https://www.kalapos.netAbout programming and software engineering by a hungarian living in austriaen-usCopyright 2014-2026 Gergely KalaposSun, 21 Oct 2018 19:00:00 GMTSoftware Engineeringhttps://kalapos.net/images/GergelyKalapos.small.jpghttps://www.kalapos.net40I’m in the middle of switching jobs, so recently I had the opportunity to talk to a couple of companies. “Job interviews” was always a topic that I was very interested in, so I thought I summarize what I had learned over the years in a blogpost.https://kalapos.net/Blog/ShowPost/developer-interviews.htmlgergo@kalapos.net (Gergely Kalapos)Sun, 21 Oct 2018 19:00:00 GMTdeveloper-interviews.html#When10/21/201819:00:00In this episode we talk about 'ref structs', which was introduced in C# 7.2. You will learn what it is, where it is used in the framework and when you should use it in your own code.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek16-RefStructgergo@kalapos.net (Gergely Kalapos)Fri, 03 Aug 2018 17:32:00 GMTDotNetConceptOfTheWeek16-RefStruct#When08/03/201817:32:00In this episode we create a "Not Hotdog" clone from Silicon Valley (HBO) called "SchnitzelOrNot" with .NET and AWS. For this we use AWS Lambda with .NET Core, S3, and Amazon Rekognition.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek15-awsgergo@kalapos.net (Gergely Kalapos)Tue, 24 Jul 2018 17:32:00 GMTDotNetConceptOfTheWeek15-aws#When07/24/201817:32:00I published a new course on Udemy. In this post I write a little bit about the course itself and I also give a few “behind the scenes” details about how such a course is made.https://kalapos.net/Blog/ShowPost/Udemy-Advanced-DotNet-Coursegergo@kalapos.net (Gergely Kalapos)Fri, 06 Jul 2018 17:32:00 GMTUdemy-Advanced-DotNet-Course#When07/06/201817:32:00In this episode we talk about exception filters in C#. We will take a look at the generated IL code and we will also discuss that entering a catch block always unwinds the stack, which makes debugging harder and also can hurt performance. With an exception filter we can avoid this!https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek14_CSharpExceptionFiltersgergo@kalapos.net (Gergely Kalapos)Fri, 25 May 2018 21:18:00 GMTDotNetConceptOfTheWeek14_CSharpExceptionFilters#When05/25/201821:18:00In this episode I talk about struct layout in C#. You will learn how C# structs are represented in memory and you will also learn how you can influence this with StructLayoutAttribute.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek13_DotNetMemoryLayoutgergo@kalapos.net (Gergely Kalapos)Fri, 11 May 2018 16:22:00 GMTDotNetConceptOfTheWeek13_DotNetMemoryLayout#When05/11/201816:22:00In this episode we take a look at the changes in the ASP.NET Core Module (ANCM) in 2.1. ANCM is the IIS module that we need to host ASP.NET Core apps in IIS.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek12_ANCMgergo@kalapos.net (Gergely Kalapos)Mon, 23 Apr 2018 21:52:00 GMTDotNetConceptOfTheWeek12_ANCM#When04/23/201821:52:00In this episode I talk about SIMD in .NET. We take a look at the Vector type from the System.Numerics namespace and I show you how you can tell RyuJIT to generate SIMD instructions with this Vector type.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek11_Simd_Vectorizationgergo@kalapos.net (Gergely Kalapos)Tue, 27 Mar 2018 21:17:00 GMTDotNetConceptOfTheWeek11_Simd_Vectorization#When03/27/201821:17:00In this episode we take a look at docker in combination with ASP.NET Core and Visual Studio.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek10_DockerAndAspNetCoregergo@kalapos.net (Gergely Kalapos)Sun, 18 Mar 2018 22:18:00 GMTDotNetConceptOfTheWeek10_DockerAndAspNetCore#When03/18/201822:18:00In this episode we take a look at WebAssembly and Blazor. You will learn what WebAssembly is, and we will write C# code that we will execute in the browser with Blazor on top of WebAssemply.