
Ask HN: Who is using the .NET stack for their startup? - nirajs
Who is using c# or f# for their startup? I am compiling a list of startups using .net stack. I would appreciate your help.
======
orlandpm
At Tachyus ([http://tachyus.com](http://tachyus.com)) we have made a huge bet
on F#, and it has paid off in spades. The back end of our SaaS product is 99%+
F#, and so far we have had a great experience using Azure for hosting. Our iOS
apps are also built using 99%+ F# (using Xamarin, on Mono rather than .Net).
The language allows us to write highly expressive code, and fewer lines of
code overall.

Using a Microsoft language has given us huge productivity benefits (most
notably Visual Studio and Azure support). There is a fantastic F# community
([http://fsharp.org](http://fsharp.org)) which is untethered to Microsoft, and
it's exciting to see the language grow as an open-source and cross-platform
tool.

~~~
jchonphoenix
How does this compare to OCaml or Haskell? Most of the "benefits" you've
mentioned here aren't actually benefits, but par the course for a programming
language no matter what stack you choose.

Visual Studio seems to be the only real benefit I'm seeing (and I agree, it's
a very major benefit).

~~~
logicchains
Compared to OCaml, F# has slightly nicer syntax, real multi-threading, and
type providers (can e.g. automatically generate a type from a database
schema). It lacks OCaml's awesome module system, higher-kinded polymorphism,
OCaml's neat but rarely-used object system (it has C#'s object system hacked
on instead), and on Mono at least it is generally slightly slower than OCaml.

In my view the .net libaries are probably the biggest advantage over OCaml and
Haskell. Similar to how access to Java libraries gives Clojure an advantage
over lisps like Common Lisp and Racket.

Oh, and if you want to use Windows without mingw then F# is a far better
choice than OCaml or Haskell. The OCaml packaged manager doesn't even work
properly on Windows, as far as I'm aware.

~~~
_random_
Also it seems new versions of F# are released much more often than those of
OCAML. Corporate backing is important.

~~~
lpw25
They both seem to produce a new version about once a year, so there's not much
difference there.

------
dazbradbury
We use .Net MVC (C#) at OpenRent [1].

Might be worth checking out bizspark [2], as I know it lists lots of startups
that are using a .net stack.

Also probably worth mentioning what you're compiling the list _for_ if you
want more responses from HN users...

More info: We actually don't host on Azure (Web Sites not flexible enough for
us), but use a mixture of AppHarbor [3] (awesome product and team), and
various Amazon web services.

[1] - [https://www.openrent.co.uk](https://www.openrent.co.uk)

[2][http://www.microsoft.com/bizspark/partners/startups.aspx](http://www.microsoft.com/bizspark/partners/startups.aspx)

[3] - [https://appharbor.com](https://appharbor.com)

~~~
vyrotek
_" Web Sites not flexible enough for us"_

Would you care to share any specifics? I'm curious to know what you're trying
to do that doesn't work on Azure.

~~~
dazbradbury
The issues were all "Web Sites" specific. I'm sure we could spin up machines
and get everything to run - but that's much less enticing compared to
AppHarbor / Beanstalk.

One example - if you have _any_ processing in the application_startup, Web
Sites won't work for you. Applications are randomly killed and restarted, and
don't allow for a startup time, meaning outages when this happens. Customer
support suggested using a fail over to work around this, but the fail over
only kicks in once your app has been down for a certain amount of time - so
you'll still have down time.

~~~
ghuntley
Push your AppStartup processing into a background worker?

a)
[https://github.com/HangfireIO/Hangfire](https://github.com/HangfireIO/Hangfire)
b) [http://azure.microsoft.com/en-
us/documentation/articles/web-...](http://azure.microsoft.com/en-
us/documentation/articles/web-sites-create-web-jobs/)

~~~
dazbradbury
What if your running app relies on the processing done during startup?

Sure - we could re-architecture the app so that isn't a requirement, but then
I'm making design decisions based on Azure constraints. Why would I when there
are alternatives like AppHarbor?

------
siganakis
We (msgooroo.com) use the .Net stack on Azure and have found it to be quite
good. We have even been experimenting with the new vNext / OWIN stack which
appears even better and will give us the flexibility to run on Linux.

Azure is a bit hit and miss. Its brilliant for getting something up an running
quickly (using websites / SQL Server), but is a little flaky at scale.

