About this role

JUST ONE, on behalf of its client, a leading software development and systems integration company operating within the defense industry is looking for a Senior Systems Engineer.

This is a hands-on systems engineering role within a product and engineering-driven environment. The successful candidate will own the system architecture end-to-end from early analysis and requirements engineering through design, integration, and validation, working horizontally across product, systems, and verification teams. We are looking for someone who understands mission-critical environments, has worked on complex heterogeneous systems, and knows what it means to be fully responsible for what a system looks like and how it performs in the field.

Responsibilities:

  • Defining end-to-end system architecture including hardware/software integration, interfaces, and operational workflows across multiple subsystems.
  • Eliciting, analyzing, and managing complex stakeholder and operational requirements, aligned where applicable with military standards such as NATO/STANAG.
  • Developing and maintaining system architectures: functional, logical, and physical views using MBSE principles, taking full ownership of what the system looks like throughout the lifecycle.
  • Managing system models and ensuring traceability of requirements, interfaces, and design decisions from concept through to deployment.
  • Leading integration of heterogeneous systems including radars, sensors, communication links, and C2 systems ensuring interoperability and real-time performance.
  • Defining and managing system interfaces and interface control documentation for internal and external system interactions.
  • Defining verification and validation strategies, participating in system-level testing, and ensuring compliance with operational and contractual requirements.
  • Working closely with verification and test teams to ensure everything is properly validated.
  • Applying deep understanding of mission scenarios including air defence operations, situational awareness, and engagement chains to inform system design and integration decisions.
  • Supporting system deployment, acceptance, and in-service lifecycle management.
  • Acting as a bridge between engineering teams, programme management, and end-users, including military personnel where required.
  • Identifying, assessing, and communicating technical risks, trade-offs, and system performance impacts to engineering leadership.
  • Contributing horizontally across departments, analysis, design, integration, verification as project demands require.
  • Mentoring and coaching engineers in systems thinking, MBSE, and the company's engineering methodology.
  • Travelling to customer and project sites as required.
  • BSc or equivalent in Systems Engineering, Electrical/Electronics Engineering, Computer Science, or a related field.
  • 5+ years of hands-on systems engineering experience in defence, aerospace, C2 systems, or similarly complex and demanding technical environments: IT services, enterprise infrastructure backgrounds will not be considered.
  • Experience across at least two lifecycle disciplines: Requirements Engineering, System Architecture & Design, MBSE, System Integration, Verification & Validation Planning.
  • Proven ability to define end-to-end system architectures and manage full lifecycle ownership from design through deployment and in-service support.
  • Familiarity with military standards and operational concepts such as NATO/STANAG, air defence, situational awareness, or engagement chain workflows.
  • Experience integrating heterogeneous systems including radars, sensors, communication links, and C2 platforms.
  • Hands-on experience applying MBSE principles and modelling tools such as SysML.
  • Familiarity with structured data formats (e.g., XML, JSON) for system interface definitions.
  • Understanding of Windows and Linux environments from a system design and deployment perspective.
  • Advanced knowledge of computer networking concepts and architectures.
  • Strong analytical, communication, and interpersonal skills for working in multidisciplinary teams and with military end-users.
  • Willingness to travel to customer and project sites as required.
  • B2B contractors are welcome to apply.
  • Competitive remuneration package
  • Private Medical Insurance package
  • Continuous learning in new technologies
  • Opportunity to work in large-scale projects with talented people

Frequently Asked Questions

Is the salary disclosed for the Senior System Engineer position at Just One | Recruitment & Executive Search Agency?
The salary for this Senior System Engineer role at Just One | Recruitment & Executive Search Agency is not publicly listed. Click "Apply Now" to learn more about the compensation package on their official careers page.
Where is the Senior System Engineer position at Just One | Recruitment & Executive Search Agency located?
This Senior System Engineer role at Just One | Recruitment & Executive Search Agency is based in Athens, Attica, Greece. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Is the Senior System Engineer role at Just One | Recruitment & Executive Search Agency full-time or part-time?
This is listed as a Full time position. It is posted as a Senior System Engineer role at Just One | Recruitment & Executive Search Agency.
How do I apply for the Senior System Engineer position at Just One | Recruitment & Executive Search Agency?
Click the "Apply Now" button on this page. You will be redirected to Just One | Recruitment & Executive Search Agency's official application portal hosted on workable where you can submit your application directly.
When was the Senior System Engineer job at Just One | Recruitment & Executive Search Agency posted?
This Senior System Engineer position at Just One | Recruitment & Executive Search Agency was posted on Mar 17, 2026. Apply as soon as possible โ€” early applications are often reviewed first.
Senior System Engineer
Just One | Recruitment & Executive Search Agency
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