We only hire the trendiest

Being in the IT job market off and on for the last 18 months and being interviewed at about 40 companies in one of the major tech hubs in the USA, gave me a similar experience as the OP. I came to several conclusions:

1) In my case trendiness is more valuable than the school you've graduated from (graduated from a school overseas that nobody in the USA heard of). I worked for one of the companies in the area, notorious for its difficult tech interviews and I got a bunch of calls from recruiters (including from Google) during my tenure there and immediately after I left. Two years and few short gigs at not-that-cool-companies later, I don't get that amount of calls.

2) Most of the "technical" recruiters have no clue how to evaluate technical candidates. For many of them the main (for some the only) way to judge about your skills is how much money you make/how much money you want. I'm talking about deep understanding what engineer do, I'm talking about basic stuff.

3) If you have 1-2 short gigs for the last couple of years you are under the suspicion that you can not be trusted enough to be hired as a FTE.

4) If you are unemployed at the moment of the interview - look 3) I believe now that hiring in the IT industry is somehow a stochastic process. I was hired and got offers from reputable companies and organizations and rejected even at the first round of interviews by no-name/less-than-mediocre-companies. Go figure.

Really? Everyone I know in the .Net world is busily building upon open source libraries via Nuget, which is an NPM equivalent. Most of that open source code is hosted on Github.

Now .Net is now also open source it would seem that the only proprietary part to the stack is Windows itself, and shortly .Net is going to be running on any platform.

It saved us enormous amounts of time at Matasano. When we designed our work-sample rubric, our #1 concern was filtering out people who interviewed well and/or had great resumes but weren't worth a billable hour on a real project, but our #2 concern was interviewing faster and getting results back to candidates quickly. (We didn't discover the best reason to do work-samples --- discovering hidden talent --- until after we'd started doing them).

With standardized interviews and challenges, our whole hiring pipeline became entirely mechanical. We could send our a challenge and its instructions in 2 minutes, and evaluate the response the next day (or week, or whatever) later in less than 5 minutes. 7 minutes, to produce a technical evaluation that crushed a competing battery of tech interviews by several senior staff members that took 4-5 hours to do.

> Would you feel the same way about someone who is currently doing .Net but has experience with other technologies in the past, and still learns and uses non-MS technology outside of their current job?

No, certainly not. But I've reviewed resumes of folks who were clearly just cogs in the Microsoft machine (without any indication that they were doing things with Unix & free software in their free time). I really am concerned about bringing in someone like that.

I like your breadth of experience, particularly your usage of Python. Many of my concerns about .Net are applicable to iOS, and I have other concerns about Java, and still other ones about PHP, but anyone who uses Python is probably a good egg.

So far none of the responses have gone on a business tangent, yet usually business guys are the ones who decided on / enforced the MS-only doctrine. I assure you some MBA veep who's never touched a keyboard did not make the decision based on the accurate technical details in some replies.

The first one is hiring. Supposedly everyone knows windows, great hiring pool. I donno if I believe that anymore, but in the old days there was certainly no shortage of MCSE to hire. It doesn't matter if the UI for the OS and office software change completely every couple years because "everyone knows windows" so training costs only exist for alternative OS or alternative office software. When that linux genius quits he's irreplaceable, isn't he? That's a great position to be in if you're that guy (me), but business people hate that. To some extent this is a young person vs old person problem because college campuses (campii?) are owned by apple, not MS. MS is just to run the dorm xbox, that's all. This is strategic planning on the part of decision makers.

The second is financial embrace and extend. Once you got one windows server or a couple desktops, inevitable licensing agreements make the marginal delta of "another windows box" extremely cheap (maybe zero) vs the measurable costs of mac etc. BSA / etc audits will make your life a living hell unless you participate in this scheme. This is bean counting on the part of the decision makers.

The third is interoperability. Unless you're the worlds most boring company you'll be doing something weird and under the first topic above, everything weird has by default windows clients or drivers or applications. There will be a windows client for an eprom programmer or I2C driver. There might be alternatives but it will work under windows. Then see the topics above. You will need windows boxes... you just will. This is pragmatism on the part of the decision makers.

The fourth is CYA. Like decades ago, "nobody ever got fired for buying IBM" today "nobody ever got fired for buying MS". You could get fired for buying a mac and it doesn't work, or installing linux on a server that crashes, but no quality of service, including zero, is low enough to get fired for buying microsoft. No matter how badly the system gets powned or how much stuff gets stolen, you can't get fired if you bought MS products. Just doesn't happen. If you can afford it, and you like being employed, the decision seems clear from a risk management perspective. Cowardice on the part of the decision makers.

The fifth is support. Business people think we get support by calling a script reader in India who tells use to wipe, reinstall, and reboot, and furthermore that is worth money and worthy of making procurement decisions. In the real world we know we use google for support and non-MS stuff googles better. But business people like a risk management of a nice security blanket of telephone support from a dude with a nice looking certificate. Its not actually useful of course, but business people don't understand it. Business people think computer support is like medical support and you call 911 and get fixed up, but 911 converted to computer support would be a pretty funny standup comic routine. Essentially this is plain old ignorance on part of the decision makers.