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek09_WebAssembly_Blazorgergo@kalapos.net (Gergely Kalapos)Mon, 05 Mar 2018 00:03:00 GMTDotNetConceptOfTheWeek09_WebAssembly_Blazor#When03/05/201800:03:00In this episode we take a look at ASP.NET Core SignalR. I show how you can create a real time chat application with a few lines of code with the help of SignalR.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek08_SignalRgergo@kalapos.net (Gergely Kalapos)Wed, 28 Feb 2018 18:48:00 GMTDotNetConceptOfTheWeek08_SignalR#When02/28/201818:48:00Yesterday we had our 4. .NET meetup in Linz. Since it seems to become a thing that people recognize as a "regular meetup in town" I thought it's time to write about it!https://kalapos.net/Blog/ShowPost/HowToOrganizeADotNetMeetup_9Tipsgergo@kalapos.net (Gergely Kalapos)Wed, 21 Feb 2018 18:24:00 GMTHowToOrganizeADotNetMeetup_9Tips#When02/21/201818:24:00In this episode I show you a few very cool features in F#. This is an intro video intended for .NET programmers who want to learn about functional programming and wonder what F# can offer.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek07_FSharpgergo@kalapos.net (Gergely Kalapos)Mon, 19 Feb 2018 20:12:00 GMTDotNetConceptOfTheWeek07_FSharp#When02/19/201820:12:00In this episode you will see how you can outsource authentication to Facebook and Twitter in ASP.NET Core.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek06_AspNetCoreFacebookAndTwitterLogingergo@kalapos.net (Gergely Kalapos)Sun, 11 Feb 2018 22:36:00 GMTDotNetConceptOfTheWeek06_AspNetCoreFacebookAndTwitterLogin#When02/11/201822:36:00In this episode I talk about BenchmarkDotNet.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek05_BenchmarkDotNetgergo@kalapos.net (Gergely Kalapos)Mon, 05 Feb 2018 21:53:00 GMTDotNetConceptOfTheWeek05_BenchmarkDotNet#When02/05/201821:53:00This time I explain what covariance and contravariance are. You will learn about covariance and contravariance with delegates, arrays, and generic interfaces.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek04_CSharp_CovarianceAndContravariancegergo@kalapos.net (Gergely Kalapos)Sun, 28 Jan 2018 22:52:00 GMTDotNetConceptOfTheWeek04_CSharp_CovarianceAndContravariance#When01/28/201822:52:00In this episode I show you the preview C# 8 compiler and we talk about a very interesting proposal for C# 8 called nullable reference typeshttps://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek03_CSharp8_NullableReferenceTypesgergo@kalapos.net (Gergely Kalapos)Mon, 22 Jan 2018 19:23:00 GMTDotNetConceptOfTheWeek03_CSharp8_NullableReferenceTypes#When01/22/201819:23:00The second video form my new thing is out! In this short video I show you how you can use WebSocket in a .NET Standard library and then we will use this .NET Standard library in a UWP and in a Xamarin.iOS app.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek02_WebSocket_Xamarin_UWPgergo@kalapos.net (Gergely Kalapos)Sun, 14 Jan 2018 21:54:00 GMTDotNetConceptOfTheWeek02_WebSocket_Xamarin_UWP#When01/14/201821:54:00I decided to start something new! I will create a video every week, where I explain a concept related to .NET programming. The first video is out! It’s about CancellationToken and task cancellation.https://kalapos.net/Blog/ShowPost/DotNetConceptOfTheWeek01_CancellationToken_TaskCancellationgergo@kalapos.net (Gergely Kalapos)Sun, 07 Jan 2018 21:12:00 GMTDotNetConceptOfTheWeek01_CancellationToken_TaskCancellation#When01/07/201821:12:00I have a part in my 'High performance Coding with .NET and C#' Udemy course that is basically a stand-alone section. I