Domain-specific languages (DSLs) often divide engineering teams. When they work, they make complex systems easier to reason about. When they fail, they become costly internal tools that no one maintains. The real challenge is not how to build a DSL, but when building one is justified.
That question will sit at the centre of “Designing Quantum Computing DSLs with Eclipse Xtext”, a session at OCX by Matteo Di Pirro (senior software engineer) and Nicola La Gloria (co-founder and CTO) at Kynetics and contributors to Eclipse Hara.
Today, most quantum programming tools are exposed as APIs for general-purpose languages such as Java or Python. While this lowers the entry barrier, it also forces developers to model quantum concepts through host-language abstractions. As Matteo explains in an interview, “the syntax that we have is complex. Writing quantum algorithms is still something that we need to learn how to do properly.”
He also mentions that quantum programming today is still closer to low-level work: “quantum code feels like assembly code, in the very beginning of computer programming.” Wrapping that complexity in a library does not automatically make it easier to understand.
A language-first approach using Eclipse Xtext offers a different path. Instead of exposing every technical detail, a DSL can focus directly on domain concepts such as qubits, initialisation, and interaction. The goal is intentional simplification: removing syntax that distracts from the problem being solved. In this sense, a DSL is not about adding expressive power, but about reducing cognitive overhead when working in a complex domain.
Importantly, Matteo is explicit about the limits of this approach. We can imagine semantic validation as a type system in a classical programming language: both can rule out certain classes of errors early, but neither can guarantee correctness in all cases. As he explains, “there are classes of errors that we cannot catch early on using a DSL, using semantic validation. Similarly, there are some errors that we cannot catch using type systems. These classes of errors won’t be caught statically”
Quantum software further complicates this picture by introducing entirely new classes of failure that depend on runtime conditions or the characteristics of the target hardware. Acknowledging those limits, rather than hiding them, is part of designing trustworthy languages.
Beyond tooling, this OCX session will address why many DSLs fail in practice. Technical quality alone is not enough. Without an active community using and evolving the language, even well-designed DSLs stagnate. Requirements must come first, and languages should start small, evolving only as the domain becomes better understood.
At OCX, Matteo and Nicola will also deliver a second joint session, “Navigate the Complexity of Deploying AI at the Edge on Embedded Systems”, exploring similar modelling challenges in embedded and edge environments.
Attendees will leave with a clearer framework for deciding when a DSL is worth building, when an API is enough, and where language design genuinely reduces complexity. Through concrete examples from quantum computing and beyond, the session focuses on trade-offs, limits, and evolution.
If you are designing tools for complex domains or questioning whether a DSL is worth the cost, this session is best experienced live. Join Matteo Di Pirro and Nicola La Gloria in Brussels at the Open Community Experience 2026 to explore these decisions in depth and see how language engineering applies in real-world systems.
