Senior Microsoft Enterprise Systems Engineer

ByDesign Secure Systems Ltd; West of England; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

ByDesign Secure Systems Ltd. is seeking a Senior Microsoft Enterprise Systems Engineer to design, deploy and operate secure Microsoft services within large-scale government transformation programmes.

You will help build core collaboration and identity platforms in air-gapped, highly secure environments. Bring 7+ years of enterprise MS infrastructure experience, with hands-on AD DS, Exchange Server SE and SharePoint Server SE expertise.

Qualifications

• 7+ years Microsoft enterprise infrastructure experience.
• Strong hands-on experience with Active Directory DS.
• Strong experience with Exchange Server SE.
• Strong experience with SharePoint Server SE.
• Experience operating in disconnected or restricted-network environments.
• Experience working in regulated or classified environments.
• Strong technical documentation and stakeholder communication skills.
• Strong written communication for high-quality design outputs.

Responsibilities

• Deploy, administer and harden Active Directory Domain Services (AD DS).
• Deploy and support Exchange Server SE.
• Deploy and support SharePoint Server SE.
• Design and implement enterprise Microsoft infrastructure services within secure and air-gapped environments.
• Enforce security controls including GPOs, RBAC and platform hardening standards.
• Operate and maintain business-critical services in classified environments.
• Collaborate with security, architecture and engineering teams to deliver enterprise solutions.
• Produce technical designs, implementation plans and service documentation.
• Support governance activities and Technical Design Authority (TDA) reviews.
• Develop HLDs, CLDs, LLDs, operational procedures and runbooks.

Skills

Active Directory DS

Exchange Server SE

SharePoint Server SE

Disconnected environments

Regulated environments

Technical documentation

Stakeholder communication

Strong communicator

Job description

Senior Microsoft Enterprise Systems Engineer

This role is delivered within secure environments. Candidates must hold active SC/DV clearance and hold UK citizenship.

Join the Mission

At ByDesign Secure, we believe that world-class security shouldn't be an afterthought—it should be the foundation. We are an independent, outputs-based consultancy dedicated to solving the most complex data assurance challenges in the UK public sector. Currently, we working on a landmark transformation of a cross-government secure IT system. This is an exciting opportunity to help engineer a private cloud environment from the ground up and modernize the end-user services that power national decision-making. We don't believe in "billing by the hour" or rigid hierarchies; we are a lean, expert team focused on delivering high-impact technical outcomes. If you are a self-starter who thrives on autonomy and wants to see your engineering or architectural decisions shape the future of sovereign security, we want to talk to you.

About the Opportunity

We're looking for an experienced Senior Microsoft Enterprise Systems Engineer to join our team, helping design, deploy and operate secure Microsoft enterprise services within a large-scale government transformation programme. You will play a key role in building and maintaining core collaboration and identity platforms within highly secure, disconnected environments.

What You’ll Be Doing

• Deploy, administer and harden Active Directory Domain Services (AD DS).
• Deploy and support Exchange Server SE.
• Deploy and support SharePoint Server SE.
• Design and implement enterprise Microsoft infrastructure services within secure and air-gapped environments.
• Enforce security controls including GPOs, RBAC and platform hardening standards.
• Operate and maintain business-critical services in classified environments.
• Collaborate with security, architecture and engineering teams to deliver enterprise solutions.
• Produce technical designs, implementation plans and service documentation.
• Support governance activities and Technical Design Authority (TDA) reviews.
• Develop HLDs, CLDs, LLDs, operational procedures and runbooks.

What You’ll Bring

• 7+ years Microsoft enterprise infrastructure experience.
• Strong hands-on experience with Active Directory DS.
• Strong experience with Exchange Server SE.
• Strong experience with SharePoint Server SE.
• Experience operating in disconnected or restricted-network environments.
• Experience working in regulated or classified environments.
• Strong technical documentation and stakeholder communication skills.
• Strong communicator — able to bridge technical and non-technical stakeholders effectively.
• Good standard of written communication to enable high-quality design outputs to be produced.

Bonus Points For

• Prior experience working on government classified systems or within secure data centre environments.
• Experience of configuring and using AI technologies within cloud environments.
• Familiarity with NCSC guidance, UK Government cloud policies, or cross-domain architectures.
• Microsoft Azure, Microsoft 365, or other relevant cloud certifications
• Existing DV clearance.

Why This Role?

• Work on high-impact, nationally significant projects that make a real difference.
• Join a trusted specialist integrator with a proven record of secure delivery into UK Government.
• Be part of a multi-year programme offering long-term stability and genuine career growth.

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).

Work Location:

Hybrid remote in London / Bristol

Job Types:

Temporary, Fixed term contract (outside of IR35)

Screener Questions:

• 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 or Bristol when required (typically 3 days per week)?