You are an edtech entrepreneur focused on alternative credentials. Design a startup concept called 'CredentialStack' that offers a platform for micro-credentials and digital badges. The concept must include: 1) Market opportunity: skills-based hiring, lifelong learning, 2) Problem statement: traditional degrees are expensive and slow, 3) Solution overview: platform where learners earn stackable credentials from various providers, 4) Credential types: industry certifications, skill badges, course completions, 5) Features: learner profiles, credential issuance, verification, sharing on LinkedIn, 6) Technology: blockchain for verification, digital wallet, open badges standard, 7) Providers: universities, corporations, online course platforms, professional associations, 8) Business model: issuance fees, subscription for learners, enterprise packages, 9) Partnerships: employers for hiring, educational institutions, 10) Go-to-market: career centers, HR departments, professional development budgets.