Jochen Stärk
is the founder of Mustangproject and Quba, and launched Mustangserver in 2022. He assists with Factur-X/ZUGFeRD standardization and is a member of UN/CEFACT, which is responsible for standardizing cross-industry invoicing. He also continues to work on Mustangserver and Mustangproject, and is responsible for infrastructure.
Martin Wachtveitl
has been helping Mustangserver since 2023 and, in addition to new features, also writes tests and infrastructure automation. In the open source environment, he upgraded EEISI from Java 8 to Java 17 and, building on this, enabled UBL2CII conversion, for example.
Bharti Bhardwaj
has been working for us as an external backend programmer since 2024 and has contributed to the documentation and testing of Mustangproject in the e-invoicing environment, among other things. Not only has she aligned the UBL functionality with that of CII, but she also created the entire Mustangserver homepage, including the validator client WordPress plugin.
Mohammed Bakroon
has almost completely taken over the work on our open source e-invoice viewer Quba from Jochen, released Quba 1.5, and is currently working on Quba 2.0, among other things. He always works his way into new topics very independently and successfully and then implements them visually in a strong way. In this context, he had to build up expertise in a new programming language: we all use Java, but for reasons, Quba 2.0 has to be based on Kotlin and Compose Multiplatform. He is the one of us who is most involved in writing (almost) native applications.
Mert Akemlek
is the person who originally proposed our architecture and is perhaps the most knowledgeable of us all when it comes to API management.
Nils Fornoff
Nils joined us in 2022 and is responsible for design, project organization, and UX. He also designed the facelift for the Mustangserver homepage.
