Salesforce Sales Cloud
Apex coding (Classes, triggers, asynchronous)
Understanding of force.com sites 
Lightning Aura development
LWC is good to have
Very good understanding of products, pricebooks etc.
Below are day to day activities:

Apart from Sales Cloud, there are several applications built on Salesforce platform to fulfill sales processes and some product related functionalities. Typical requests are 

To fix issues in these existing applications. Issues could be config related or custom development related.
Develop new functionality in existing applications. New functionality may require just configuration setups or also apex development.
Work on Sales cloud Account, Contact, Opportunity changes and issues.
Sometimes develop new application using lightning.
Be part of daily standup and scrum to discuss daily progress and issues