Speed up Store Procedures in SQL 2016 database

In short: I need an expert to take a look at my database, to optimize its speed. He needs to a look at indexing/columnstore indexing and maybe converting scalar functions to Tabular functions. In particular I have a Store procedure that takes 1:30 (1 min 30 sec) to run. I need it to run in under 10 seconds. It returns Products/Accounts/QTY/Value etc... It may require better indexing of tables, the use of columnstore index converting functions etc... The main table has 225 000 rows, with 6 [login to view URL] main slowing part is the looking up the price of product at certain time period, as well as exchange rate. These are functions that take long to run, because they are Scalar functions. I general the person to apply for this project is required to be an expert in TSQL and sql server. the database is running in SQL 2016. I need this to finish with in 7 days.