Key problems include connection issues with SQL Server, connection issues with
their hosted Redis service, pricing of SQL Server when using advanced features
like geo-replication.

All in all though, its a pretty good development experience once you get your
head around the fact that in the cloud services fail and there is nothing you
can do about it except plan for it.

Oh and the Bizspark program they have gives you $100 worth of free hosting on
Azure which is always nice.

~~~
taspeotis
> Key problems include connection issues with SQL Server,

What sort? If it's intermediate connection problems .NET 4.5.1 added
Connection Resiliency to ADO.NET [1]. If you're using a recent enough version
of Entity Framework it goes even further [2].

[1] [http://dpaoliello.wordpress.com/2014/03/30/connection-
resili...](http://dpaoliello.wordpress.com/2014/03/30/connection-resiliency-
in-ado-net-2/)

[2] [http://thedatafarm.com/data-access/ef6-connection-
resiliency...](http://thedatafarm.com/data-access/ef6-connection-resiliency-
for-sql-azure-when-does-it-actually-do-its-thing/)

~~~
ghuntley
[http://msdn.microsoft.com/en-
us/data/dn456835.aspx](http://msdn.microsoft.com/en-us/data/dn456835.aspx)

    
    
        public class MyConfiguration : DbConfiguration 
        { 
            public MyConfiguration() 
            { 
                SetExecutionStrategy( 
                    "System.Data.SqlClient", 
                    () => new SqlAzureExecutionStrategy(1, TimeSpan.FromSeconds(30))); 
            } 
        }
    

The above SqlAzureExecutionStrategy will retry instantly the first time a
transient failure occurs, but will delay longer between each retry until
either the max retry limit is exceeded or the total time hits the max delay.
The execution strategies will only retry a limited number of exceptions that
are usually tansient, you will still need to handle other errors as well as
catching the RetryLimitExceeded exception for the case where an error is not
transient or takes too long to resolve itself.

------
doobiaus
We're a start up using using .NET/C# MVC4 SQL Server etc etc. (Sorry can't
give names Just call us "Medical Software").

There are a lot more .NET start-ups than one is lead to believe, but you don't
hear so much about them because they're too busy making money to give
interviews to TechCrunch ;) Seriously though, they tend to be from developers
branching out of existing enterprises & "non-cool" fields and have existing
customers or bootstrap funding.

With Azure, AWS, Bizspark & MAPSDD cost implications of being on the .NET
stack are negligible comparing to the long term savings in maintainability.

------
Lelala
At Lelala ([https://www.lelala.de](https://www.lelala.de)), the MS stack with
the typical layers is used: \- IIS + ASP MVC \- MSSQL (via ORM layer) \- bunch
of .NET/C# tools & stuff to support the main system

Since it was asked what happens if the BizSpark period is over, let me state
on detail about the model: In BizSpark, its true that you go vendor lock in as
long as you are building strict dependency on their platform, lets say if you
use EF for accessing SQL, you may have a problem in the long run. But: Even if
you've left BizSpark, a MS Server License is to be paid _once_? (not per year,
not every two years etc.) I do not understand where the myth comes from that
one has to pay every year or continuously to use MS licenses? The math is
simple: A W2K12 Standard server license costs around 850 USD (~ 700 EUR) -
once - even if Opensource would is cheaper in term of license costs, a
software running 24/7 for a one-time payment of 700 EUR isn't that expensive.

Now, it comes down to scale up or scale out: \- in the one scenario, because
of no costs you can scale massivley out, going from one machine to n machines
\- but if you ever tried to administrate your machine park lonely(!!) if it
counts 5+ machines (while you have to develop/maintain & run the app itself,
too!), some may consider to hire a network admin (which is a fixed salary per
year which usually outweighs the costs of your MS Server license)

The reason why C# is used, is simple (and was stated above): \- C# and .NET
are very convenient and mature environments to write apps in \- C# is
considered by me as a beautiful language, i really like it (coming from x
years of "C-styled-syntax-languages" could make me somehwat biased ;-)

