Guidewire Interview Questions

Enhancements in Gosu allow you to add methods and properties to a class without sub-classing it or having access to its source code. It is resolved at compile time. A Class Extension (eti/etx files in GW) specifically refers to extending the Guidewire Data Model entity. While enhancements add behavior (methods), entity extensions add state (columns/fields) to the database layer.

Gosu handles nulls differently than Java. An expression like `A.b.c` in Gosu is null-safe by default. If `A` or `b` is null, the entire expression evaluates to null rather than throwing a `NullPointerException`. However, if you explicitly call a method on a null object, it will throw an NPE. You can use the `?.` safe property navigation operator in some dialects or depend on standard Gosu null-short-circuiting.

PCF stands for Page Configuration Format. It is an XML-based file that controls the UI rendering in Guidewire. A PCF structure typically consists of a `Page` or `Popup` at the root, containing `Variables`, `Screen`, `Panels` (like DetailViewPanel or ListDetailPanel), and `InputControls` mapped to Entity fields.

An Entity represents a database table (e.g., Claim, Policy) that stores transactional data and has a primary key. A Typelist (`.tti`/`.ttx` file) represents a static list of drop-down values (e.g., `LossType`, `State`). Typelist values are loaded into memory on server start for fast access and handle localized strings internally.

When a transaction is committed to the database, GW evaluates Event Rules. If an event is triggered (e.g., `ClaimAdded`), a message is generated and placed into a Message Queue. A Message Destination then acts upon this queue, picking up the payload and sending it to an external system, enabling asynchronous integration.