We continue reading "Modern data Fraud Prevention at Big Data Scale". Feedzai enables companies to move from broad segment based scoring of transactions to individual oriented scoring with machine learning based techniques. Feedzai claims to use a new technology on a new platform. They claim to have highest fraud detection rates with lowest false positives. Feedzai uses real-time behavioral profiling as well as historical profiling that has been proven to detect 61% more fraud. They have true real time processing. They say they have true machine learning capabilities. Feedzai relies on Big Data and therefore runs on commodity hardware. The historical data goes as far back as three years. In addition, Feedzai processes realtime data in 25 milli seconds against vast amounts of data at 99th percentile.  This enables fraud to be detected almost as early as when it is committed.

We mentioned their machine learning capabilities. These include:
In-memory event streaming processing which enables fast response
use of NoSQL on commodity servers which enable it to scale
Continuous learning as history builds and the accruing transactions are used to learn
Detection of anomalies no matter how outlier they may be
Reduction in time to process the transactions and 
reducing the cost overall for all transaction processing
The challenge that comes with fraud detection is that fraud often mimics genuine customer behavior so they are harder to tell apart. The classifiers used by Feedzai have very low false positives. The manually learned rules over the years had not yielded such low level of false positives as these algorithms do. Consequently, it the size and computation that distinguish Feedzai from its competitors. 
#codingexercise
describe merge-sort
Merge-Sort(A,p,r)
if (p < r)
  then q <- (p + r) / 2
         Merge-Sort(A, p, q)
         Merge-Sort(A, q+1, r)

         Merge(A, p, q, r)

MERGE(A,p,q,r)
// Initialize L and R arrays with left and right partitions of A at boundary q
// and to have one more element at the end to have a max integer value
i = 1
j = 1
for k = p to r
     if L[i] <= R[j]
         A[k] = L[i]
         i = i + 1
     else
         A[k] = R[j]
         j = j + 1