio review is not about admiring finished work — look for evidence of process: discovery documentation, wireframes, post-launch performance data, and references who can speak to how the vendor behaved when things got difficult.