Note: Salesforce has a standard VLOOKUP function but has limited functionality, this approach helps overcome those without code.

Process Builder and Flows are recent automation engines provided by Salesforce, they have been around for a while but haven't been used widely i believe (probably developers tend to stick with Apex Triggers and Workflow rules as they are used to it)

The use case below shows you how you could use these two together to solve a simple scenario which as a developer we tend to solve with Apex Code.

Scenario:

Everytime a Product2 record is updated, i have to query if this product exists in a custom object (Exempted parts) and based on the result update a boolean field on Product2.

Solution:

STEP 1:

Create a Flow (Product2_Validate_Exemption)

STEP 2:

Create a Process and call the flow every time a product2 record is updated.

Reference: This example uses the great search component provided by Avinava Maiti. His blog is here 
http://blogforce9.blogspot.com/

Problem:

Using a standard lookup field on the user object, Salesforce does not allow you to lookup a user who is of the license type 'Chatter Free'.

Solution:

Although you cannot use a standard UI to update the user lookup field with a chatter free user, you can update the field through the API. This means that we could use a visualforce page to populate the lookup field.

Assumptions:
We will use a custom type ahead advanced search component.
We will use a custom field 'Chatter Free user lookup' on the account object.

STEP 1:
Install the autocomplete search component from here

http://blogforce9dev-developer-edition.ap1.force.com/ProjectDetail?id=a0290000009KusM


STEP 2:

Create the following apex class


STEP 3: Create the following visualforce page:democustomlookup

STEP 4: Create a new custom button on the account object.
STEP 5:

Add this custom button to the page layout and you are done.

RESULT:

Lightning Experience / Lightning UI:

• Lightning Experience can be turned ON at the profile level, or for individual users using permission sets.
• ALL standard profiles are lightning UI enabled by default, when you enable Lightning UI for your organization. [Workaround: Replace standard profiles with custom profiles]
• Visualforce pages work as usual in the lightning UI, however you might want to do a sanity check to make sure nothing is broken.
• Visualforce pages open with the old look and feel. The old look and feel is referred to as Salesforce Classic.

Where to learn more?

There are tons of resources in trailhead. Collect your badges and learn the fun way.

https://developer.salesforce.com/trailhead/trail/lex_admin_migration

Lightning Design System:

Lightning Design system is a front end framework for developing web applications. Using the Lightning Design system you could design visualforce pages or standalone web pages that look and feel the same way as the Lightning UI. A few pointers.

• Lightning Design system could be though of as an equivalent to 'Twitter Bootstrap'.
• To download and start using visit https://www.lightningdesignsystem.com/
• The design system is purely made up of CSS files.
• The design system comes with pre-built components such as pop-up modals, tree structure, buttons etc.
• Lightning Design system focuses mainly on the front end. Data manipulation and processing will still be done using Apex and Visualforce/other desired markup language.

Where to learn more?

 Trailhead again. Use this trail to learn more https://developer.salesforce.com/trailhead/module/lightning_design_system

Lightning App Builder:

The Lightning App builder is a drag and drop tool to build lightning pages. Salesforce offers a few components by default, including 'Recent Items', 'Assistant', 'List View' etc. In addition you can create your own custom components using the Lightning Design system, or use third party components supplied by AppExchange applications like SKuid

Access from SetUp -> Lightning App Builder