People ask how a solo developer ships a booking engine in two months. The honest answer is boring: fewer choices and a clear definition of the part that cannot break.
Start with the fatal risk
For a resort it is a double booking, so reservations use PostgreSQL row locks (Custom Booking Engines). For a hiring platform it is a message that never arrives, so WhatsApp is a first-class channel (WhatsApp-First Products). Build that first, prove it, then add features.
A stack I do not have to think about
Next.js for the web, React Native for mobile and kiosks (why), PostgreSQL for data, Docker on Google Cloud for deploys. Every hour not spent evaluating a new framework is an hour on the client's actual problem.
Demo every week
Clients do not read specs, they react to software. A working slice each week catches the wrong assumption in week two instead of week seven.