Instead of the licensing costs of MS products, i see much more important
difficulties in the mid- to long-run future if someone built on it: MS maybe
not survive the upcoming decade because of huge market shifts; then, in 10
years, it may be a problem if you will not get any support because the company
maybe no more existing. God thanks, the next version of ASP MVC has a VM for
*nix-derivatives, so you could solve this issue by running your app on a
Linux-box. (And if you then have built your app additionally on a top of an
ORM, you won't have any issues)

~~~
aleem
> Even if you've left BizSpark, a MS Server License is to be paid once?

Microsoft has a 3-year release cycle for their products. You'll end up paying
every three years. For every single product. Microsoft's biggest cash cows are
it's OS and Office products and always have been.

> A W2K12 Standard server license costs around 850 USD (~ 700 EUR)

Assuming you have just one server. At the least you will need a production
server and a development server. And at least one for every developer. That's
one OS license, one SQL Server license and one Visual Studio license per
developer. Personally, I love work with a lot of virtual machines off Vagrant
for development, testing and deployment. I am not sure how that works with MS
licences.

> if it counts 5+ machines [...] some may consider to hire a network admin

It's fairly easy to manage ~100 machines using Ansible, Docker, Chef, etc. But
in the Microsoft stack you probably want to keep the number of machines much
lower.

> scale up or scale out

Scaling up is the right approach on Windows platforms but here is the issue I
have with it. You cannot add RAM on the fly, as and when you need it. Nor can
you add more processor cores on the fly. With horizontal scale, it's a no
brainer but with vertical scale you cannot scale-up temporarily and then scale
back down either. This is quite common and desirable for web applications.

I was on BizSpark and I was really grateful for the free trial. However,
ultimately I shifted away and I am glad I did, even though C# is awesome and I
absolutely love Visual Studio, I moved away for a number of compelling
reasons.

~~~
duncanawoods
You can buy developer versions of sql server licenses. Last time I bought them
they cost £35 for the full enterprise package.

You can buy msdn packages for unlimited development use of any OS across VMs.
Around £600 / year I believe. More expensive MSDN subscriptions include
development OSes, Visual Studio & Sql Server at around £1000 / year.

------
frugalmail
Would love to see responses from the same users when the bizspark period is
over. Seems like an idiotic choice to go vendor lock-in, small community, IMO
sheltered mentality, high license fees (after bizspark), and difficult to
automate operating systems. I suppose if you don't need a lot of machines it's
not a problem yet, but seems like a lot of short sighted decisions.

~~~
jasonkester
I run S3stat and Twiddla on the .net stack and my BizSpark term has passed. It
was in no way a big deal.

Yeah, servers cost money to provision. But then servers always cost money to
provision regardless of your stack. Even with license fees, the MS stack wins
for me because my entire server farm fits on three boxes instead of the twelve
I'd need to get the same firepower on a typical rails stack. The extra few
thousand in full price server licenses is just noise because really, we're
talking about a business here, not a hobby.

The bottom line is that if your business is going to fail because of a single
$5,000 invoice, it's debatable whether it was ever a business to start with.
The whole reason we all build SaaS businesses in the first place is the 95%+
profit margins. Fretting about what happens within that 5% that makes up the
expense column seems a bit silly.

Even without BizSpark, I bet I'll build the next product on the same stack.
The math just plain works out.

------
skrebbel
At Izooble ([http://www.izooble.com](http://www.izooble.com) \- social product
recommendation site), our entire backend is written in C#. We use ServiceStack
(v3, which is still free) for our API, PostgreSQL for data.

We host it all on Mono and Docker on Linux VPSs. We wanted Docker because we
wanted PaaS-like deployment but not vendor lock in.

Our team uses Linux, Windows and OSX to work on it. MonoDevelop is a pretty
decent tool, on some areas actually better than VS.

We're really happy about the choice. C# is a great language, NuGet beats pip
and gem by miles (none of that virtualenv bull). If Mono support is a
requirement from the set-out, you don't run into many compat problems.

~~~
aleem
I really like that stack primarily because it couples c# with an open stack.
Could you share a bit more about the web server setup and how you came to
choose this stack?

~~~
skrebbel
Came to choose: It was the only language that doesn't suck that the entire
initial team had some to much experience with. About the open stack, seemed
obvious to me - why knowingly lock yourself in? BizSpark is nice, and we're
members, but not every startup takes off as fast as Slack and for a struggling
company, licenses might be prohibitive.

Server setup: We have 6 docker containers: Postgres, backend, nginx, assets,
data and ssh. Backend is a ubuntu+mono+backend_code. Data is the docker data
container pattern. Assets is the frontend code (we're an SLA). Ssh is an sshd
for looking at the data and logs in the data container.

Nginx and backend talk via fastcgi, one of ServiceStack's apphosts.

Currently it's all on one server, but the code is prepared for scaling and
load balancing.

------
woohoo7676
I'm using ASP MVC 5 with Knockout.js, hosted in Azure, for my startup
(commuting.io, still in dev). I've come from a .net background, so it seemed
like the easiest choice to get up and running.

Also using SQL Azure and Redis for data storage/caching - it's been mostly
positive so far. The downside with Azure has been the portal/management
experience. The current UI is somewhat sluggish and disorganized, and the new
portal tile UI is extremely confusing to navigate.

Overall it's been a pretty pleasant experience (maybe minus dealing with
web.config files).

