Security Cleared DevSecOps Consultant - Senior

Onyx-Conseil; England; Hybrid; GBP 55,000 - 75,000; Full time

Job summary

A leader in defence and national security is seeking a DevSecOps Software Engineer to develop secure software solutions. This role offers a flexible working model, competitive salary and benefits, and the opportunity to work in a collaborative environment on mission-critical systems. Candidates must hold or be eligible for UK SC clearance.

Benefits

Competitive salary

Annual bonus

Private healthcare

Generous pension

25 days holiday plus birthday off

Paid volunteering days

Qualifications

• Strong experience in secure software development within Agile teams.
• Proficiency in one or more programming languages: Python, C#, Go.
• Solid understanding of the systems engineering lifecycle.

Responsibilities

• Develop secure software solutions using modern languages.
• Operate as a cross-functional engineer within an Agile DevSecOps team.
• Engage with stakeholders to understand technical requirements.

Skills

Secure software development

Python

C#

Go

Systems engineering

Networking fundamentals

Scripting (PowerShell, Bash, VBScript)

Problem-solving

Education

Degree in software engineering or related field

Tools

Balsamiq

AWS

Azure

Job description

DevSecOps Software Engineer

Sector: Defence & National Security

Clearance Required: SC clearance (or eligibility to obtain higher UK security clearance)

Employment Type: Permanent

Working Model: Flexible - remote, office, or client site (as required)

Salary & Benefits: Competitive salary + annual bonus, generous pension, private healthcare, 25 days holiday + birthday off, paid volunteering days, reservist leave, and more.

Role Overview

This is a unique opportunity to join a high-performing DevSecOps team delivering secure, mission-critical systems for the defence and national security ecosystem. The role is suited to a software engineer with a strong understanding of secure development practices, Agile delivery, and systems engineering principles. You'll work across the full lifecycle-from concept and requirements through design, build, integration, testing, and deployment-within a collaborative, multidisciplinary environment.

Key Responsibilities

• Develop secure software solutions using Python, C#, Go, and other modern languages.
• Operate as a cross-functional engineer within an Agile DevSecOps team.
• Engage with stakeholders to understand and refine technical requirements.
• Design, code, integrate, test, and deploy software in secure environments.
• Produce and execute software and integration tests.
• Identify and resolve bugs and deployment issues.
• Demonstrate software functionality to clients and stakeholders.
• Document technical work and support knowledge transfer to junior team members.
• Contribute to continuous improvement and adoption of new technologies.
• Participate in lessons learned and best practice sharing across teams.

Essential Skills & Experience

• Strong experience in secure software development within Agile teams.
• Proficiency in one or more programming languages: Python, C#, Go.
• Solid understanding of the systems engineering lifecycle.
• Experience working on large, complex, and secure systems.
• Knowledge of APIs and data architecture.
• Strong grasp of networking fundamentals and the networking stack.
• Scripting experience with PowerShell, Bash, or VBScript.
• Experience with software release audits (as developer or auditor).
• Ability to wireframe UI/UX designs using tools like Balsamiq.
• Excellent problem-solving skills in secure environments.
• Strong verbal and written communication skills.
• Willingness to work out of hours occasionally when required.

Desirable Qualifications & Experience

• Degree (or equivalent) in software engineering, systems engineering, or related field.
• Experience designing solutions to meet client requirements.
• Cloud platform accreditation (AWS, Azure) in DevOps or administration.
• CREST certification or equivalent security qualification.
• Chartered IT Professional status or equivalent.
• Hands‑on experience with UI/UX design and implementation.

Security Clearance

Due to the nature of the work, candidates must hold or be eligible to obtain UK SC clearance. Willingness to undergo higher levels of clearance is essential.

What You’ll Get in Return

• Competitive salary and annual bonus scheme.
• Generous pension and life assurance.
• 25 days annual leave plus your birthday off.
• Options to buy and sell holiday.
• 10 days additional leave for military reservists.
• Up to 2 days of paid volunteering per year.
• Individual Doctor@Hand healthcare cover.
• Genuine flexible working - remote, office, or client site.
• Access to the latest secure technologies.
• Investment in personal development and career progression.
• A vibrant and inclusive social scene.

About the Organisation

The client is a trusted leader in defence and national security, delivering secure digital capabilities and systems that support critical operations. Known for technical excellence and innovation, they offer a collaborative environment where engineers work on impactful projects using cutting‑edge technologies. With a strong focus on professional development, flexible working, and employee well‑being, this is a unique opportunity to contribute to national security while advancing your career.