uploaded it to YouTube and in this blogpost, you can watch the videos in order. It's about performance related features in C# 7.https://kalapos.net/Blog/ShowPost/CSharp7_Perf_Playlistgergo@kalapos.net (Gergely Kalapos)Sun, 07 Jan 2018 14:40:00 GMTCSharp7_Perf_Playlist#When01/07/201814:40:00I recently published an online course (yeaah)! In this post I would like to share the background story.https://kalapos.net/Blog/ShowPost/Udemy_HighPerformance_DotNetCoregergo@kalapos.net (Gergely Kalapos)Mon, 04 Dec 2017 22:13:00 GMTUdemy_HighPerformance_DotNetCore#When12/04/201722:13:00I decided to try a new format! In a screencast I show you how I created a CI/CD pipeline for an ASP.NET Core application that runs on a Linux server and how you can have a similar setup!https://kalapos.net/Blog/ShowPost/cicdpipelinescreencastgergo@kalapos.net (Gergely Kalapos)Sat, 12 Aug 2017 20:53:50 GMTcicdpipelinescreencast#When08/12/201720:53:50I created a small F# application on .NET Core which tries to help to figure out if it makes sense to invest into the stock market when it is at its all-time high. This post is about the technical details of this small program and of course I will also talk about my results.https://kalapos.net/Blog/ShowPost/BackTestingWithFSharpgergo@kalapos.net (Gergely Kalapos)Mon, 24 Jul 2017 08:13:50 GMTBackTestingWithFSharp#When07/24/201708:13:50ASP.NET Core 2.0 introduced a new interface called IHostingStartup and a few interesting environment variables like DOTNET_ADDITIONAL_DEPS and ASPNETCORE_HOSTINGSTARTUPASSEMBLIES.This post shows how Application Insights takes advantage of them and how you can also use them.https://kalapos.net/Blog/ShowPost/IHostingStartupInAspNetCore20gergo@kalapos.net (Gergely Kalapos)Tue, 06 Jun 2017 08:13:50 GMTIHostingStartupInAspNetCore20#When06/06/201708:13:50This post is a recap of the second day of Build 2017https://kalapos.net/Blog/ShowPost/Build2017Day2gergo@kalapos.net (Gergely Kalapos)Thu, 11 May 2017 08:13:50 GMTBuild2017Day2#When05/11/201708:13:50This post is a recap of the first day of Build 2017https://kalapos.net/Blog/ShowPost/Build2017Day1gergo@kalapos.net (Gergely Kalapos)Wed, 10 May 2017 08:13:50 GMTBuild2017Day1#When05/10/201708:13:50While working on a side project I created a netstandard compatible F# library, which basically calculates different technical analysis indicators for input data. This is mostly useful for technical stock analysis. I decided to open-source the library. This post shows what the library can do and how you can use it.https://kalapos.net/Blog/ShowPost/MyTradesAnalytics-a-netstandard-compatible-technical-analysis-librarygergo@kalapos.net (Gergely Kalapos)Fri, 09 Dec 2016 05:00:00 GMTMyTradesAnalytics-a-netstandard-compatible-technical-analysis-library#When12/09/201605:00:00This is an update of my project.json settings post, which describes the same settings in the new .csproj filehttps://kalapos.net/Blog/ShowPost/csproj-settings-in-aspnet-coregergo@kalapos.net (Gergely Kalapos)Sun, 20 Nov 2016 20:59:00 GMTcsproj-settings-in-aspnet-core#When11/20/201620:59:00The official documentation for hosting on Linux only describes how to host ASP.NET Core apps behind nginx. Here is a short summary about the same for Apache.https://kalapos.net/Blog/ShowPost/hosting-aspnetcore-on-apachegergo@kalapos.net (Gergely Kalapos)Tue, 18 Oct 2016 05:21:00 GMThosting-aspnetcore-on-apache#When10/18/201605:21:00Finally, I managed to move my blog! This post is just a short technical summary about it.https://kalapos.net/Blog/ShowPost/moving-the-bloggergo@kalapos.net (Gergely Kalapos)Sun, 16 Oct 2016 12:32:00 GMTmoving-the-blog#When10/16/201612:32:00This blog is about programming and software engineering and this post may look like yet