~~~
vyrotek
_the new portal tile UI is extremely confusing to navigate._

Seriously. I don't know what they were thinking. I don't mind the current
portal. It does take seem sluggish with all the ajax/loading but at least I
know where everything is. The new portal needs to be completely redone.

------
arlattimore
Octopus Deploy [1], which is automated deployment software primarily for
deploying .NET applications is written in .NET. For those that have commented
about using Azure in their start-ups, you can use Octopus Deploy for that
also.

[1] [https://octopusdeploy.com](https://octopusdeploy.com)

------
Mandatum
Planning to launch a SaaS product full .NET stack running on Azure, BizSpark
gives you almost a year of free server time ($3700 worth, 9 months worth of
their biggest single VM uptime).

It's hard to say no when they give you so much free stuff for a startup-style
business.

~~~
Oculus
It's actually pretty easy once you realize that you have to pay for the
licences on all Microsoft technologies once BizSpark ends. It gives just
enough time to be too locked in to easily adopt a different technology stack.

~~~
hayksaakian
can you run linux VMs on azure? i think so.

free servers are free servers.

~~~
cpayne
Microsoft have gone out of their way to support everything!

[http://azure.microsoft.com/en-
us/documentation/articles/virt...](http://azure.microsoft.com/en-
us/documentation/articles/virtual-machines-linux-endorsed-distributions/)

[http://azure.microsoft.com/en-us/pricing/details/virtual-
mac...](http://azure.microsoft.com/en-us/pricing/details/virtual-
machines/#Linux)

------
raphinou
Honest question: what are the advantages of this choice? I have horrible
memories from the time i used microsoft software. Iirc iis had horrible
logging, windows administration is not easy to be scripted (is there an ssh
server/client by default?), you can be left alone if ms changes course (as has
happened in the past), etc I personally feel much safer and efficient by
avoiding ms, but curious to learn and hear counter arguments.

~~~
_random_
You seem to be coming from an admin/ops perspective.

From developer's perspective it's two modern mainstream languages - F#, C# -
that can be used on Windows, Azure, Mac, iOS, Android, WP as a well-defined
workflow.

The best IDE - Visual Studio + ReSharper + soon Roslyn. Second best ecosystem
of libraries, that is picking up.

There are some missing bits that are coming: docker and containers, dynamic
compilation (of static typed code) when building web sites.

It might not be the best choice in individual "disciplines", but it's the best
overall.

------
santoriv
We are using .Net MVC with C#/Typescript at Makemake.io (still in dev) on
Azure. The biggest benefit for our project is Visual Studio and Resharper's
Typescript support - it's _really_ helpful for writing big Typescript apps
(right now we have 400+ Typescript files in our SPA).

Bizspark is also great! $150 per month of free credit really helps -
especially at the early stages.

~~~
zerr
What frameworks/libs you use in TypeScript?

~~~
santoriv
Ember, Pixi, When, jQuery. That's pretty much it. All of them have type
definitions (although some are a bit out of date/inaccurate).

------
taspeotis
The project I work on isn't a startup per se but it's not completely
dissimilar. We use:

* ASP.NET for web with SQL Server + EF for the database and data access

* Xamarin for mobile and OData for data access (back to our ASP.NET sites)

The CLR is great because it's always been fast enough for our applications and
every so often you get something for nothing. For example, CLR 4.5 brought
better GC and RyuJIT is bringing better code generation. NET Native might give
us even better performance.

LINQ is amazing if you know your IQueryables from your IEnumerables and the
difference between an Expression<Func<T, bool>> and a Func<T, bool>.

Hosted in a private datacentre, not using Azure but we've got our eye on it
(provisioning resources in the Azure Portal seems to get easier and easier
than doing it ourselves).

New Relic for monitoring the web sites.

