Experienced Software Engineer Java/.NET Platform

Comsol AB · Stockholm · Tills vidare · Deadline 2026-12-31

Comsol AB is seeking an **Experienced Software Engineer Java/.NET Platform** based at its office in central Stockholm. The role focuses on developing the runtimes, libraries, build systems, and platform integrations underlying the cross-platform engineering software COMSOL Multiphysics®. Responsibilities involve working predominantly in Java and C# across Windows, Linux, and macOS to evaluate runtime updates, investigate compatibility issues, implement or backport APIs, and develop automation for recurring platform and dependency tasks. Engineers also write and review code, contribute to technical specifications, and design or evolve build and developer infrastructure. The position requires **onsite presence during onboarding**, after which hybrid working options become available. Applicants must hold an **M.Sc. or equivalent degree** in computer science, engineering, mathematics, or physics, alongside several years of professional software development experience and proficiency in at least one object-oriented programming language. Candidates need an interest in complex systems; no background in physics or simulation is required. Experience with large, mature codebases, Java or .NET runtime ecosystems, build systems, cross-platform development, and developer infrastructure is highly valued. Applications may be submitted in English or Swedish and must include a university diploma with grades.

We are looking for an experienced software engineer to join the team responsible for developing the software platforms underlying COMSOL Multiphysics®. You will work with the runtimes, libraries, build systems, and platform integrations that form the foundation of a large, cross-platform engineering software product. The majority of the development is done in Java and C#, together with build and automation tooling.

About COMSOL

COMSOL develops cutting-edge mathematical modeling software that powers innovations in physics and engineering. Our flagship product, COMSOL Multiphysics®, is widely used across all fields of engineering, manufacturing, and scientific research to model multiphysics systems. Our customers leverage our software to understand, predict, and optimize product designs and processes. Founded in Sweden in 1986, COMSOL has expanded globally with 16 offices employing more than 500 people worldwide.

Role

Based in our newly renovated office in central Stockholm, you will join the core group developing the user interface, communication, and data layer functionality of the COMSOL product suite. The group is also responsible for the Application Builder, Model Manager, COMSOL Server, and COMSOL Compiler functionality, which customers use to create, manage, deploy, and run simulation models and apps.

In this role, you will work on several of the software platforms on which our products are built. This includes the Java and .NET runtimes and their ecosystems, third-party libraries, database connectivity and persistence technologies, application launchers, build systems, and integration of vendored software. The work spans multiple operating systems and a large codebase with a long development history.

You will evaluate and integrate new runtime and library versions, investigate compatibility issues, implement or backport APIs and other changes where needed, and develop automation that makes recurring platform and dependency work more efficient and reliable.

The role also provides opportunities to evolve the platforms themselves. Depending on your experience and interests, this can include introducing new platform capabilities and APIs, improving how runtimes and third-party components are integrated, evolving build and development infrastructure, and finding better ways to support development across the product organization. You will have room to identify improvements and contribute to the longer-term technical direction of the areas you work with.

Responsibilities include writing and reviewing code, investigating platform and compatibility issues, contributing to technical specifications and design, developing build and platform infrastructure, and testing changes across the supported product platforms.

Qualifications

For this position, we are looking for an experienced software engineer with the following qualifications:

Experience with the following will be highly valued:

No background in physics or simulation is required. At COMSOL, you will be part of a company where software developers, mathematicians, physicists, and engineers work together to develop software for science and engineering.

Working at COMSOL

At COMSOL, platform engineering is closely connected to product development. You will work on technical foundations used throughout the COMSOL product suite, with opportunities both to ensure that those foundations remain robust and current and to improve how they support future product development. Decisions about runtimes, libraries, build systems, and operating-system support have a direct impact on a complex engineering product with a long lifetime.

New team members quickly become essential contributors to ongoing development projects. As the company continues to expand, there are plenty of opportunities for employees to advance in their roles and become leading experts in their areas of focus. This journey will be accompanied by experienced colleagues and a collaborative working environment.

We also offer:

To ensure a smooth onboarding process, onsite presence is required. Once onboarded, hybrid work options are available.

To Apply

Does this sound interesting? Submit your application in English or Swedish using the form below. Make sure to include:

Please include your university diploma with grades, regardless of when the degree was obtained. Kindly note that applications submitted through other channels will not be considered.

To recruiters, please note that the target channels for this position have already been selected.

For more information, contact Mikael Sterner at tel. 08-412 95 00.

We review applications continuously.

Apply now

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