Category	Topic	Explanation
Domain concepts		i.e. domain models, business data model
User Experience concepts (UX)
	User interface
	Ergonomics
	Internationalization (i18n)	How to make the system usable in international settings, translation, screen-layout, wording and other
Safety and security concepts
	Security	i.e. how to achieve confidentiality, non-reputiability and other goals.
	Safety	Safety-critical systems are those whose failure or malfunction may result in death or injury or severe financial loss
Architecture and design patterns		recurring patterns within the system
“Under-the-hood” concepts
	Persistency	how / where to store and retrieve data
	Process control
	Transaction handling	How to handle technical or business transactions, i.e. to achieve ACID properties
	Session handling	How to handle user/client sessions
	Communication and integration	How to integrate with other systems, how to communicate (i.e. sync, async, pub-sub…)
	Exception and error handling	What errors to handle, how to handle exceptional situations
	Parallization and threading	How to parallelize tasks, how to create/spawn/manage processes
	Plausibility checks and validation	i.e. client-side validation, how to verify/check data, input, results.
	Business rules	i.e. how to use a rule-engine, how to implement/configure business rules, how to change those…
	Batch processing	How to process data in batches (i.e. offline processing)
	Reporting	How to create reports, how to gather the required data, how to render the results
Development concepts
	Build, test, deploy
	Code generation
	Migration
	Configurability
Operational concepts
	Administration
	Management
	Disaster-Recovery
	Scaling
	Clustering
	Monitoring, Logging
	High Availability
	Load balancing