Practical construction.
WHAT TO PLAN BEFORE BUILDING
The data structure Who uses it, and on what devices What the process actually is
WHY THE DATA STRUCTURE FIRST
It is the most expensive thing to change later.
WHAT TO DESIGN FOR
Phones, if people will use phones.
WHY
An application designed for a large screen is unusable on a phone.
WHAT TO KEEP SIMPLE
The number of screens The number of controls per screen
WHAT TO NAME CLEARLY
Every screen and control.
WHY
Default names make formulas unreadable.
WHAT TO AVOID
Complex logic duplicated across screens Loading entire data sources into the application Formulas nobody can follow
WHAT DELEGATION MEANS
Operations performed by the data source rather than by the application.
WHY IT MATTERS ENORMOUSLY
Non-delegable operations process only a limited number of records, silently producing wrong results on larger data.
WHAT TO CHECK
Delegation warnings, and address them.
WHAT TO TEST
With realistic data volumes, on a real device, offline.
WHAT TO DOCUMENT
What the application does and how it is structured.