why is it down for FY2015 net income? And Aren't those margins kinda thin?

They've been reinvesting potential profit into the company in order to grow R&D. (Spend has increased from $57M in FY13 to $141M in FY15.)

Their gross margins are probably what you want to look at instead, since their cost of revenue won't include R&D ($ in 1,000s):

                 FY13     FY14     FY15
  Gross revenue  148,512  215,109  319,521
  Gross profit   115,481  117,123  266,589
  Gross margin   77.7%    54.4%    83.4%

These are very healthy for a software company. They nearly doubled their spend on sales and marketing between FY13 and FY14, which explains the temporary dip in gross margin in FY14.

Not at all. They are investing their profits into scaling and growing the business.

This. And no, software margins are not categorically thin (see SAP, Oracle, Microsoft, etc).

I don't believe those margins are thin by public company standards. Perhaps we are spoiled by Apple who operates at insane margins?

Huge increases in R&D and marketing expenses, mostly.

Doesn't the R&D ramp look a bit unusual? 57 -> 79 -> 141? Totally destroys their margins, right in the year when they must know they're going public?

As a percent of revenue the R&D increase doesn't look as crazy.

R&D as % of Revenue by year:

2013 39%

2014 37%

2015 44%

The marketing and sales expense goes from 13% to 21% of revenue in 2015

The growth in these line items really compress their margins in 2015.

A few year back, I read about their sells process are 100% user self direct into their websites.

I wonder if they stay with that model or do more of the "enterprise sells" now.