System Administrator (Linux / Unix)

About the role

We're looking for a System Administrator to own the servers, network and database layer that Paymentwall's payment platform runs on. This is hands-on infrastructure work: keeping high-availability systems up, fast and secure, from the operating system and firewall up to MySQL clusters and the web tier. Payments don't pause, so reliability and security are the job, not a side task. You'll work closely with our DevOps Engineer: you own the servers and the data layer, they own the container platform and delivery pipelines.

Key responsibilities

• Keep our high-availability server infrastructure healthy: monitoring, capacity planning and performance tuning.
• Administer Linux and BSD servers: provisioning, hardening, patching and upgrades.
• Run the database layer: highly available MySQL-family clusters, including replication, backups, restore tests, and query and server tuning.
• Manage network and perimeter security: host and network firewalls, intrusion prevention, and L4/L7 load balancers and proxies.
• Configure and tune the web and application tier: Nginx and the runtimes behind our polyglot backend (PHP, Go, Node.js and more).
• Maintain and regularly test backup and disaster-recovery procedures.
• Apply PCI DSS controls in day-to-day work: access management, logging, patch timelines and network segmentation.
• Set up servers and infrastructure for new company projects.
• Respond to incidents, find root causes and write them up. Take part in a shared on-call rotation.

About you

• 5+ years administering Linux servers in production.
• Advanced MySQL / MariaDB / Percona: performance tuning, replication and troubleshooting under load.
• Hands-on experience running multi-node or clustered database setups (e.g. Galera, group replication).
• Firewall and network security experience on Linux and/or BSD (e.g. iptables/nftables, pf/ipfw, fail2ban).
• Working knowledge of load balancers and proxies (e.g. HAProxy, LVS/IPVS, database proxies).
• Nginx configuration and tuning, and running application runtimes in production (PHP-FPM, Go, Node.js or similar).
• Solid Bash scripting.
• Monitoring with Prometheus and Alertmanager.
• Strong written and spoken English (B2 or higher) and good Chinese.
• Bachelor's degree in Computer Science, Information Technology or a related field, or equivalent practical experience.

Benefits

• Competitive compensation depending on experience and skills.
• Individual career path and growth opportunities.
• Work with an international team and gain in-depth knowledge about payments in different markets.
• Exposure to the fintech and gaming industries.
• Paid vacation.
• Office-based role in Kuala Lumpur Office at Menara Allianz Sentral.

About us

Paymentwall is a fast-growing fintech company that helps businesses expand globally through secure, seamless payment solutions. We're transparent, flexible, and focused on building trust and innovation across the global payments ecosystem. Our mission is simple: make global commerce smarter, safer, and more efficient.