The Model as Code Paradigm: An Interview with Juozas Vaicenavicius of Sensmetry
SysIDE (pronounced "Seaside") has quickly stirred interest in the SysML v2 community. The primary paradigm is to treat systems model as code. SysIDE consequently is a text-first modeling environment that is delivered in the form of an extension to VS Code.
I talked to Juozas Vaicenavicius, CEO of Sensmetry, on August 28, 2025.
Tool vendor out of necessity
Sensmetry did not start as a tool vendor, but as a provider of engineering services in the space of autonomous driving. The team wanted tools that could handle sensor data, digital twins, and domain-specific languages. Modeling tools seemed to do just that. Therefore, Sensmetry was acquiring "the usual suspects", Cameo, Ansys etc.. And they were amazed on how difficult it was to work with these tools. They were not scriptable, hard to integrate, and unsuitable for CI/CD workflows. That pain led to the creation of SysIDE.
The main competition is people hacking away with YAML files or creating their own DSLs.
Juozas Vaicenavicius, CEO of Sensmetry
Since its founding in 2019, the excitement of autonomous driving has passed its peak and Sensmetry has reduced engineering services and prioritizing towards tool development.
Today, Sensmetry has over 10,000 active users and a growing number of customers from aerospace (DLR), automotive and many others.
Model as Code
The core idea of Sensmetry is Model as Code. This follows the examples of Infrastructure as Code. The idea is that artifacts should always be both, human readable and machine readable. This ensures rigor and reproducibility. The irony is that all SysML models (both, v1 and v2) are machine readable in principle, but not in practice.
For Juozas, The benefits of SysML v2 reach further: SysML v1 lacked the rigor that SysML v2 provides. By shifting to a code mindset, models become unambiguous and analyzable.
While SysIDE focuses on the text notation, Juozas sees value in the SysML v2 API as well. When interacting with a source of truth, it does not matter whether it is via code or via the API. There is room for both.
Sysand is an open source package manager for SysML v2 libraries, enabling engineers to find, reuse, and share model libraries. (Currently in development as "Librarian", available in Q3 2025)
Sysand Announcement (as "Librarian")
The focus on model as code positions SysIDE uniquely. Following a path that worked for software development, they are developing Sysand (formally SysIDE Librarian), a package manager for SysML v2, enabling reuse and collaboration.
Openness is the future of product development
When we discussed the various integration avenues, Juozas is pragmatic about interoperability. The need to connect artifacts, from requirements to system elements to design, all the way to PLM, is gigantic. OSLC, for instance, has its place. What we need are feasible options and accepted standards.
Following the model as code line of reasoning, he pointed out the importance of allowing developers to work with the model. SysIDE makes it easy to work with the model in Python.
Libraries and applications will be built on top [of SysIDE], and that's where SysML v2 will really take off. Python can be the glue language for any type of architecture, modeling for different types of use cases, because other things can be embedded into it.
Juozas Vaicenavičius, CEO of Sensmetry
Open source plays a central role in this vision. Sysand, in particular, could form the backbone of a broader ecosystem, consisting of reusable interface definitions, semantic versioning of ports, and machine-readable contracts.
Conclusion
Juozas Vaicenavicius has a vision of product development that embody a new wave in systems engineering: rigorous, user-friendly and ready for automation. With this, he joins other entrepreneurs, like Sebastian Völkl, Pari Singh or Robert Hämisch. SysIDE challenges the status quo and provides a concrete path toward executable specifications, traceable requirements, and interoperable digital threads.
SysIDE is available for free, so check it out.
