TK Kader lays out five concrete SaaS business ideas designed specifically for solo founders --- people who want to build and ship a product without raising venture capital, hiring a team, or finding a technical co-founder. Rather than offering generic advice about "solving a problem," Kader names specific niches, target customers, and monetization models for each idea. He focuses on markets where the competition is fragmented and the incumbent solutions are outdated, expensive, or overly complex --- creating openings for a focused, well-built alternative. Kader discusses the AI-enabled SaaS landscape, where solo founders can leverage LLMs, APIs, and no-code tools to ship products faster than ever before. He also addresses the unit economics, go-to-market approach, and realistic revenue expectations for each idea, making this less a brainstorming session and more a feasibility analysis for anyone considering the solo SaaS path.