The Services I offer


Because of my business administration background combined with my knowledge of ICT I’m skilled in establishing ICT strategies, business requirements and coordinating the execution of these activities.


As certified .NET/SharePoint developer and experience expert at large and complex projects I provide the expertise, as team lead as well as developer, necessary to successfully deliver development projects.


Unclear expectancies, speed of problem solving and lack of transparency are well-known problems of application management. I can take over the application management and offer clear agreements and one contact.

Hello, I am Dennis Tjassens...

I'm a SharePoint & .NET consultant living in Den Haag, The Netherlands. I have worked with companies like De Tweede Kamer, KPN, ASM, Miele and Philips, and currently working as a SharePoint developer at De Vrije Universiteit Amsterdam. SharePoint consulting is not just a job for me, it's a passion.

View my Works





Web Development


Mobile Development


SharePoint Development

The most recent works

Vrije Universiteit Amsterdam (Freelance)

The project exists of a platform for students and employees. All administrative issues which both groupds are confronted with can be handled through the use of the platform. For students there are for instance means to check their schedule and grades, register for new courses and evaluate taken courses. Employees are given the ability to request holidays, check salary slips and put in request for materials.

My role in the whole was part consulting and part developing. For all subprojects executes it started with discussing and collecting requirements. After this the technical design was created based on the requirements. Based on this design the functionality was build. The technologies used for the projects are: SharePoint 2010, ADFS, HTML, CSS, XML, XSLT, WCF, Web services, Unity, Entity Framework, C#, javascript, JQuery and ASP.NET.

Tweede kamer (commissioned by InterAccess)


The project exists of a platform for the storage and the editing of the plenary meetings. All meetings of the “Tweede Kamer” have to be documented. The project and the application called “VLOS” arrange all the administrative processes as well as documenting the actual content of the meetings. The application is a part of a whole chain of application that means that they need information as input and they also deliver an end product to other applications.

My role in the project was part consulting and part developing. For almost all the subprojects the primary processes needed to be viewed and based upon this review functionality needed to be developed. My role was that of a team lead for the SharePoint parts and solution architect. Build upon the functionality I would set up the solutions for the application for SharePoint and .NET related components. I guided the other SharePoint and .NET developers and helped them where needed. The technologies used for the project are: SharePoint 2010, ASP.NET Mvc4, Entitiy framework, HTML, CSS, XML, XSLT, WCF, Web services, C#, WPF, Javascript and JQuery.

KPN Wholesale (Freelance)

The project exists of a platform that offers self-service functionality to the business clients of KPN. One of these functionalities was the request of server space and broadcast towers. This used to be managed in a non-digital way only. For this platform a component is developed where this can be done digitally based on previously filled requests. It was also possible to view the status of these requests and edit these requests further.

My role was that of a solution architect and developer. Based on the requested functionality a technology stack was chosen. Based on this stack I developed an architecture that fits in the best with the existing architecture of the platform. The technologies used for this project are: Umbraco, Entity Framework, WebformMVP Framework, C#, ASP.NET, Javascript and Jquery.

Deloitte (Freelance)

Fast Ventures

The project was creating a platform for new ventures. The platform is a website with information and the possibility to contact Deloitte regarding this subject. The website needed to be adjustable by the customer therefore CMS functionality needed to be provided.

My role was rebuilding an existing ASP.NET Webforms application. This application needed to be linked with a SharePoint 2010 environment. In this SharePoint environment the CMS functionality is build with which the client can manage the website themselves and fill the content. The technologies that are used for the project are: SharePoint 2010, ASP.NET, C#, javascript and jQuery.

Sportcity (Freelance)

iPad aanmeldings App

The project was about automating the registering process for all new members in the fitness clubs. This process used to be done in a non-digital way. This meant that after filling all the forms with the customer it had to be done again to get the details into the back-end system. To improve this process Sportcity decided that there needed to be developed an iPad app to digitalize this process.

My role was that of a solution architect and a developer. Based on the requests of Sportcity a solution needed to be created with the proper technologies. The most important aspects of the app existed of retrieving data from the back-end systems, saving all the registering customers in a database and creating a specific user interface which was not only intuitive but also appealing. The technologies used for this project are: Sencha Touch, ASP.NET MVC, Entity Framework, C#, javascript, Autofac DI and JQuery.

Philips (commissioned by Capgemini)


The project existed of creating dashboards that show all the projects run within Philips based on the costs, ROI and planning. These dashboards are made to provide management with more insight into the status of all the projects run Philips wide.

My role was to determine a solution together with the business owners and construct a solution accordingly. When the solution was created I lead the development where I worked together with two other developers to create the required functionality. The technologies used for the project are: SharePoint 2007, C#, ASP.NET, XML, XSLT, javascript and jQuery.

Vitens (commissioned by Capgemini)

The project exists of a selfservice internet platform for customers. On this platform customer request information about the water quality in the region, read news about the water supply, register when moving and alert Vitens when confronted with a malfunction.

My role was that of developer. The design needed to be developed in SharePoint and was required to support IE6+, firefox, chrome and safari. Besides the design the functionality needed to be developed. The technologies used for this project are: SharePoint 2007, SharePoint 2010, C# and ASP.NET.

Vendere (Freelance)

Intra & extranet

The project initially started with solving critical problems with the SharePoint 2007 environment. After solving these issues the request arose to evaluate the SharePoint environment. After this evaluation the necessity became clear to automate the existing workflow solutions.

My role was evaluating the current state of the environment. After this evaluation my role became developing new functionality to solve the issues they faced with the current workflow solution. The technologies used for the project are: SharePoint 2007 and C#.

Your ICT (Freelance)

SharePoint Consultancy


YourICT has required my services multiple times over the years. YourICT is an ICT service provider that is confronted with existing SharePoint environments from time to time. Because they do not have extensive SharePoint knowledge in-house they call on me to consult and offer support when working on client platforms where they encounter problems.

My role is consulting and problem solving. My tasks exist of installing SharePoint, solving problems with existing environments and optimizing existing environments.

Miele (commissioned by Capgemini)

Responsible for developing functionality in the public facing and self-service website of Miele. The website contained functionality like registering for workshops, registering products, a web shop and many more.

The functionality was build using CSS, HTML, C#, Linq, WCF, XML and XSLT. Especially the registering of products and actions was a complex process wich was done by communication with SAP, Lotus Notes and a IBM AS400 platform. For this functionality a custom service layer was build to link all these platforms.

Coa (commissioned by Capgemini)

Responsible for building functionality of a refugee platform within the Netherlands. This platform was build to connect refugees and city officials in order to find suitable housing area's for these refugees. The platform is build in custom .NET and build using the MVP pattern.

The functionality was build using CSS, HTML, C#, Linq2SQL and WCF. The data for the application was gathered from other applications through WCF services and enriched with data entered in the platform.

ASM (commissioned by Portiva)

Responsible for coordinating and leading the development of a public facing website in a SharePoint 2013 environment using ASP.NET, WCF, HTML 5, CSS 3, C#, Linq and CAML. For this website numerous components were developed like web templates, Webparts, a custom masterpage (based on HTML5 and CSS 3), timer jobs, features, managed navigation (based on termstore) and other components. The development is based on the MVP pattern. For the deployment through the DTAP Powershell scripting was used. The website is released sucessfully.

Keep in Touch with me

A new project lining up, busy with developing a new product or technology related questions? Please feel free to contact me through the contact form for an initial, free, consult

Dennis Tjassens
Boekelermeerstraat 9
2493 XJ Den Haag