Senior Rust Developer - Qt / C++ / FFI w Warszawa, Polska

Senior Rust Developer – Qt / C++ / FFI

Miejsce pracy: Warszawa

Technologies we use

Expected

• Rust
• C++
• Git
• Linux
• Windows Server
• MacOS
• Docker
• GitHub
• GitLab

Optional

• Figma

Operating system

• Windows
• macOS
• Linux

About the project

Long-term project focused on developing production-grade solutions combining Rust, C++ and Qt 6.

Main focus on developing high-quality Rust code, with emphasis on object models, memory safety, type systems, procedural macros, and safe APIs across the Rust/C++ boundary.

Team works with a public backlog, tasks assigned issue by issue and re-planned on a sprint basis.

Opportunity to work on challenging systems-level problems in a review-driven engineering environment.

Initial priorities include object model and memory-safety work, type-system development, procedural macros, Rust/C++ FFI, public API design and stabilisation.

Your responsibilities

• Develop production-quality Rust code and, where required, C++ code.
• Design and maintain idiomatic, safe Rust APIs.
• Build safe Rust wrappers around existing C++ functionality.
• Work with Rust ↔ C++ FFI, ideally using cxx.
• Develop and maintain procedural macros using syn, quote and proc-macro2.
• Provide high-quality compile-time diagnostics for procedural macros.
• Work with ownership, lifetimes and object lifetime management across the Rust/C++ boundary.
• Design and stabilise public library APIs, taking into account semver, deprecations and breaking changes.
• Maintain cross-platform Rust builds across Linux, Windows/MSVC and macOS.
• Write tests alongside every change.
• Maintain documentation and rustdoc for public APIs.
• Participate in code reviews using Gerrit.
• Follow a small-commit, review-heavy development workflow.
• Contribute to security reviews and threat modelling for a systems-level library.
• Analyse memory-safety and trust-boundary risks across the Rust/C++ FFI surface.
• Collaborate with the team responsible for the Qt/C++ layer.

Our requirements

• Senior-level professional experience with Rust, including strong knowledge of ownership and borrowing, Rc, RefCell, Weak, unsafe and Rust aliasing rules, Pin, lifetime-parameterised APIs.
• Hands-on experience with Rust/C++ FFI, preferably using cxx.
• Experience designing safe Rust abstractions and wrappers over C++ code, including object lifetime management.
• Practical experience with procedural macros, including syn, quote and proc-macro2.
• Experience designing and maintaining public Rust library APIs.
• Strong understanding of semver, breaking-change management and deprecation strategies.
• Experience with cross-platform Rust build engineering, including https://jobeax.com/link/W6WXcJrr7KQAzcRB, linking against native libraries, Linux, Windows/MSVC, macOS.
• Strong engineering and quality discipline: tests with every change, cargo fmt clean, no new Clippy warnings, documented safety rationale for any new unsafe code, rustdoc for all public APIs.
• Experience with threat modelling and security reviews for systems-level software.
• Ability to reason about memory safety and trust boundaries across Rust/C++ FFI.
• Working knowledge of Qt 6, including QObject, properties, signals/slots, QVariant, QMetaType, QML object ownership.
• C++17 knowledge sufficient to read and modify the bridge layer.
• Comfortable working with Gerrit, small commits and review-heavy development processes.
• Professional written and spoken English.

Optional

• Previous contributions to Qt, CXX-Qt, qmetaobject-rs or similar binding projects.
• QML / Qt Quick application development experience.
• Experience publishing and maintaining crates on crates.io.
• Knowledge of rcc and Qt resource handling.
• Experience with QML debug/preview protocols.
• Experience with async Rust / Tokio integrated with a native event loop.
• Existing Qt Account and signed Qt Contributor Licence Agreement.

Benefits

• sharing the costs of sports activities
• private medical care

SQUARE ONE RESOURCES sp. z o.o.

At Square One Poland we link IT experts with the business. With over 25 years of experience, we specialize in recruitment processes on a global scale. Despite years of experience, we still have a startup DNA and this is our advantage. Our offices are located in London and Warsaw, however, we can reach clients from all over the world, from start-ups to big worldwide corporations.