Late game in solo queue for a Caitlyn is a tough terrain to survive in... And hence the tanky damage dealer build on Caitlyn... At all levels you do a mix of consistent damage plus have a good level of survivability...

The Doran's Blades can be discarded accordingly later on as your HP value increases and fuels your Atma's Impaler (with items like Frozen Mallet, the Health per Level Runes and Banshee's Veil)

Since I usually Mid in solo queue, I prefer taking flash and teleport....

Flash helps me escape dangerous mid ganks and make quick exits when backdooring...

Teleport helps me get back to mid quickly or turn the tides by assisting a side lane or backdooring and drawing attention away from a strong harass push to our inner turrets...

Pros

Not as squishy as the regular Caitlyn, sticky auto attack with frozen mallet, devastates tanks with Madred's Bloodrazor and Last Whisper... Sustainable Damage in 1v1 fights to a certain extent... Higher Chances to survive and clean up in and after a team fight and push the turret....

Meant mainly for solo queue, when you are not sure your team mates can keep there damage dealers off you...

Cons

The current build when completed will lack any form of lifesteal... So if you cannot burst down any high lifesteal build champion in less than 5-6 seconds avoid engaging them in close combat any longer... Make your escape....

If your team does not have a jungler, periodically clear the wraiths and wolves when you have time... Cait excels in farming quickly.... Use it to your advantage...

If possible, constantly harass enemy champion with your "Q" skill in such a way that you get damage off on the minions as well...

It's a personal preference, I use my ult to force an enemies recall rather than to kill them early in the game... It gives me better farm advantage, more experience and eventually makes my enemy weaker late game... Additionally it allows me to quickly go and harass another lane....

Again if you do not have a jungler, when you're lanes are sufficiently pushed or when enemy is dead or otherwise engaged get the jungle buffs... Or help your allies get the jungle buff's so that can be in a better position in game... Taking the red is fine, but if your team has a good Mana heavy user, make sure you share the blue buff...

Last word... I'm not that good a player, however this build helps me survive solo queue pretty well.. It's your call whether you want to use it or not...

Good Luck on the fields of Justice...