another "how to be healthy and happy" blog at the first glance, but it is not! I think being productive is very important, especially if you are in the software business. And this post is all about productivity!https://kalapos.net/Blog/ShowPost/my-developer-productivity-tip-runcommutegergo@kalapos.net (Gergely Kalapos)Wed, 21 Sep 2016 03:08:00 GMTmy-developer-productivity-tip-runcommute#When09/21/201603:08:00Aaaand a post again, which will be deprecated at some point: currently using both F# and C# in a .net core solution is possible, but needs some workaround. Here I describe how you can do ithttps://kalapos.net/Blog/ShowPost/referencing-an-f-library-from-c-on-net-coregergo@kalapos.net (Gergely Kalapos)Sun, 03 Jul 2016 08:13:50 GMTreferencing-an-f-library-from-c-on-net-core#When07/03/201608:13:50I have a side project which I started at the beginning of this year. One of the top goals of this project is to learn new things and i'm still at the beginning of this, but I already have many things working.https://kalapos.net/Blog/ShowPost/working-with-net-core-my-summary-after-5-6-months-with-asp-net-core-on-a-side-projectgergo@kalapos.net (Gergely Kalapos)Mon, 27 Jun 2016 19:59:39 GMTworking-with-net-core-my-summary-after-5-6-months-with-asp-net-core-on-a-side-project#When06/27/201619:59:39Asp.net core RC2 was officially released a few hours ago. I have a side-project, which I did not update until this point, so I developed on RC1-Update1 basis. The solution is a little bit bigger, it has 8 src projects and 4 tests. Most of them are C# projects and there are also a few F# projects. I have one project for the data access with Entity Framework Core.https://kalapos.net/Blog/ShowPost/migrating-from-asp-net-core-rc1-to-rc2-entity-frameworkgergo@kalapos.net (Gergely Kalapos)Mon, 16 May 2016 07:11:00 GMTmigrating-from-asp-net-core-rc1-to-rc2-entity-framework#When05/16/201607:11:00Lately I work a lot with ASP.NET Core and .net core. This is I think the biggest fully open source project Microsoft ever did and between RC1 and RC2 they made huge changes in the execution environment, which successfully confused me in many ways. But all this is fine, since it was only an RC1, and none said that the same stuff will RTM. In this post I summarize the most important settings in project.jsonhttps://kalapos.net/Blog/ShowPost/project-json-settings-in-asp-net-coregergo@kalapos.net (Gergely Kalapos)Sun, 08 May 2016 04:22:00 GMTproject-json-settings-in-asp-net-core#When05/08/201604:22:00This weekend I co-presented a talk about monitoring Azure during the Global Azure Bootcamp in Linz. This post is the written form of my part from the talk.https://kalapos.net/Blog/ShowPost/monitoring-with-application-insightsgergo@kalapos.net (Gergely Kalapos)Sat, 16 Apr 2016 00:39:00 GMTmonitoring-with-application-insights#When04/16/201600:39:00This week I worked on some interesting stuff and fortunately there was a cool learning outcome from it, which is worth a blogpost, so I summarize it here.https://kalapos.net/Blog/ShowPost/how-the-evil-system-xml-serialization-xmlserializer-class-can-bring-a-server-with-32gb-ram-downgergo@kalapos.net (Gergely Kalapos)Sun, 24 Jan 2016 08:45:00 GMThow-the-evil-system-xml-serialization-xmlserializer-class-can-bring-a-server-with-32gb-ram-down#When01/24/201608:45:00On the 14th of January I gave a talk at a local technology meetup in Linz called Technologieplauscherl about the Universal Windows Platform. This post is the written form of the talk, which was intended for people who do not know UWP, but have a strong background in software development (and it's even better if you have some knowledge about C#/XAML based