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- Tasks: Support and evolve IT infrastructure, ensuring stability and security for 200+ employees.
- Company: Join a dynamic team at a leading tech company in London.
- Benefits: Competitive pay, hands-on experience, and opportunities for professional growth.
- Other info: Collaborative culture with opportunities to shape standards and best practices.
- Why this job: Make a real impact while working with cutting-edge technologies in a fast-paced environment.
- Qualifications: Strong experience in networks, firewalls, and Microsoft 365; proactive problem-solving skills required.
The predicted salary is between 50000 - 65000 £ per year.
We’re looking for an experienced Senior System Administrator to join our Infrastructure team on a contract basis, helping us keep Reward’s IT estate stable, secure, and scalable as we continue to grow. You’ll play a key role in supporting and evolving the infrastructure that underpins our business from office networks and data centres to Microsoft 365, Intune, and endpoint management supporting 200+ employees across the organisation. This is a hands-on, infrastructure-heavy role, ideal for someone who enjoys ownership, problem solving, and working across a broad range of technologies in a fast-moving environment.
What you’ll be doing:
- Working onsite in our London office 3 days per week (rota with the team)
- Providing ad-hoc support to our Belfast office when required
- Owning and supporting office networks (LAN & Wi‑Fi) design, build, performance and troubleshooting
- Managing firewalls: rules, NAT, segmentation, VPNs and firmware
- Supporting switching and core network services (VLANs, routing, redundancy)
- Maintaining network architecture standards, DNS/DHCP and capacity planning
- Supporting our on-prem/data centre server estate (hardware, OS, lifecycle, upgrades)
- Attending the central London data centre as needed for installs, upgrades and BAU support
- Executing patching, backups, monitoring and alerting, with a focus on reliability and compliance
- Administering Microsoft 365 and Intune (policies, baselines, deployments)
- Improving tooling, dashboards, documentation and operational processes
- Supporting and collaborating with junior and mid-level SysAdmins
- Providing out-of-hours support where required (on call may follow)
- Assisting with desktop support via Zendesk to keep day-to-day operations running smoothly
- Helping maintain PCI‑DSS and ISO27001-aligned security standards
What we’re looking for:
- Strong hands-on experience with networks: LAN/Wi‑Fi, TCP/IP, DNS, DHCP, VLANs, routing & VPNs
- Solid firewall management experience (rules, NAT, segmentation)
- Excellent hardware and infrastructure troubleshooting skills
- Strong experience with switching, routing, uplinks and redundancy
- Practical experience supporting Microsoft 365 and Intune
- Experience in on-prem environments and data centre operations
- Confident managing backups, restores and retention
- Comfortable working with servers, networking components and infrastructure services
- Clear communicator with both technical and non-technical stakeholders
- Proactive, detail-oriented and comfortable working autonomously
- Happy operating in a high-change environment with evolving processes
Nice to have:
- Advanced Excel (PowerPivot, VBA, complex formulas)
- Python for automation or data wrangling
- Exposure to cloud technologies
- Experience with Power BI or Tableau
- Familiarity with AWS governance and compliance
- Background in retail, banking, CRM, loyalty or digital marketing
- Degree in Computer Science, Engineering, Mathematics or similar
A genuinely hands-on infrastructure-first contract role with exposure to a broad, modern tech estate and the opportunity to help shape standards, tooling and best practices. Join a collaborative team with real ownership and impact. If you’re a proactive SysAdmin who enjoys variety, responsibility, and improving how things work, apply now!
Senior System Administrator in London employer: Reward
Contact Detail:
Reward Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Senior System Administrator in London
✨Network Your Way In
Don’t underestimate the power of networking! Reach out to your connections in the industry, attend meetups, or join relevant online forums. You never know who might have a lead on that perfect Senior System Administrator role.
✨Show Off Your Skills
When you get the chance to chat with potential employers, make sure to highlight your hands-on experience with networks and firewalls. Share specific examples of how you've tackled challenges in past roles – it’ll show them you’re the real deal!
✨Be Proactive
If you see a job you like, don’t just sit back and wait for a response. Follow up with a friendly email or message to express your enthusiasm. It shows initiative and can help keep you top of mind for hiring managers.
✨Apply Through Our Website
We encourage you to apply directly through our website. It’s the best way to ensure your application gets seen by the right people. Plus, you’ll be one step closer to joining our awesome team!
We think you need these skills to ace Senior System Administrator in London
Some tips for your application 🫡
Tailor Your CV: Make sure your CV reflects the skills and experiences that match the Senior System Administrator role. Highlight your hands-on experience with networks, firewalls, and Microsoft 365 to show us you’re the right fit!
Craft a Compelling Cover Letter: Use your cover letter to tell us why you’re passionate about infrastructure and how your problem-solving skills can benefit our team. Be genuine and let your personality shine through!
Showcase Your Technical Skills: Don’t just list your technical skills; provide examples of how you’ve used them in past roles. Whether it’s managing firewalls or supporting data centre operations, we want to see your expertise in action.
Apply Through Our Website: We encourage you to apply directly through our website. It’s the best way for us to receive your application and ensures you don’t miss out on any important updates from our team!
How to prepare for a job interview at Reward
✨Know Your Tech Inside Out
Make sure you brush up on your knowledge of networks, firewalls, and Microsoft 365. Be ready to discuss specific technologies you've worked with, as well as any challenges you've faced and how you overcame them.
✨Showcase Problem-Solving Skills
Prepare examples of past situations where you had to troubleshoot complex issues. Highlight your thought process and the steps you took to resolve the problems, as this role is all about ownership and problem-solving.
✨Communicate Clearly
Practice explaining technical concepts in simple terms. You'll need to communicate with both technical and non-technical stakeholders, so being able to break down complex ideas will be a huge plus.
✨Demonstrate Proactivity
Think of ways you've improved processes or tools in your previous roles. This shows that you're not just reactive but also proactive in enhancing the infrastructure and operations, which is key for this position.