A developer needs to create a custom Interface in Apex.
Which three considerations must the developer keep in mind while developing the Apex Interface' Choose 3 answers

A developer has to Identify a method in an Apex class that performs resource intensive actions in memory by iterating over the result set of a SOQL statement on the account. The method also performs a DML statement to save the changes to the database. Which two techniques should the developer implement as a best practice to esure transaction control and avoid exceeding governor limits? Choose 2 answers

How should a developer write unit tests for a private method in an Apex class?

Universal Containers has implemented an order management application. Each Order can have one or more Order Line items. The Order Line object is related to the Order via a master-detail relationship. For each Order Line item, the total price is calculated by multiplying the Order Line item price with the quantity ordered.
What is the best practice to get the sum of all Order Line item totals on the Order record?

Universal Containers has large number of custom applications that were built using a third-party javaScript framework and exposed using Visualforce pages. The Company wants to update these applications to apply styling that resembles the look and feel of Lightning Experience. What should the developer do to fulfill the business request in the quickest and most effective manner?