Thought I'd post this here since I imagine there's a strong cross-over of interest:
If you'd like a guided video code-tour of how all the pieces of a production web-app fit together, I publish detailed weekly screencasts showcasing the code, systems, and architecture behind Oxbridge Notes, the business that's supported me for the past decade.
So far I've covered:
— software dependency vetting
— data integrity systems (constraints, foreign keys, transactions etc.)
— integration testing systems
— trade-offs in software quality between customer-facing and admin areas
— softer stuff, like designing for SEO (marketing ease is a critical part of any system I design, as an indie-hacker)