PoC: Subscription Integration- Cooperation between Billwerk+ and doubleSlash

PoC – Proof Of Concept: Subscription Integration Billwerk+ is a state-of-the-art […]

PoC – Proof Of Concept: Subscription Integration

Billwerk+ is a state-of-the-art Subscription Management SaaS platform with a strong and open REST API. It is optimized to reliably and completely automate all recurring business, financial, sales and marketing processes of our customers in the subscription business.

doubleSlash is a proven expert in subscription system integration. Its experts create end-to-end solutions for subscription management so that companies can optimally adapt their products to the needs of their customers. They advise on setting up flexible digital business models and implement them on the system side.

Goal of the Integration PoC

The team itself had set the task of implementing a fictitious freeway vignette service. The primary goal was to realize a corresponding subscription model in order to evaluate the functional and technical coverage provided by Billwerk+’s subscription management and recurring billing solution.

Project requirements for the PoC

A small multi-disciplinary team of experts from Billwerk+ and doubleSlash worked on the PoC in an agile manner and in close coordination within a predefined timebox. The PoC included the following phases:

  • Agile implementation of the PoC
    • Kick-Off
    • Exploration / IT-Design
      • Use Cases
      • technical data model
      • System overview
      • Interfaces
    • PoC Implementation
      • Technical set-up
      • Implementation based on the design artifacts
      • Test
  • PoC Evalutation

PoC – a fictitious vignette service


Transfer your vignettes easily to other vehicles in the fleet within your family.*

Basic fee: 10 EUR / month

Vignette Austria:

27,80 EUR for 2 months

Vignette Switzerland:

35,80 EUR annual

Cancellation at the end of the month


With the Premium tariff, you use the vignette service at attractive prices on a daily basis. The daily vignettes are not transferable.*

Basic fee: 20 EUR / month

Vignette Austria:

1,50 EUR per day

Vignette Switzerland:

1,50 EUR per day

Cancellation possible at any time with pro rata billing of costs.

*You will receive a monthly invoice for both rates. The invoice is always sent on the first day of the following month. Payment is only possible by credit card.

Two different tariffs “Family” and “Flex” should be offered for the vignette service. The Family tariff has a basic fee of 10 euros per month. Once a customer has taken out this subscription, he or she can add the Austrian or Swiss vignette. Prices and duration correspond to the vignettes currently offered on the market. The added value of the subscription model in the Family tariff is that the vignettes are also valid for other vehicles within a family.

The Flex tariff is different, the basic fee is higher, but the tariff also offers greater flexibility, as a valid subscription in the Flex tariff also purchases vignettes on a daily basis.

The implementation of more extensive legal requirements, such as the recipient location principle, was initially deliberately excluded from the PoC.

The implementation by doubleSlash and Billwerk+

In a joint kick-off meeting, we clarified what we understood by subscription management and discussed a definition of the goals in the first place. Since the understanding on both sides was very similar, the PoC use case was quickly formulated in detail. Immediately afterwards, the IT design and the actual implementation were started. A test environment could be provided immediately with the Billwerk+ sandbox. Billwerk+’s API-first approach greatly accelerated the implementation. doubleSlash also found the clear user interface to be a great advantage.

Due to doubleSlash’s existing expertise and deep understanding of subscription system integration, it was easy for them to push forward with a quick implementation. A few more coordination meetings were enough for the doubleSlash integrators to create the PoC.

Billwerk+ Subscription Management Process HUB

The subscription management software and recurring billing solution for your European subscription business. Our open platform complies with European standards according to EU-DSGVO and GoBD and is integrated into the ecosystem of leading third-party providers.

With a strong REST API and ready-to-use integrations with the major payment providers, you are ready to go.APIIntegrations*

*The platforms and software services listed here as integrations are examples that can be integrated into Billwerk+. Please also ask for our standard connectors.

doubleSlash devides subscription management systems into four core components:

PoC: Subscription Integration | Subscription Management components | doubleSlash

*Copyright: doubleSlash: Subscription Management components

If you compare the approaches and prerequisites with which Billwerk+ and doubleSlash work, it quickly becomes clear that there is a very similar mindset, which is the best prerequisite for successful collaboration.

The right mindset for collegial collaboration

Decisive for the success of the PoC was the collective work and the close coordination with the respective technical experts. Thanks to doubleSlash’s deep understanding and many years of experience with subscription integration, it was a very goal-oriented project with a focus on a fast and successful PoC.

We found it particularly positive that doubleSlash knows and considers the entire lead-to-cash process in detail, from shop/marketplace, offer and contract management to incoming payments and revenue recognition. It is particularly important to them to optimally adapt the entire IT landscape to the customer journey, which goes perfectly with options that Billwerk+ offers customers. In addition to the public SaaS environment, a private SaaS or even an on-premise environment can be used as an alternative. This offers a high degree of flexibility for all potential customers.

The open exchange and enthusiasm for the implementation of subscription business models have greatly promoted cooperation at eye level.