My biggest gripe (and it's not that big) is that within the Microsoft
ecosystem/community everything works great but once you go outside it things
are less well supported. Some less-popular-but-wow-that's-useful Javascript
libraries don't come as NuGet packages. New Relic's .NET monitoring seems good
but second fiddle to their other stuff.

After that I'd say Xamarin is letting the team down. Every second or so
release of theirs fixes two bugs but adds another one.

Keeping an eye on Application Insights. It looks like it integrates nicely
with Visual Studio Online, and VSO/TFS actually looks quite nice _in parts_
(e.g. Bamboo for CI is largely geared towards Java apps not .NET but TFS'
Release Management looks promising). I have my eye on VSO/TFS too but right
now it looks like pros do not outweight the cons vs. our Atlassian
applications.

If you've got enough processing power and memory and a fast SSD to run Visual
Studio + ReSharper it's coding heaven.

~~~
_random_
_> "Some less-popular-but-wow-that's-useful Javascript libraries don't come as
NuGet packages"_

The good will become perfect soon enough:

[http://www.hanselman.com/blog/IntroducingGulpGruntBowerAndNp...](http://www.hanselman.com/blog/IntroducingGulpGruntBowerAndNpmSupportForVisualStudio.aspx)

------
Permit
We're using it at Code Connect
([http://codeconnect.io](http://codeconnect.io)). We build a plugin for Visual
Studio, so there's not exactly a lot of choice. :)

Personally, I've always enjoyed C#, so it's been a pretty positive experience
on the whole.

------
michaelsbradley
Any .NET folks making use of ClojureCLR?

[https://github.com/clojure/clojure-clr](https://github.com/clojure/clojure-
clr)

~~~
grayrest
Survey says probably not:

[https://cognitect.wufoo.com/reports/state-of-
clojure-2014-re...](https://cognitect.wufoo.com/reports/state-of-
clojure-2014-results/)

There was an announcement of Clojure in Unity3d [1] a couple weeks ago which
is ClojureCLR.

[https://github.com/arcadia-unity/Arcadia](https://github.com/arcadia-
unity/Arcadia)

------
benhamner
We use C# and F# extensively at Kaggle: kaggle.com is an ASP.NET MVC app on
Azure, and a good portion of our data processing is in C# or F#.

------
photon137
Using a cluster of Owin (self-hosted) servers with NancyFx on Mono to host
REST APIs behind nginx for a distributed-computing solution on AWS. Also use
EntityFramework on Npgsql+postgres - experience has been positive.

Only downside is that for something like a customer-facing portal, the
identity-management is tied to Windows-specific features, for now - so have
had to build a custom solution for this that runs on Linux. Waiting for ASP
.NET vNext and its Identity solution when it becomes slightly more mature.

EDIT: Also evaluating a move to Azure. Primary driver (for choosing the .net
stack) has been prior experience with C#, .NET and Visual Studio

------
kimura
At [http://www.listmax.ca](http://www.listmax.ca) we use .NET for our backend
api and various other tasks. Plentyoffish ran .NET stack on one machine for a
very long time.

------
carsongross
Xero is built on the .NET stack. Per Craig Walker (CTO):

    
    
      https://www.xero.com/blog/2011/03/why-we-hire-any-kind-of-programmer/
    

"Xero is a .NET shop."

------
thnetcoder
I use the .net stack for every project.

[http://pitsolutions.io/](http://pitsolutions.io/)

All .net/sql server, jquery on the front end with websockets.

------
redact207
Our tech stack at Entomic (www.entomic.com) is all done in .NET. We've got a
pretty common stack (at least we think so) - MVC5, WebAPI, SignalR running on
Azure web and storage.

Like others here who get set up on a MS stack, everything integrates very
easily. Visual Studio IMO is still one of the best IDEs out there for what it
does, and having that supported by a good CI system means very little is left
to do except code.

------
mark_l_watson
This will be a little off topic since the last time I tried C# and .Net was
many years ago (I was getting prepped to write a book on J2EE, and I wanted to
spend a week using the competition first, to get a more balanced point of
view):

I want to praise Microsoft's BizSpark program. I was accepted a few months ago
after I submitted my plan for a SaaS product. I am using Ubuntu servers on
Azure, and Azure works well - fewer services than AWS, but a comparable
developer's experience to AWS and Google's offerings. I definitely recommend
looking into BizSpark if you are interesting in developing an SaaS business.
Since I am using Linux, Haskell, and Ruby I am not really locked into using
Azure, but if my SaaS product is successful, I will probably keep using Azure
in gratitude for $150/month of free Azure use for up to 3 years.