development).https://kalapos.net/Blog/ShowPost/talk-the-universal-windows-platform-one-codebase-for-mobile-desktop-iot-xbox-hololens-etcgergo@kalapos.net (Gergely Kalapos)Thu, 14 Jan 2016 09:20:00 GMTtalk-the-universal-windows-platform-one-codebase-for-mobile-desktop-iot-xbox-hololens-etc#When01/14/201609:20:00Back in 2012 I published a small Windows Store app called PassworWallet, which already had a few thousand downloads over the years and when Windows 10 came out the daily 5-10 downloads went up to 15-20, so I thought it's time to release an update, so the last days I updated it to UWP. This post summarizes the update process.https://kalapos.net/Blog/ShowPost/porting-a-windows-8-app-to-the-universal-windows-platformgergo@kalapos.net (Gergely Kalapos)Thu, 24 Dec 2015 13:18:27 GMTporting-a-windows-8-app-to-the-universal-windows-platform#When12/24/201513:18:27The Universal Windows Platform supports In-App Purchases (IAP). This feature was already available in Windows 8/8.1, but I have not used it before. In this post I explain how you can debug an IAP in a UWP app.https://kalapos.net/Blog/ShowPost/test-in-app-purchases-in-windows-universal-apps-uwpgergo@kalapos.net (Gergely Kalapos)Sun, 29 Nov 2015 18:02:11 GMTtest-in-app-purchases-in-windows-universal-apps-uwp#When11/29/201518:02:11The topic of this post is the beforefieldinit flag. Part I is basically a recap, all those things are already documented and there are great posts about that. Part II is where the fun begins. I googled very long, but I did not find that information on the web (that's why I write this now).https://kalapos.net/Blog/ShowPost/fields-in-types-marked-with-beforefieldinit-are-initialized-earlier-when-the-image-assembly-is-ngenedgergo@kalapos.net (Gergely Kalapos)Sat, 14 Nov 2015 23:00:00 GMTfields-in-types-marked-with-beforefieldinit-are-initialized-earlier-when-the-image-assembly-is-ngened#When11/14/201523:00:00This post shows how to implement periodic tile updates in web api with the NotificationsExtensions.Win10 NuGet package for UWP Apps.https://kalapos.net/Blog/ShowPost/periodic-tile-updates-with-web-api-on-uwpgergo@kalapos.net (Gergely Kalapos)Tue, 29 Sep 2015 05:26:00 GMTperiodic-tile-updates-with-web-api-on-uwp#When09/29/201505:26:00Last week I was in San Francisco at the Build conference and in the “Introducing ASP.NET 5 Session” there was a short demo, which was very interesting: Scott&Scott basically created an asp.net project and opened it in Visual Studio Code and compiled and started the whole thing on a Mac.https://kalapos.net/Blog/ShowPost/building-asp-net-applications-under-macgergo@kalapos.net (Gergely Kalapos)Wed, 06 May 2015 05:49:37 GMTbuilding-asp-net-applications-under-mac#When05/06/201505:49:37Recently I became very excited about functional programming and this post summarizes the first step of this journey. During my master’s studies in Linz I had two courses dealing with functional programming: Once I learned Hashkell, but it was only a part of a general programming languages course and I also toke an “Object-functional Programming” course and learned a little bit of Scala. Now I decided to learn OCaml… https://kalapos.net/Blog/ShowPost/functional-programming-i--ocamlgergo@kalapos.net (Gergely Kalapos)Tue, 07 Apr 2015 11:37:22 GMTfunctional-programming-i-–-ocaml#When04/07/201511:37:22I wrote my master's thesis about database synchronization and I also implemented a framework for mobile apps which synchronizes SQLite with MS SQL Server as a part of it. Maybe there is someone out there who is interested in this topic, so I decided to share the thesis with the public.https://kalapos.net/Blog/ShowPost/database-synchronization-between-mobile-devices-and-classical-relational-database-management-systems--masters-thesisgergo@kalapos.net (Gergely Kalapos)Wed, 25 Mar 