Principle Security Architect at ByDesign Secure, London, £750 per day

Opening: Join the Mission

At ByDesign Secure, we believe that world‑class security should not be an afterthought—it should be the foundation. We are an independent, outputs‑based consultancy delivering some of the UK public sector’s most complex and sensitive security‑critical systems.

We are currently supporting a landmark, cross‑government secure IT transformation, architecting private cloud environments from the ground up and modernising end‑user services that underpin national decision‑making. Our model prioritises impact, autonomy, and technical excellence over hierarchy and utilisation.

This is an opportunity for a Principal Security Architect to shape not only individual solutions, but the security posture, architectural standards, and strategic direction of nationally significant programmes.

About the Opportunity

As a Principal Security Architect, you will operate at the highest technical and strategic level within ByDesign Secure. You will define security strategy across multiple programmes, act as the senior security authority for complex and high‑risk environments, and influence decisions at executive and cross‑organisational levels.

This role is accountable for portfolio‑level coherence, architectural consistency, and organisational security maturity. You will set direction, resolve ambiguity, and provide leadership where guidance, precedent, or policy may be incomplete or competing.

What You’ll Be Doing

Strategy, Architecture & Vision

• Define and own enterprise‑level security principles, patterns, and reference architectures across programmes.
• Establish our roadmaps balance risk, delivery pragmatism, and strategic outcomes.
• Shape secure‑by‑design approaches for novel, sovereign, or highly constrained environments e.g. air‑gapped, classified, or cross‑domain systems.

Technical Authority & Assurance Leadership

• Act as the companies security authority for complex or high‑risk security decisions.
• Lead security assurance across multiple projects, including:
• Threat modelling and architectural risk assessment
• Design and solution reviews
• Set expectations and standards for security artefacts, assurance depth, and evidential quality.

Risk, Governance & Executive Engagement

• Enable risk‑based decision‑making at senior and executive levels, translating complex technical threats into clear, defensible options.
• Engage directly with SROs, Accreditors, CISOs, and policy stakeholders to resolve risk ownership and governance challenges.
• Navigate ambiguity across policy, standards, and operational constraints with a pragmatic, threat‑informed approach.

Leadership, Mentoring & Capability Building

• Provide technical leadership and mentorship to Senior and Security Architects.
• Set architectural standards and promote consistency across teams and projects.
• Champion a security‑first culture, raising the overall caliber of security engineering and architecture across the organisation.

Innovation & Thought Leadership

• Research, assess, and responsibly introduce emerging technologies where there is limited precedent or guidance.
• Represent ByDesign Secure as a trusted authority with clients and partners on complex security topics.

What You’ll Bring

Essential Skills & Experience

• Deep technical expertise across security architecture, infrastructure, cloud, identity, networks, and systems security.
• Strong working knowledge of NCSC standards and guidance, risk management approaches, and architectural frameworks.
• Proven experience operating in UK public sector or other highly regulated environments.
• Demonstrable delivery in classified, constrained, or limited‑connectivity systems.
• Ability to operate comfortably at solution, programme, and portfolio levels simultaneously.

Leadership & Communication

• Exceptional stakeholder management skills, with the ability to influence at executive and accreditor level.
• Confident decision‑maker able to balance delivery pressure against long‑term security outcomes.
• Clear, authoritative communicator—both written and verbal.

Qualifications

• Chartered Security Architect status is essential, with equivalent senior-level qualifications (e.g. CIISec / CIISP) considered desirable.
• Continued professional development aligned with senior technical leadership.

Bonus Points For

• Existing UK Government Security Clearance (SC or above)

Clearance Requirements:

• This role requires either an existing Security Clearance (SC level) or for one to be passed before commencement. There must be a willingness to undergo Developed Vetting (DV).

Job Types: Temporary, Fixed term contract (Outside of IR35)

Job Types: Fixed term contract, Temporary
Contract length: 12 months

Pay: £750.00 per day

Application question(s):

• Do you hold UK nationality? (Required due to client security restrictions)
• Do you currently hold active UK SC clearance?
• Are you eligible and willing to undergo UK SC/DV clearance for this role? (Applications without this cannot be considered)
• Does your delivery approach allow for on-site presence in London when required (typically around 3 days per week)?

Work Location: Hybrid remote in London