Everyone&#x27;s style is going to be differ on the high-level stuff - and you are surely well beyond the point where any random blog post blabbing about software architecture can guide you.<p>Keep walking back to the user and business requirements when you&#x27;re in doubt. In senior technical positions, you aren&#x27;t focused on immediate issues in the code, so much as on developing the right processes to attack those problems. Software isn&#x27;t expected to last very long, and when it does it&#x27;s both miraculous and ugly, as the tools and techniques become more and more arcane over time. If the solution you develop can satisfy all parties for an extended period, it is as correct as you can hope for - and part of that involves choosing a technical process that can be kept running in an environment of some ineptitude.<p>When you know the requirements, model the data first. Data comes first because data lasts longer than code. Flexible data lets you do more with less code. And if the data is very well defined you can usually use fewer language features, too - which is a bonus to maintenance later. Think of features in data terms first and lifecycles later.<p>The best-practices cruft you&#x27;ve learned over time - that&#x27;s going to have to be sacrificed when you identify ways that your designs can be simpler. You may identify a pattern that is useful but not &quot;with the grain&quot; of the languages you&#x27;re using. That doesn&#x27;t mean it&#x27;s wrong, just that you&#x27;re breaking past some known boundaries of programming.<p>As you know, most projects get dirty in order to ship. Not doing that means doing basic research to find the ideal technique, whereas there&#x27;s always room to tolerate a few more hacks, global flags, mystery-meat callbacks, etc. Your best defense is for the data to be so good that all the code can remain disposable and the system will still turn out more-or-less the same way if rewritten from scratch, with a different-but-equally-awful set of hacks and kludges.<p>Under the pressure of strong data, code that sticks around after several cycles of disposal becomes the library code by default - and internal APIs will become strong enough to prevent a &quot;lava layer&quot; from taking root, because they&#x27;ll consistently solve the immediate problem faster than any wrapper layer. The maintainers will feel like geniuses because they&#x27;ll keep finding clever ways to use the existing data better, instead of mashing out another travesty of reflection and classes-on-top-of-classes.<p>If data isn&#x27;t sufficient, you may also have to define a protocol. Protocols, if they work correctly, compact the state management into a small part of the app, and leave you with more data.