Senior Network Security Engineer, Fintech

Optasia is a real-time financial intelligence company. We build precision intelligence that unlocks financial opportunity at scale, running millions of automated credit decisions every day across high-growth markets where formal credit data is limited. Our AI-powered platform turns permitted behavioural data and real-time signals into precise, responsible credit decisions.

Embedded within the systems of telcos, banks, digital wallets and other partners, it helps them extend relevant financial services to more people while maintaining strong portfolio control and opens profitable new segments that were previously out of reach. This is how Optasia turns potential into financial progress, responsibly and at scale.

As a member of the Network Security Engineering team in Optasia, your primary objective is to ensure the stability, security, performance, and continuous improvement of the organization’s enterprise network and security infrastructure by designing, implementing, maintaining, and supporting core networking and security services across production and corporate environments.

What you will do

• Participate in the design, implementation, and continuous improvement of enterprise network and security solutions.
• Deploy, configure, and maintain enterprise network infrastructure, including switches, routers, wireless networks, and next-generation firewalls.
• Administer and support security technologies such as firewalls, VPNs, network access control, and network segmentation.
• Monitor network and security infrastructure to ensure high availability, performance, and resilience.
• Perform network hardening, vulnerability remediation, and security improvement activities.
• Investigate and troubleshoot complex network and security incidents, including root cause analysis where required.
• Support Layer 2 and Layer 3 network services, including VLANs, STP, LACP, routing, DNS, DHCP, and TCP/IP services.
• Manage and support VPN technologies, including IPsec VPN and SSL VPN solutions.
• Collaborate with internal technical teams, project managers, and external vendors to deliver infrastructure and security projects.
• Participate in infrastructure upgrades, migrations, disaster recovery planning, and operational improvement initiatives.
• Ensure network and security solutions comply with organizational policies and industry best practices.
• Provide technical support and guidance to other IT teams when required.
• Maintain accurate technical documentation, network diagrams, configuration standards, changes, and operational procedures.

What you will bring

• 5+ years of hands-on experience as a Network Engineer or Network Security Engineer.
• Strong understanding of enterprise networking principles and protocols, including TCP/IP, DNS, DHCP, VLANs, and IEEE 802.1X.
• Strong knowledge of Layer 2 technologies, including Spanning Tree Protocol and Link Aggregation Control Protocol.
• Good understanding of Layer 3 routing technologies and protocols.
• Strong knowledge of VPN technologies, including IPsec VPN and SSL VPN.
• Extensive experience with Cisco networking technologies, including switching, routing, and enterprise campus networks.
• Hands-on experience with enterprise firewall platforms such as Cisco ASA, Cisco Firepower, and Fortinet FortiGate.
• Familiarity with enterprise wireless networking solutions.
• Working knowledge of Windows and Linux operating systems.
• Experience with network monitoring, troubleshooting, and diagnostic tools.
• Understanding of network security best practices, including segmentation, zero-trust principles, and secure network architecture.
• Familiarity with authentication and identity services such as RADIUS, Active Directory, and LDAP.
• Experience with vulnerability assessment, hardening, and remediation processes.
• Ability to create and maintain technical documentation, network diagrams, configuration standards, and standard operating procedures.
• Excellent problem-solving, analytical, communication, and collaboration skills.
• Professional certifications such as Cisco CCNP Enterprise, CCNP Security, Fortinet NSE, FCP, or FCSS will be considered an advantage.

Why Optasia?

Optasia is a high-growth, AI-powered financial infrastructure platform serving over 432 million users in emerging markets across Africa and Asia. By harnessing the power of AI and real-time data we unlock financial opportunities for customers. We have been recognized as a top fintech by Forbes Middle East, culminating in a successful JSE listing in 2025.

At Optasia, our global team builds the tech, products and services which will change the game for the world's unbanked population. We empower our people by offering unique employee experiences and support individual careers by prioritizing well-being and embracing flexibility.

Benefits include:

• Work from anywhere policy
• Competitive remuneration package
• Extra day off on your birthday
• Performance-based bonus scheme
• All the tech gear you need to work smart