Chapter 19 — Choosing the Appropriate Architecture Style

Core ideas — the decision process

1. Determine whether monolithic or distributed is warranted (driven by whether different parts need different architecture characteristics → back to the quantum, Chapter 7).
2. Determine where data should live (shared vs. isolated).
3. Determine the communication style (synchronous vs. asynchronous) between services.

• Inputs to the decision: the prioritized architecture characteristics (Ch. 4–5), the domain/partitioning, data architecture, and organizational factors (team topology, Conway’s Law).
• There is no universally correct style — architecture is context- and time-bound; today’s right answer can be wrong in three years (hence evolutionary architecture + fitness functions).

Trade-offs to argue

This chapter is the trade-off chapter. Practice mapping a prioritized characteristics list to a style using the star-rating comparison table you built across Part II.