I recently finished Software Architecture: The Hard Parts (Neal Ford, Mark Richards, and others), and it was a turning point in how I think about software engineering. The main lesson I carry into my own projects is that, in modern architecture, "it depends" isn't a cop-out — it's the most technical and mature answer a developer can give.
The book dismantles the search for one definitive solution and puts the focus where engineering actually happens: trade-offs. When designing systems and structuring a backend, it becomes clear there's no such thing as a universal "best practice" — only choices and their consequences within a specific context.
The myth of total decoupling
Splitting systems into microservices or smaller modules doesn't eliminate complexity — it just relocates it. Coupling will always exist; the real technical challenge is choosing which kind of coupling your system can tolerate (static vs. dynamic, for instance). Chasing "zero coupling" is chasing a ghost.
Data is the actually hard part
Splitting code into smaller pieces is relatively easy with today's frameworks. The real architectural barrier is managing transactions and data consistency across distributed systems without wrecking performance. That's exactly where most monolith-decomposition projects get stuck.
Documenting the "why"
One thing I especially valued was the case for keeping Architecture Decision Records (ADRs). What makes a design good today might not make sense tomorrow, and the documented context behind a decision saves hours of discussion and rework later — especially once the person who made the call is no longer on the team.
This reading changed my practical approach to building software. My focus shifted from simply "making it work" to critically analyzing service granularity, the communication patterns between them, and how each decision affects the system's scalability and maintainability over the long run.