How do I add together multiple columns based on header names? Here's what my dataframe looks like

Server  Performance123      Performance456                            
server1       1024             0
server2       110              0
server3       0                1024


Here's what I want it to ultimately look like

Server        Tier1
server1       1024
server2       110
server3       1024


Now obviously I could just add the two columns together but I can't be sure what the "123" or "456" part of the CSV I'm importing will look like as it's the last part of the UID of the datastore.

I've tried this

df['Tier 1'] = df.filter(like='Performance')


But I can't assign that as a new column in the dataframe. Any advice? I'm a bit of a newcomer to this so ran out of ideas quickly.
Well after much searching and a lot of errors I have the below working code

df['Tier 1'] = df.groupby(df.columns.str.contains('Performance'),axis=1).sum()[1]