ChallengeFive.txt

During my past programming experience, I especially enjoyed writting business logic code because of the following reasons:
1. it needs involve business knowledge and contexts to create the data table, schemas, business models and context data structures.
2. it needs business rules invloved for data validation, therefore some validation rule and enginee need created.
3. it needs robust service layer to be created to handle the multithread data trnsactions and retrievals.
4. it needs well designed algorithm to support the convoluted business logic.
5. it needs numerous unit test methods to validate the code logic.

I also enjoyed involving the inhouse API library creation and testing, such as for some special data structure and functionalities: concurrent list, smart sorting, aggregation pipe line, split pipe line, etc. 

Since all the codes are companies' property, I was not allowed to bring the code out after I left the companies, so I really have no code to share. 
You are more than welcome to have me do more coding test or pseudo code writting for some interesting algorithm problem solvings.