... let me know if its good coding.

What follows is in part my own personal preference, but a lot is current idiomatic Perl; I won't rigorously distingush between the two. My comments pertain to your

local( $/, *FH ) ;
open( FH, '<', 'aws.json' );
my $text = <FH>;
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section of code; the rest is from the AnonyMonk's post and looks good to me. Caveat: I haven't actually tested any of the code on which I'm commenting.

•     local( ..., *FH ) ;
      open( FH, '<', 'aws.json' );
  local-izing package global variables is better than nothing and you're already using the three-argument open, but it's even better to use a lexical filehandle and check the success of the file open:
      my $filename = 'aws.json';
      open my $fh, '<', $filename or die "opening '$filename': $!";
  (You could also turn on autodie globally with a  use autodie; statement, but I prefer the flexibility of individual die clauses.)
•     local( $/, ... ) ;
      ...
      my $text = <FH>;
  To do this idiomatic file "slurp" read,  $/ must be undefined. Again, globally undefining this variable (and that's effectively what you're doing, even using local) is not preferred: local-ize in the narrowest practicable scope:
      my $text = do { local $/;  <$fh>; };
  
• With the previous two changes, the
      local( $/, *FH ) ;
  statement (and its possibly problematic global effects) goes away entirely. (Update: Actually, the  local( ..., *FH ) ; statement effectively has no semantic global effect WRT the  *main::FH glob because it is local-izing the glob at the top level of the script, where all globs come into existence anyway. The only practical "global" effect is on your expectations: you may be lulled into thinking that you have invoked some kind of magical protection for yourself when you have not.)