Attempt at backend trial

[hbierlee]

I wanted to send in my work before the end of the day, although I'm aware it's far from perfect. I sort of solved the problem by using SQL get booking counts and turnover per month per booker, and then use some PHP array folding and grouping loops to proces it further to what I think is a LTV report.

That said, I might have misinterpreted the assignment. I have interpreted it like this (if we take a LTV period of 18 months and commission of 10%):

• Profit is of course turnover * commission
• A LTV report has LTV values for all the past months longer than 18 months ago.
• A LTV value for a certain month X is basically the average profit made by only those bookers who made their first booking on month X, and only in the period of month X, X+1, ..., X+17 (so, an 18 month period starting from month X). So, for instance, turnover in that period made by a booker who has made their first booking in month X+2 does not count towards this value.

This last part is what made the whole thing a lot tougher, so if I understood this wrongly, I would very much like to hear it so I can solve it properly. Otherwise, I'd love to hear some pointers on how to tackle this problem, as I only got so far with SQL.

[vdvleon]

I think you understood is correctly. Is your code ready to review in this case?

[hbierlee]

In that case, it is ready for review. Like I said, it's definitely not the optimal solution, and some of the requirements have not been met, but I think at this point it'd be better if you take a look at it and gave me some pointers.