MongoDB provides all aspects of data storage for online retail stores. It can categorize data based on merchandising, content, inventory, customer, channel, sales and fulfilment, insight and social. Out of these merchanding, inventory, customer and insight are the most heavily used for peak holiday sales season.  In addition,  supply chain management system and data warehouse can also integrate well with this database.
We now lookup some of these functions in a table. For example, a catalog is important for the online retail store to allow users to browse the inventory.  The problem with catalog as with any master data management is that data becomes rigid. If the catalog is accessed more than 100 times per second, it causes issue with performance. When other departments need to access it, ETL, message bus and API services are put in place for this store.  This results in fragmented data, redundant processes, heterogeneous data processing and higher costs both in terms of time and money. Even users begin to see degradation in page load times. Another concern with the catalog is that there are many more catalogs formed as it grows. This leads to more caches, more message bus and more ETL operations. A single view of the product and one central service becomes harder to achieve.  The purpose of the catalog is to form a single view of the product with one central service, flexible schema, high read volume, write spike tolerant during catalog update, and to have advanced indexing and querying and geographical distribution  for HA and low latency.
#codingexercise
Find the smallest number k such that the product of digits of k is equal to n
For example, if the input is 100, then the output is 455
                      if the input is 26, then the output is -1

We know that the smallest number possible must have increasing order sorted digits with the smallest digit appearing in the most significant position. Therefore, starting from 9 to 1, we can divide the number repeatedly and keep track of the digit as well as its repetitions for those that are divisors. We stop when we have exhausted the digits we started with or the number is reduced to 1 or 0. We store it in a stack because the sequence of digits and their repetitions need to be reversed to form the answer.  The termination conditions are when n is 1
int GetDivisors(int n)
{
if (n >= 0 && n <= 9) return n;
var divisors = new Stack<int>();
for ( int i = 9; i >=2 && n >1; i--)
{
    while(n % i == 0)
    {
         divisors.push(i);
         n = n  / i;
    }
}
if (n != 1) return -1;
return GetNumberFormedFromDivisors(divisors);
}
This method works well for a single input but if we have a contiguous sequence of inputs, we can utilize the results of the previous computations by memoizing the results and putting them in a dp table. The catch however will be to get all factors and see which combination is smallest.
For example
100 is 20 x 5
20 is already computed as 4 x 5