get '/' => sub {
  my $c = shift;
  $c->render( template => 'index' );
};

post '/' => sub {
  my $c = shift;
  my ($opt) = $c->param('option');
  app->log->info("Option $opt");
  my $result = do_something($opt);
  $c->render( template => 'result', c => $result );
};