Optics11 is a fast-growing high-tech company based in Amsterdam, developing advanced fiber optic sensing systems for the most demanding environments. Our technology detects the earliest signs of failure in critical assets – from high-voltage energy infrastructure to subsea and defense applications – and gives our customers precise, real-time data they can act on. Within our Underwater Security business we develop sensing technologies that help detect and monitor underwater threats. Our solutions include OptiBarrier, designed for immediate, over-the-horizon threat detection, and OptiArray, our low-power optical thin-line towed array for unmanned underwater vehicles and submarines. The Role As a Senior Embedded Software Test Engineer at Optics11, you own the embedded software system-test capability for our sensing interrogator platforms. You define, automate, execute, and continuously improve Hardware-in-the-Loop (HIL) and box-level integration and regression testing so that software and firmware release candidates are qualified on representative hardware before they move downstream to formal verification, FAT (Factory Acceptance Test), field, or application validation. Your scope covers the integrated behavior of embedded Linux applications and services, internal and external APIs, hardware interfaces, firmware and FPGA interactions, system control, calibration and configuration, diagnostics, data acquisition, boot and update behavior, recovery mechanisms, and sensor interfaces. You build and maintain automated test frameworks, HIL benches, test harnesses, CI/CD integration, and objective release evidence that make product behavior repeatable, observable, and measurable. You are part of the Sensing Platform Team and work closely with Embedded Software, FPGA/Firmware, Electronics, Photonics, Architects, Product System Engineering, Product Integration, Verification & Validation, Lifecycle Engineering, application/software teams, and external development partners. The primary ownership of this role is integrated interrogator/HIL system-level testing and release qualification. It complements developer-owned unit and component testing and does not replace independent formal verification, compliance, environmental, or end-to-end application validation performed downstream. Responsibilities • HIL & System-Level Test Development • Own the interrogator/HIL test strategy, system-level regression suite, and embedded software/firmware release qualification approach for the Sensing Platform. • Translate product, software, firmware, and interface requirements into test plans, acceptance criteria, coverage objectives, and automated regression tests. • Design, build, and maintain HIL test setups using representative hardware, simulated or real sensor inputs, and remotely controlled lab equipment. • Develop maintainable Python-based test automation for device control, test orchestration, data capture, analysis, and reporting. • Integrate hardware-based regression testing into CI/CD pipelines, enabling repeatable and largely automated testing of release candidates. • Maintain traceability between requirements, test cases, defects, results, and release evidence. • Release Qualification & Failure Analysis • Qualify embedded software and firmware releases on representative interrogator hardware before downstream V&V, FAT, field, or application validation. • Design and execute system, negative, stress, endurance, fault-injection, restart/recovery, upgrade/rollback, and robustness testing based on product risk. • Analyze logs, system state, performance, timing, communication behavior, and data outputs to identify regressions and integration issues. • Triage failures and support root-cause analysis across software, firmware, FPGA, electronics, photonics, sensors, and system interfaces. • Reproduce field, production, and customer issues in laboratory/HIL environments and turn important failures into permanent regression coverage. • Provide clear, evidence-based input on release readiness, known limitations, unresolved defects, and coverage gaps. • Test Engineering & Technical Ownership • Identify quality risks, missing coverage, weak observability, testability limitations, and failure scenarios, and drive practical improvements. • Evaluate test frameworks, HIL architectures, simulation approaches, instrumentation, and automation solutions. • Work with Software, Firmware/FPGA, Electronics, Photonics, Systems, Integration and V&V engineers to improve design-for-testability, interfaces, diagnostics, and acceptance criteria. • Own significant HIL, system-test, and automation workstreams with minimal guidance, while keeping test environments, tooling, configurations, and documentation reliable and reproducible. • Contribute to requirement, design, code, test-plan, and test-result reviews. • Collaboration & Continuous Improvement • Collaborate across multidisciplinary engineering teams to solve complex integration and product-quality issues. • Communicate test results, quality risks, defects, dependencies, and release readiness clearly to technical stakeholders. • Share knowledge and mentor peers in embedded software testing, HIL automation, failure analysis, and robust test design. • Continuously improve automated coverage, CI/CD quality gates, test reporting, diagnostics, test-environment stability, and release processes. • Reduce flaky, manual, and repetitive testing through reusable test assets and reliable automation. What we offer • Join one of Europe’s fastest-growing deep-tech scale-ups. • Real impact: your work directly shapes our growth and success. • A great team in an international organization with colleagues from more than twenty nationalities. • A competitive salary and benefits package. • 30 days of holiday per year. • Fresh team lunches five times a week, plus regular team activities and company events. Requirements • BSc or MSc in Computer Science, Software Engineering, Electrical Engineering, Embedded Systems, or related technical discipline. • 5+ years of relevant experience in embedded software testing, embedded systems integration, test automation, HIL testing, software quality engineering, or related fields. • Strong experience testing embedded products on physical hardware and integrated systems throughout the product-development lifecycle. • Strong Python skills for test automation, tooling, laboratory equipment control, and analysis. • Strong understanding of embedded Linux systems, Linux applications and services, software processes, networking, logging/diagnostics, and hardware/software interaction. • Hands-on experience designing or maintaining automated test harnesses, HIL or system-level test environments, and regression suites for embedded products. • Experience with automated test frameworks such as Pytest, Robot Framework, or comparable tools; Git; Linux; Docker; and CI/CD systems such as GitLab CI, Jenkins, GitHub Actions, or similar. • Experience testing software APIs, hardware interfaces, inter-process communication, system-control functionality, data acquisition, and integrated embedded-system behavior. • Strong analytical skills and experience applying structured test design, defect triage, problem-solving, and root-cause analysis methods. • Experience debugging complex issues across software, firmware, FPGA, electronics, and hardware boundaries using logs, traces, diagnostics, and laboratory equipment. • Strong communication skills in English and the ability to explain technical findings and product-quality risks clearly to both technical and non-technical stakeholders. • Eligible for required EU/NATO/security screening or clearance, where applicable to the role. Nice to have • Experience in multidisciplinary high-tech product development involving software, firmware, electronics, FPGA, photonics, sensing, manufacturing, or defense/security applications. • Experience with laboratory automation and instrumentation, for example programmable power supplies, function generators, switching/multiplexing equipment, serial interfaces, oscilloscopes, logic analyzers, or LabVIEW-based setups. • Experience with SIL, simulation, device emulation, or virtualized test environments that complement physical HIL testing. • ISTQB, or comparable test certification, is a plus, but hands-on embedded test-engineering experience is more important. • Experience designing fault-injection, endurance, recovery, power-cycle, upgrade/rollback, and robustness tests for embedded systems. • Familiarity with systems engineering, product verification, requirement traceability, configuration management, and product lifecycle management processes. Screening You will work with clients in the defense and security sectors. Obtaining a Certificate of No Objection issued by the AIVD, the Dutch General Intelligence and Security Service, is mandatory. This means you will need to undergo a security screening. We will explain the process and guide you through the applicable requirements.