Potential lenders do not necessarily “track your spending” as they evaluate your credit worthiness.  The three things that are most important to any creditor are the timeliness of your payments, the length of your credit history and the way you use the credit that is available to you.
If you don’t carry a balance on your credit cards for an extended period of time your accounts are still reported to the credit bureaus as being “in good standing” every month.  Plus no balance means no bill, so there is no need to worry about making your payments on time.  Lastly, zero balances on your credit card accounts are a good thing for your debt to credit line ratio, which is the sum of the total amount of debt that you have measured against the sum of your available credit across all of your credit card accounts.  The debt to credit line ratio is one of the factors that potential lenders look at plus one of the factors that determines your credit score.