Today, a courier cyclist arrived bearing the gift of a new contract for new employment. If everything goes as expected we'll be working in the City within two weeks.

It's perhaps better not to mention the employer by name but they're a solutions provider working within an interesting area of finance and our role's likely to involve helping to ensure the reliability of systems processing terrabytes of data with issues of cleanliness and performance being most important. We're thinking optimised data querying, concurrency (scale) and transformation/calculation.

Without much recent UI experience all the cool Winforms & Web developer roles seemed out of reach so this is where our spare time needs to be invested over the next couple of years whilst the day job is all about the data, touching possibly on F# and elements of grid computing and much more of the modelling languages: UML & XML.

In terms of development approach the experience from the last consultancy role at Man Investments should prove invaluable in terms of transferring agile methodology and process where appropriate but because this is a smaller company, enterprise systems integration complexity ought not to present the same kind of challenges. I'm hoping for a more contained, bounded, intra-application kinda complexity. Those woods and trees managed to get quite blurred in that last assignment.

The new mission is to help provide Market Transparency.

I should add that Man Investments was a fantastic place to work.

Yesterday, during yet another interview, we didn't deliver quite  the finest explanation of what an XML Namespace is. Today, we're using them to parse a Stack Overflow feed so clearly we understand them, however, if part of the question's purpose is to assess our ability to express this simple idea simply then shitehawks! #fail

Take this feed, for example, which is the RSS for a useful post on Volatile vs. Interlocked vs. lock. In order to to be able to use XPath with XDocument to retrieve the question we rely on XmlNamespaceManager.

    var xDoc = XDocument.Load("http://stackoverflow.com/feeds/question/154551");

    var xmlNamespaceManager = new XmlNamespaceManager(new NameTable());
        xmlNamespaceManager.AddNamespace("atom", "http://www.w3.org/2005/Atom");

    var postedQuestion 

        = xDoc.XPathSelectElement("/atom:feed/atom:entry/atom:summary", xmlNamespaceManager);

This is another example of Stack Overflow brilliance. The feeds are in chronological order so that we can guarantee that the first item (or entry) is the original post. Following the Volatile trail leads to a Joe Duffy post on Volatile Reads and Writes, and Timeliness. For example, he writes the C# documentation for volatile is highly misleading with reference to the following MSDN documentation:

The volatile modifier is usually used for a field that is accessed by multiple threads without using the lock statement to serialize access. Using the volatile modifier ensures that one thread retrieves the most up-to-date value written by another thread.

Unfortunately, I can't find this specific RSS item within the Technology feed and the same is true for the RSS feed for this blog. Although it's possible to score a reference to the item if it appears within the list of entries as they each have a unique ID, should the category contain too many entries then the older posts don't show up. Soon I'll show why this might matter but I digress.

We interviewed with a London-based Hedge Fund last Friday and, as usual, it was interesting. The first guy I saw (head of development) is a graduate of Conchango, a company that writes software of excellent quality using good developers, the latest software technology and techniques, etc. Also, they often kindly host the London Dotnet User Group meetings at their offices near London Bridge.

Naturally the interviewer asks fair questions along the lines of Value Types versus Reference Types and Garbage Collection. Inheritence and Shadowing. So far so good. Only when we get to the Messaging architecture used and extended at the previous client's site is there a little uncertainty. Without the source code, which we didn't take with us, we can't remember enough detail about the implementation from July 2008 so there's one shaky answer.

Next up is a question about our exposure to SQL Server 2005. Yup, we used it. Oh, which bits? That will be the new Try-Catch (after a little prodding about error-handling). We mention not having used CLR functions but being aware of the possibility which leads to a question about the components of the CLR... and we've a blank moment!

The JIT compiler! In fact we mentioned just JIT.

This is *all* that arrives. That's it. Nothing about Exception-Handling, Memory Management, Thread Management, Garbage Collection, Security, Managed Code, Type Safety - this is an impressive list already - Portable Executables nor IL never mind debugging and profiling services offered. Oh, there's more that wasn't mentioned. Code management (loading and execution), Application memory isolation, Access to metadata (enhanced type information) and Interop. Nice.

Then comes the first of a few quirky incidents. Hint: If ever an interviewer testing your C# knowledge offers the Base Class Library as a component of the CLR it's probably worth saying something. To prevent an already lengthy entry from growing needlessly still a summary will do here. When Interviewer #1 is replaced by a senior developer I then learn that impersonation does not work the way I've used it. Apparently, I've misundersood all along that using the identity element in the web config for an ASP.NET web application will not allow me to use credentials for a SQL Server connection. Maybe at that point I should have just looked it up on my iPhone and shown him this:

<system.web>
    <identity impersonate="true" userName="domain\username" password="password" />
</system.web>