Cyber Defence Network Engineer

ukgrantt; Greater London; On-site; GBP 60,000 - 85,000; Full time

Job summary

Grant Thornton's Cyber Defence Centre in the UK is seeking an experienced Network Engineer to join our hands-on team. You will deliver containment and recovery for live client security incidents and contribute to security assessments and hardening across cloud and on-premises environments.

You'll work with tools such as Microsoft 365, Entra ID, Azure, AWS, Active Directory, and CIS Benchmarks, aligning with NIST guidelines to design, implement and test resilient security solutions for diverse

Qualifications

• Experience in network security and incident response workflows.
• Exposure to cloud and on‑prem security configurations.
• Familiarity with CIS Benchmarks and NIST frameworks.

Responsibilities

• Deliver containment and recovery for live client security incidents.
• Perform security reviews and configuration hardening across cloud and on‑premises.
• Assess firewall, identity and access configurations; implement mitigations.
• Support remediation work aligned to security standards and best practices.

Skills

Network security

Incident response

Cloud security

Cyber defence

Tools

Microsoft 365

Entra ID

Azure

AWS

Active Directory

CIS Benchmarks

Prowler

ScubaGear

PingCastle

Job description

Alternatively, Grant Thornton

At Grant Thornton we do things differently - looking to the future, driving ambitious growth and pioneering positive change in our industry. Providing audit, tax and advisory services, we empower clients through strategic insight, curiosity, and genuine partnership. And we empower our people with real opportunity, an inclusive culture and work life balance. A true alternative.

With over 5,000 people in the UK, and a presence in 150 global markets, we're on an ambitious journey, from great to exceptional, and we need the best people to help us achieve our potential. And with that comes the opportunity to help redefine what our industry looks like, and what you want from your career.

Job Description:

Network Engineer, Cyber Defence Centre

Alternatively, Grant Thornton

At Grant Thornton we do things differently - looking to the future, driving ambitious growth and pioneering positive change in our industry. Providing audit, tax and advisory services, we empower clients through strategic insight, curiosity, and genuine partnership. And we empower our people with real opportunity, an inclusive culture and work life balance. A true alternative.

With over 5,000 people in the UK, and a presence in 150 global markets, we're on an ambitious journey, from great to exceptional, and we need the best people to help us achieve our potential. And with that comes the opportunity to help redefine what our industry looks like, and what you want from your career.

About us

The Grant Thornton Cyber Defence Centre is an award-winning* managed security services provider operating at the forefront of cyber security, using industry-leading technologies to protect and support our clients. Alongside our SOC capability, we have cutting-edge incident response teams delivering rapid cyber breach investigations for clients through insurance panels and direct engagements, supporting organisations at their most critical moments.

We invest heavily in our people, offering clear progression opportunities and encouraging initiative within a collaborative, cross-functional environment with a strong team ethos. Support is always available across the SecOps, DFIR, MSS and wider cyber teams.

We're seeking an experienced Network Engineer to join our Cyber Defence Centre. This is a hands‑on technical role that spans live incident response, security assessment and hardening, and the design and delivery of managed security solutions in client environments. You will be one of the people clients rely on to shut an attacker out of their estate and then help make sure it does not happen again.

A look into the role

As a Network Engineer within the Cyber Defence Centre, you will deliver the containment and recovery phases of live client incidents, and work on assessment, hardening and implementation engagements between them.

Incident response, containment and recovery

Delivering the containment and recovery phases of live client security incidents, including ransomware, business email compromise and perimeter device exploitation.

Isolating affected systems and accounts, restricting compromised identities, closing off attacker access routes, and preventing further spread across the estate.

Preserving logs and evidence for the forensic investigation team, and working alongside them as the investigation develops.

Supporting client recovery, including rebuild and restoration sequencing driven by business priority, and ensuring known weaknesses are not reintroduced.

Implementing the remediation and hardening work identified through the incident, where clients engage us to deliver it.

Working to the NIST Cyber Security Framework and incident response lifecycle, with CIS Benchmarks used for technical control recommendations.

Security assessment and hardening

Performing security reviews and configuration hardening across Microsoft 365 and Entra ID, Microsoft Azure, Amazon Web Services, on‑premise Active Directory, and perimeter firewall estates.

Conducting firewall security assessments across multiple vendor platforms: rule base review, management plane exposure, VPN and remote access configuration, IPS/IDS posture, logging, and firmware currency.

Assessing cloud configuration against CIS Benchmarks and NIST using tooling including Prowler, ScubaGear and PingCastle, and turning technical findings into prioritised, business‑contextualised remediation plans.

Reviewing third‑party software, cloud applications and SaaS platforms as part of supplier and technology assurance work.

Supporting client compliance and assurance requirements including GDPR, Cyber Essentials Plus and PCI DSS.

Security solution design and implementation

Designing and implementing security solutions in client environments, from discovery and requirements gathering through build, testing, rollout and handover.

Working as part of the delivery team on a Zero Trust access programme built on Netskope One SASE, covering Secure Web Gateway, CASB (inline and API), Priv