Introduced for some time now particularly in Winter 15. Queueable Apex addresses some short coming of the @future methods. It’s an offspring of the marriage of @future methods and Batch Apex.

Queueable Apex allows you to submit jobs for asynchronous processing similar to future methods with the following additional benefits:

• Non-primitive types – you can pass SObjects and custom apex types
• Monitoring – you can monitor the job from the Apex jobs page in Setup or query the AsyncApexJob record
• Chaining Jobs – create sequential jobs

 

How to use Queueable Apex:

• Create a class that implements the Queueable interface

• If you are going to make callouts you need to extend your implementation to Datatabase.AllowCallouts

• To allow multiple primitive types, create a constructor and call the public void execute method.

• To execute the class, call it from your logic

• There you can chain jobs by calling another Queueable class on the execute method.

Things to note: This counts to your limit of 250 limits for asynchronous process per 24 hours.