Code reading is the single most expensive development activity. Developers read to understand enough to figure out what to do next. That is decision making.
Much of reading is actually about finding interesting places. Finding the root cause, finding where to add a new feature. Those are search activities. Or visualization ones.
Build custom tools to show the interior of software to support your technical decision making.
Steering Agile Architecture by Example: the Feature Toggles From Open edX
Evaluating @Deprecated classes in Java systems with Glamorous Toolkit
Expressing architectural constraints for a Java system using Glamorous Toolkit