In general my attitude about Microsoft improved a lot earlier this year after
trying their Office 360 product that works on all of my devices (MacBook,
iPad, and Android phone). I like the direction the new CEO is taking the
company.

------
profquail
I know of at least two startups who're heavily using F#:

[http://tachyus.com/](http://tachyus.com/) [http://jet.com/](http://jet.com/)

There are others as well (I just don't recall their names right now) -- take a
look on [http://fsharp.org](http://fsharp.org) for more links.

------
cpayne
[https://www.moneysoft.com.au](https://www.moneysoft.com.au) \- is a running
on C# & SQL Server , hosted on our own servers.

And [https://www.calendartree.com/](https://www.calendartree.com/) (startup by
Dilbert's Scott Adams + others) are C# / SQL site, on their own servers.

~~~
quink
Anyone else getting ERR_CERT_AUTHORITY_INVALID?

~~~
pope13
Not getting the exact error, but the cert that
[https://www.moneysoft.com.au](https://www.moneysoft.com.au) is using is not
actually for [https://www.moneysoft.com.au](https://www.moneysoft.com.au).

~~~
cpayne
Sorry, getting our app and website mixed up.

Website: [http://www.moneysoft.com.au/](http://www.moneysoft.com.au/) App:
[https://secure.moneysoft.com.au/](https://secure.moneysoft.com.au/)

------
webwright
Everymove in Seattle is, I believe.

[https://everymove.org/](https://everymove.org/)

------
dmarlow
We, at Degreed ([https://degreed.com](https://degreed.com)), are using .NET,
MVC 5, EF 6 on Azure. Front-end is Angular. We are part of BizSpark Plus which
ends next month. Currently looking into whether or not VS 2013 Express for Web
is sufficient.

Reason for using it was tooling, hosting and familiarity. I enjoy being able
to being able to fully debug the code and step through things. Makes things
enjoyable, to say the least. I love C# and use it for everything I do.

Only concern is the steep SQL pricing for the new tiers and the occasional
blips as mentioned by siganakis. However, support is fast and helpful.

Shameless plug: we're hiring. We're distributed/remote between SF, SLC and LA.
Ping me for futher details.

Disclaimer: former MS dev.

------
everettForth
The question reminded me of this classic:
[http://blogs.law.harvard.edu/philg/2009/05/18/ruby-on-
rails-...](http://blogs.law.harvard.edu/philg/2009/05/18/ruby-on-rails-and-
the-importance-of-being-stupid/)

------
vyrotek
[http://iactionable.com](http://iactionable.com) is a .NET/C# start-up. We're
completely hosted in Windows Azure as well. We also went through the Microsoft
BizSpark program which is amazing and I highly recommend it.

------
fmavituna
We are using .NET Stack for our web app scanner. Both for desktop and
([https://www.netsparker.com/web-vulnerability-
scanner/](https://www.netsparker.com/web-vulnerability-scanner/)) and SaaS
versions use .NET ([https://www.netsparker.com/online-web-application-
security-s...](https://www.netsparker.com/online-web-application-security-
scanner/))

We started with Bizspark as well, now we graduated and license cost is not
much really. We also rely on MS stack for many things other than source code
repository / CI etc.

------
zeeshanm
ZocDoc in NYC uses C#/.NET stack.

------
ayrx
Stack Exchange is a .NET shop as well.

~~~
ooOOoo
For details, see [http://meta.stackexchange.com/questions/10369/which-tools-
an...](http://meta.stackexchange.com/questions/10369/which-tools-and-
technologies-are-used-to-build-the-stack-exchange-network)

------
architgupta
ClearTax -- cleartax.in uses the .net stack. We use F# and C#.

------
math
we use it extensively at
[http://www.backrecord.com](http://www.backrecord.com) (C#, mono)

------
atko
We're a startup ([https://whoaverse.com](https://whoaverse.com)) using
.NET4.5/C# MVC5 and SQL, currently working on getting set up in Switzerland.
C# beauty, Visual Studio and Azure were the key factors why we decided to go
with .NET.

------
Aaronontheweb
We ([https://markedup.com/](https://markedup.com/)) use C# heavily and do
about 20-30k requests per minute on fairly small Elastic Beanstalk / EC2
instances.

Mostly ASP.NET MVC, but we also use Akka.NET for a lot of our internal
services.

