“When it comes to building a SaaS, you should be solving a problem in a growing market. A good example I can give is building a SaaS tool for newspaper owners — newspapers are in decline. Or you can build a tool for vibe coding, which only in the last months has been exploding.”

Build in a growing market, not a declining one — same effort, opposite trajectory

Diego frames niche selection as picking the tailwind, not just the pain. Vibe-coding tools vs. newspaper-publisher tools is the same engineering effort but opposite revenue curves. Pick a market that's already pulling builders in and ride the demand wave.