Iam close to 7 years of exprience in .Net technology,

Question

Iam a full stack developer in .net technology, and its been 6 years 9 months, working in the same company since beginning. By the time i joined product was decently established with all the basic architecture and all the important and basic stuff has been done. Now iaminvloving in only laying down on new features on old code. Its a MVC application(

(c#) with front end frameworks extjs and angular,backend sql server,entity framework.

My long term is to be an architect or solve most complex problems or deal with performance(dont want to enter into any managerial roles).

When i look at my exprience i feel like iam stuck, feeling like ' jack of all and king of nothing' , want to start something(books or videos) and finish off , but directionless, start with what?

Workwise iam contributing just like any other 8 year or 9 year old one in my team.