2015 07:38:21 GMTdatabase-synchronization-between-mobile-devices-and-classical-relational-database-management-systems-–-master’s-thesis#When03/25/201507:38:21Since I have to look up these things at least twice a year I decided to write an extremely compressed summary about the GC types/settings in the .NET framework.https://kalapos.net/Blog/ShowPost/gc-flavors-in-netgergo@kalapos.net (Gergely Kalapos)Sat, 17 Jan 2015 03:04:00 GMTgc-flavors-in-net#When01/17/201503:04:00I wanted to check out my Git repository which is hosted on Visual Studio Online with Xcode on my Mac and I experienced some strange behaviour. This post is about the bug and its solution.https://kalapos.net/Blog/ShowPost/using-git-as-scm-in-visual-studio-online-with-xcode-6-1gergo@kalapos.net (Gergely Kalapos)Tue, 16 Dec 2014 14:56:55 GMTusing-git-as-scm-in-visual-studio-online-with-xcode-6-1#When12/16/201414:56:55This post shows how to pass data from C# code to a portable, pure C++ layer via the Windows Runtime. This can be interesting to people who write portable C++ libraries, especially for mobile platforms.https://kalapos.net/Blog/ShowPost/passing-data-from-c-to-pure-c-via-windows-runtimegergo@kalapos.net (Gergely Kalapos)Mon, 08 Dec 2014 12:27:26 GMTpassing-data-from-c-to-pure-c-via-windows-runtime#When12/08/201412:27:26Two posts from me were published on the about:performance blog about the async capabilities of C#https://kalapos.net/Blog/ShowPost/asynchronous-programming-in-cgergo@kalapos.net (Gergely Kalapos)Sun, 09 Nov 2014 12:59:38 GMTasynchronous-programming-in-c#When11/09/201412:59:38This is a short post on the new range based for loop in C++11 and a short summary about an ~1h debugging session and its conclusion.https://kalapos.net/Blog/ShowPost/range-based-for-loop-in-c-11-and-the---signgergo@kalapos.net (Gergely Kalapos)Wed, 10 Sep 2014 07:32:00 GMTrange-based-for-loop-in-c-11-and-the-‘-’-sign#When09/10/201407:32:00This week I was working on some stuff where I calculated some values in C# and I wanted to send it to a native C++ layer to use the values there. The data was originally stored in a Dictionary<int List<long>>. As soon as I realised that I want to work with this in C++ it was clear that the Dictinary and the List classes are not the best, so instead of the C# collections I used a C# jagged array and I hoped that the framework can marshal it automatically. Well I was naive…https://kalapos.net/Blog/ShowPost/marshalling-jagged-arrays-from-clr-to-nativegergo@kalapos.net (Gergely Kalapos)Sat, 02 Aug 2014 08:02:00 GMTmarshalling-jagged-arrays-from-clr-to-native#When08/02/201408:02:00his semester I was a part of a small project with Oracle labs. The goal was to see if the JavaScript engine of MongoDB could be replaced by a JVM based JavaScript engine and if so then building a prototype to show how this can be done. This post is a documentation/wrap up for that project.https://kalapos.net/Blog/ShowPost/changing-the-javascript-engine-of-mongodbgergo@kalapos.net (Gergely Kalapos)Sun, 13 Jul 2014 20:48:12 GMTchanging-the-javascript-engine-of-mongodb#When07/13/201420:48:12When I work on Windows 8 Apps I often have the situation where I have a class which has a longer initialization process (e.g. deserialising some state from the file system, loading data over the network, make some complicated calculation, etc). One solution would be to write a public 'initialize' method and call it first to initialize the class. The problem with this is that it is…https://kalapos.net/Blog/ShowPost/classes-with-long-initialization-process-implemented-with-tasks-in-cgergo@kalapos.net (Gergely Kalapos)Wed, 09 Jul 2014 17:36:35 GMTclasses-with-long-initialization-process-implemented-with-tasks-in-c#When07/09/201417:36:35