------
graycat
We are using Windows, the .NET Framework, IIS, ASP.NET, and Visual Basic .NET.
We're on the .NET Framework 4.0 and see no reason to move to 4.5.

For C#, not interested: The syntax borrows from the deliberately
_idiosyncratic syntax_ of C, and the Visual Basic syntax is more verbose,
easier to learn, teach, and read, and, thus, less error prone, is as a
programming language in its semantics, features, and functionality essentially
equivalent to C#, that is, the difference is mostly just _syntactic sugar_ ,
and apparently is about as good as C# or anything else at getting at the CLR
and the .NET Framework.

For F#, people back to Backus have been working on functional programming,
and, for more than just curiosity, and certainly for the work of our start-up,
we're not impressed or interested, in that or logic programming, rule-based
programming, or standing on our heads in the corner programming, etc. -- sorry
'bout that; we can agree to disagree, and YMMV.

We're quite pleased with Visual Basic .NET. A hat tip to the Microsoft Visual
Basic group.

Main gripe: For the documentation, actually for all the documentation on MSDN,
especially for SQL Server, please, please, please, get a least a C in
technical writing 101. Our biggest problem in our start-up, far and away,
much, much, much more difficult than everything else combined, literally, is
the low quality of the technical writing at MSDN.

For JavaScript, Microsoft's ASP.NET writes some for us, but so far we have yet
to write a single line of it and will delay doing so as long as we can,
hopefully forever.

For ASP.NET, we are using just the basics, that is, with

    
    
         Sub Page_Init
         Sub Page_Load
         Sub Page_PreRender
         Sub Page_Unload
    

etc. We have heard of MVC, looked at it a little, can see no reason for it or
advantage in it, and intend to have nothing to do with it. Maybe better
technical writing at MSDN would let us take MVC more seriously.

We type into our favorite text editor and make no use of an IDE nor do we want
to.

For developing code for Web pages, ASP.NET and Visual Basic work nicely
together \-- it works fine. Actually, it's nice.

For a session state store, we wrote our own using just instances of one class,
de/serialization, TCP/IP _raw_ sockets, and two collection classes. On an 8
core processor at 4.0 GHz, our session state store should be good for 11,000+
transactions a second; _transactions_ is appropriate because the code is
single threaded. Yes, on an 8 core processor we would run several instances
with _sharding_.

As we go live, our server will be just a single full tower case with an 8 core
processor, 32 GB of main memory, some SSDs for a special purpose particular to
our start-up, and some disks, with Windows Server, SQL Server, IIS, ASP.NET,
our Web pages, our session state store, and some specialized back-end servers.
The software and architecture are scalable via just simple _sharding_. We have
little or no intention of using the cloud soon or ever.

As we go live and grow, after the issue of the MSDN documentation, no doubt,
and closely related to the documentation issue, our biggest concern will be
Windows Server, SQL Server, and IIS installation, configuration, updates,
security, monitoring, management, performance, administration, reliability,
backup, and recovery -- little things like those. But from some of the just
astounding successes Microsoft has running server farms with their software,
clearly terrific results are possible; maybe we will be calling for some high
end technical support.

That's what we are doing!

~~~
angersock
You're trolling, right? Please?

...if not, would you mind letting us email your developers to try and save
them from career suicide?

~~~
graycat
Trolling? Not at all. Instead, it's just what we are actually doing.

I'll let them all know that they have a choice: (1) Make money doing the work
to make our software and Web site good, our users happy, and our start-up
successful or (2) grow their resumes for jobs elsewhere.

With (1), they get to help build something important. With (2) they get to add
buzz words of questionable utility for unknown projects of questionable value.
YMMV.

------
DanielBMarkham
I've been using F# on Mono for all of my startup back-end work over several
startup attempts.

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RobotCaleb
What are you doing with this list?

~~~
nirajs
Thanks. Basically, creating a network of startup folks to help each other with
tools and ideas. Job board to find talents. We also make
[https://dotnetfiddle.net/](https://dotnetfiddle.net/) to collaborate, help
educate all things .net

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dgudkov
We use C#/F# for enterprise data processing app. C# for WPF front-end and F#
for data processing back-end. F# was a total revelation for me and it has
become my favorite programming language.

------
Immortalin
Contemplating on whether should I use ASP.Net webforms for my ecommerce site
or stick with a no/minimum-coding required solution such as wordpress/drupal

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WorldWideWayne
I'm using Node.js + .NET for my part-time, single founder startup.

