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Toss

Fintech super-app for payments and banking

Network Security Engineer

Network Engineering & AdministrationConfirmed live in the last 24 hours
Full-timeSeoul, South KoreaNo salary listedIn-person

About the Job

Requirements

  • Experience designing and building security network architectures optimized for large-scale traffic.
  • Experience analyzing, optimizing, and maintaining firewall policies.
  • Strong understanding of TCP/IP protocols and experience analyzing packets for troubleshooting.

Responsibilities

  • Build and operate network security infrastructure in on-premises and cloud environments, including designing and implementing VPCs, inline traffic inspection, network segmentation, and other security architecture.
  • Operate firewalls, VPNs, DDoS protection equipment, and network packet brokers (NPBs), including global security equipment such as Fortinet, in high-traffic service networks; monitor systems, respond to incidents, and change policies to improve service stability.
  • Use APIs, Python, Terraform, and Ansible to automate firewall-policy validation, deployment, changes, retirement, and recurring operational work.
  • Apply network-separation and access-control policies to meet financial-sector information-protection requirements, and systematically manage operational histories and evidence.
  • Improve traffic visibility and security controls for AI services and GPU workloads; use AI tools to improve the efficiency and accuracy of log analysis, policy review, and change-impact analysis.

Desired Qualifications

  • Experience integrating network security equipment with APIs, writing scripts such as Python scripts to automate work, or developing internal operations tools.
  • Experience managing network and security policies as code with Terraform or Ansible and validating policies in a pipeline.
  • Experience designing and building cloud inline security inspection architectures such as GWLB or Network Firewall, NVA, and service chaining.
  • Understanding of networking and segmentation in container environments such as EKS and GKE, including NetworkPolicy.
  • Experience achieving traffic visibility using flow logs, packet brokers, or SSL decryption-based analysis.
  • Experience automating security operations with AI or LLMs, or considering network controls for AI workloads.
  • Understanding of financial information-protection regulations and related implementation experience.

About the Company

Toss

Fintech super-app for payments and banking

Toss is a South Korean financial services platform that started as a peer-to-peer money transfer service and has grown into a digital 'super app' for personal finance. Its products are accessed through one mobile interface that unifies bank accounts, credit cards, loans, investments, and other financial services, including its own Toss Bank and Toss Securities. It differentiates itself by offering a broad, integrated ecosystem—combining digital banking, asset management, and brokerage services under one roof and running its own banking and securities units. Its goal is to become the leading consumer finance platform in South Korea while expanding its user base globally.

Company size
1,001-5,000
Company stage
Series G
Total funding
$1.5B
Headquarters
Seoul, South Korea
Founded
2011

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