Information technology security specialist

Key Responsibilities Security & Compliance Alignment • Ensure DDI architectures align with: • ISSP System Management Standards • Regulatory and audit requirements • Internal security architecture principles • Support B2B and third‑party connectivity designs by: • Enforcing DNS/DHCP/NTP segregation in DMZ and partner zones • Supporting secure onboarding of external partners • Participate in: • Architecture Review Board (ARB) discussions • Security risk assessments • Exception and remediation planning DNS (Internal, External & Recursive) • Design, deploy, and manage Authoritative External DNS for: • Internet‑facing applications • B2B / third‑party integrations • External DMZ services • Operate and secure Recursive DNS infrastructure: • Enforce security controls (DNS filtering, logging, anomaly detection) • Prevent DNS‑based attacks (exfiltration, tunneling, amplification) • Manage Internal DNS services supporting: • Core enterprise systems • Data centre workloads • Hybrid and cloud platforms • Implement DNS security best practices: • Split‑horizon DNS • Restricted zone transfers • Secure delegation and access controls DHCP & IP Address Management (IPAM) • Design and operate enterprise DHCP services across: • Data centres • DMZ and B2B zones • Network‑segmented environments • Maintain accurate IPAM records to support: • Security audits • Incident response • Capacity planning and compliance • Integrate DHCP/IPAM with: • Network security controls • Automation workflows • Change management processes NTP (Time Synchronization Services) • Manage and secure NTP infrastructure for: • Network devices • Security platforms • Servers and applications • Ensure accurate, trusted time sources to support: • Security logging and forensics • Compliance and audit requirements • Design resilient and segmented NTP architecture for internal, DMZ, and external-facing systems Operations & Engineering Excellence • Act as L3/L4 subject matter expert for DDI‑related incidents • Drive standardization and automation of DDI services • Improve operational resilience, monitoring, and alerting • Work closely with: • Firewall & WAF engineers • Cloud security teams • Application and infrastructure teams • Provide clear technical documentation and design artefacts Required Skills & Experience • 10 to 15 years of relevant work experience in information security • Engineering graduate with strong hands on expertise in DDI solutions (DNS, DHCP, NTP), relevant product certifications, and a solid understanding of industry standard RFCs governing these protocols. Security & Architecture • Strong understanding of: • DNS‑based attack vectors • Segmentation and trust boundaries • Secure service exposure principles • Ability to design secure-by-default DDI architectures • Comfortable engaging in security reviews and audits Technical Skills • Strong hands‑on experience with DNS, DHCP, IPAM, and NTP in large enterprise environments • Experience supporting Internet‑facing and B2B architectures • Solid understanding of: • Network security principles • DMZ design patterns • External partner connectivity • Familiarity with security controls such as firewalls, WAF, IDS/IPS • Experience with DDI platforms (vendor‑agnostic; Infoblox / BlueCat / equivalent) This is in partnership with the Employment and Employability Institute Pte Ltd (“e2i”). e2i is the empowering network for workers and employers seeking employment and employability solutions. e2i serves as a bridge between workers and employers, connecting with workers to offer job security through job-matching, career guidance, and skills upgrading services, nationwide, and partnering with employers to address their manpower needs through recruitment, training, and job redesign solutions. e2i is a tripartite initiative of the National Trades Union Congress set up to support nation-wide manpower and skills upgrading initiatives. By applying for this role, you consent to Quesscorp Singapore’s PDPA and e2i’s PDPA. Disclaimer: The company is committed to ensuring the privacy and security of your information. By submitting this form, you consent to the collection, processing, and retention of the information you provide. The data collected (which may include your contact details, educational background, work experience and skills) will be used solely for the purpose of evaluating your qualifications for the position you're applying for. Your data will be stored securely and retained for the duration necessary to fulfill our hiring process. If you are not selected for the position, your data will be kept on file for a limited period in case future opportunities arise. You have the right to access, correct, or delete your data at any time by contacting us at Quess Singapore | A Leading Staffing Services Provider in Singapore(quesscorp.sg)