Most important question of your interview

I always finds it interesting how the questions answered by an interviewer are evaluated. 

Always deciding factor could be one question. What if the question is "Do you have any questions for us?"

I personally was asked this question in all interviews. Which makes this common and important. Let’s get to the answers that make differences.

• What is the immediate need on your team that you are hoping to fill with this position?
• What projects can I contribute to right away?
• Is this team empowered to find better and more efficient ways to do things?
• Can you tell me how your organization defines success?
• How would you describe a typical day on this team?

These questions will show the interview that your unique, committed and contributor.

Source: http://lifehacker.com/5935550/the-interview-question-that-is-always-asked-and-how-to-nail-it

Be different from developer next to you

What every software developer, project leaders, architects, system support people should know.
1. Understanding basic operating system, memory management, I/O etc.
2. Through understanding of Disk IO.
3. TCP/IP, HTTP protocol and how it works.
4. Good understanding of database.
5. How programming language works? Build your own toy language in your favorite language if possible. This may not be production quality, but will involve a lot of learning points.
6. Thorough understanding of object oriented programming, functional programming.
7. Client side scripting foundation
8. Data structures
9. Design patterns
10. Foundational maths (not advanced maths)
11. Basic physics (most useful for game programmers and interaction designers).
12. Economics (will be useful if you need to startup your own venture and understand the demand/supply in the market)

Ref: http://geekswithblogs.net/rajeshpillai/Default.aspx

Handling a million requests is challenging

I recently watch a video on youtube from Omar Al Zabir, where he present lot of interesting fact and preventive step that can be taken

http://www.youtube.com/watch?v=wHdvL4irsiQ&

I gonna bring the summary here and more finding from my experience

• Preventing DOS attacks.

We all know that DOS is famous attack and it is very easy to implement and which can be achieved sending 1000 of requests in constantly and webserv

er that handles the request goes out of threads and CPU usage hits max and webserver goes down.

So the way we can prevent this by implement a HttpModule and on OnInit event track the IP address of the requestor and terminate the connection as early as possible after reaching certain limit. (Response.End())

• ASP.NET ProcessModel optimization.

Microsoft set the default values to

1. maxWorkerThreads = 20

2. maxIOThreads = 20

3. memoryLimit = 60

These values old and are give when CPU's Single Processors, so increasing these values will make webserver to handle more request will less CPU overhead.

so maxWorkerThreads and maxIOThreads can be increased to 100 and memoryLimit can also be increased.

• ASP.NET pipeline optimization

There are set default httpModules in machineConfig that every request go through all these httpModules, which is unnecessary overhead.

so assuming some default these can be removed from our applica

tion web.config

1. windowsAuthentication

2. PasspostAuthentication

3. AnonymousIdentification

3. FileAuthorization

4. UrlAuthorization

eg: Preventing ASP.NET Large cookies on Static Pages

• System.Net optimization

If there are any HttpWebRequest or WebClient (WCF) calls incr

ease the maxConnections limit which present in connectionmanagment configuration. By Default one IP can send only 2 concurrent requests.

• Optimize the ASP.NET Profile and Membership provider.

When making request to the Profile or Membership tables could be expensive. We might need to reduce the isolation levels on the some dbo. stored procedures and all the columns not indexed. (Need more writing here.)

• HTTP Compression

With IIS 7 provides the build-in compression available from the web.config. Add this to the web.config

<urlCompression doDynamicCompression="true" doStaticCompression="true" dynamicCompressionBeforeCache="true" />

• Cache Static files

Browser will cache files such as images, stylesheets and script files. By letting the browser cache all these files means it doesn’t need to request them again for the duration of the cache period.

<staticContent>
<clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="365.00:00:00"/>
</staticContent>