Replace config/newrelic.yml
Disable asset pipeline on precompile

Could not push to heroku due to db access in precompile.
Disabling per advice here
https://devcenter.heroku.com/articles/rails-asset-pipeline#troubleshooting
Loop: prefetch icons in one query

This should avoid a lot of unecesarry queries.
Big List: limit data/queries to info needed

 The database is faster at counting than us: it already has the data
 To say nothing of the waste of bandwidth.
Tweets: Use css selector rather than xpath

Maybe they used to, but the elements in question currently have
two classes ( js-tweet-text and tweet-text), so the @class= is
not going to work.

We could do //p[contains(concat(' ',normalize-space(@class),' '),' js-tweet-text ')]
but a) eww. and b) I seriously doubt it would be faster.
Tweets: use legit twitter timeline widget

It is possible I am missing the point of this Kata, but other than
some questions of where exactly to insert the js... I am unclear
on why not to just do it this way. If we really wanted to,
we could hack-up the CSS to display more plain-texty.

Obviously things would be different if we had a reason to
want the tweet text on the backend, but then we should probably use
the JSON API and still not resort to scraping.
Caching: don't use file store, use memcache

Tweak the environment file to use the dalli store, enabling memcache
per https://devcenter.heroku.com/articles/memcachier#rails-3-and-4

I am also suspicious of these keys, but it will be easier to examine
them if we aren't using a file store on a server I can't access directly
Caching: use consistent keys

As I suspected (admittedly I didn't know), rails does not insist
on being so magic as to rewrite cache keys in flight for nefarious
convention over configuration reasons.
Async: move "mail" to a Sucker Punch async job

For something that didn't target free-to-run-on-heroku, I would
presumably using something else with actual out-of-process
workers, probably Resque or Sidekiq.
Many assets: use data URIs on the fly

If we wanted to get even fancier we could have an initializer that
prefetched/prerendered all the icons into one giant image and
use CSS sprite maping

In the middle is the option of caching the pre-encoded data-uris
in memory, memcache, or even right in the DB.