Clicktripz Pacing Algorithm Test

When advertisers decide to buy impressions from an ad-network, they buy them in advance in bulk. For example, Tripadvisor might buy 2,000,000 impressions of their new "book direct" campaign at 0.01c per impression.

Pacing is about how fast the purchased impressions are delivered on the network. There are usually two kinds of industry "paces". The first one is "fast" pacing, which means the impressions are delivered as soon as they are available. The second, more commonly used pacing, is "even" pacing. In "even" pacing mode, the impressions are evenly distributed across some time period. That means if a campaign is supposed to show 24 impressions in a day, you would expect to see 1 impression per hour, instead of 24 impressions in the first minute.

Implementing such a strategy involves an algorithm to decide how much to govern or slow-down the impressions being delivered for the advertiser.

Here is an example of how Rubicon (an ad network) does pacing.

Some key points to know about ad networks (and this test) are:

• How many impressions you can show at any time is purely based on the type of websites you have in your network.

• The number of impressions you can show per second changes all the time, and is impossible to predict.

• You won't be able to decide how much you want to slow down your impression count on a real-time, impression to impression basis. You need to allow some number N impressions to be shown before you can update your algorithm. This number N is a constant that you can't control (refresh rate).

Test

Your job is to implement the Pacer class in pacer.py. The Pacer class is used by ImpressionGenerator in campaign.py to limit the number of impressions shown per cycle.

All tests should pass (regardless of how many times they are run) for this project to be considered complete.

Rules

• You cannot change the function signature of calculate_throttle_rate or __init__, but you can add new function methods as you see fit.

• You cannot change tests.py

• You cannot change campaign.py

Usage

You will need to install Docker

See Makefile and Dockerfile.

# builds docker image tailored for this test
$ make build

Turning it in

Once your Pacer class is implemented, send the whole pacer.py file as an email to:

to: jobs@clicktripz.com

subject: <Your Name> Python Pacing Test

body: any comments + gist of Pacer implementation