Vacature Internship Model-Checking Online Payment Services (Period Continuous)

Internship Model-Checking Online Payment Services (Period Continuous) - WO / University

About the assignment

In recent years, DISH's ecosystem has shifted from a traditional POS solution to a modern omnichannel-based solution. With respect to payments, the traditional approach was quite straightforward. For instance, one would order a drink and then pay the amount required for that order, either by card or cash. This linear sequence of events is quite easy to oversee. Hence, verifying the correctness of these events has also not been a serious concern. In our modern approach multiple cloud-based systems play a role, in order to establish a successful iDEAL or PayPal payment for instance. Among these systems we have back-ends that determine the amount to be paid, services that initiate the payment, services that complete the payment and your mobile device that acts as a front-end. Verifying the correctness of these interacting systems is a serious challenge. The fact that communication between these systems mostly happens asynchronously, and across multiple vendors, makes verification even harder.

We would like to see a model-checking based solution that verifies the correctness of these interacting systems. Based on some formalized requirements, one can design and refine formal models of these systems.  Designing these models can be done using some formal modelling language. Refining is done through traces extracted from these models by a model checker that also considers the requirements. These traces can be made executable and be run against booq's online payment services through REST APIs. Depending on the output of the running system one can improve the formalization, or show that the implementation needs improvement. This technique is also known as Counter Example Guided Abstraction Refinement (CEGAR). As the behavior of the individual systems is typically well understood; their complex interactions usually to a lesser degree, leading to unforeseen corner cases. These corner cases may for instance present themselves in practise as users not being able to complete a payment successfully.  By applying the CEGAR-based solution we hope to catch these corner cases early and thus improve the correctness of the DISH platform in general.

What do we offer?

• Daily nutritious lunches, on us

We believe that having lunch together is important. Bread, saltines, fruit, juice... It's ready for you to enjoy, and it's complementary. Have a fun chat with your colleagues or enjoy a game of table football. A real luxury that you don't have to prepare your lunch every morning.

• Friday afternoon; drinks and snacks

At Eijsink, no Friday afternoon passes over without a drink. Regardless of if you're located in Oosterwolde or Wateringen. With a soda, beer or wine we toast to the weekend. And let's not forget the snacks! If you don't feel like having a drink, no problem, it's not obligatory.

• Learning & development; a place for you to grow

A challenge and a varied job within a modern organization? Then we are a match! Apart from outstanding primary and secondary employment conditions we offer the opportunity for you to follow intern trainings and to grow into a new role. This way you can develop, and we grow alongside with you.

We are Eijsink

The cash register supplier? A nickname that we carry with pride! Currently we have grown into a full-fledged software company in the Dutch hospitality industry! For over four decades we help hospitality entrepreneurs to work smarter with ironclad solutions. With more than 200 colleagues who proudly represent Eijsink day-in and day-out. With our in-house developed DISH-software, we offer a unique total platform.

Within 40 years Eijsink has grown to be a software company with knowledge of people. With colleagues located at our head office in Hengelo, IT-colleagues in Enschede and Oosterwolde, or at our locations in Breda, Den Haag en Amsterdam. Experience our expertise and tools at our leading clients such as De Efteling, Ahoy Rotterdam or De Beren.

We would like to meet you

If you are a student WO Computer Science and you are interested in this assignment, you can apply directly! Let's drink a coffee and talk about the possibilities. We hope to see you soon!