# Senior System Engineer

**Company:** [JUST ONE | Recruitment & Executive Search agency](http://jobs.workable.com/companies/ib797vH3Q2pSZH4AY2muow.md)
**Location:** Athens, Greece
**Workplace:** hybrid
**Employment type:** Full-time

[Apply for this job](http://jobs.workable.com/view/0404b14b-e2e7-4267-9d7d-12599d69402e)

## Description

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.

## Requirements

-   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.

## Benefits

-   Competitive remuneration package
-   Private Medical Insurance package
-   Continuous learning in new technologies
-   Opportunity to work in large-scale projects with talented people