Freelance Software Engineer

This short-term contract role is focused on enhancing the security and functionality of RHEL 9 servers by enabling file uploads to while maintaining strict egress controls. The position requires a senior Linux and network security engineer to analyze outbound traffic, identify the necessary domains, IPs, and CIDRs for successful uploads, and develop a minimal, auditable, and secure outbound firewall ruleset. The engineer will also be responsible for implementing a command line prototype compatible with to validate the solution. The project is urgent and must be completed within 3–5 days, delivering a robust, well-documented solution suitable for enterprise environments.

Responsibilities

• Analyze outbound network traffic on RHEL 9 servers during upload attempts
• Identify all required domains, IP addresses, and CIDR ranges, including Cloudflare-backed endpoints
• Develop and document a minimal, secure, and auditable iptables ruleset to enable uploads while maintaining a default DROP policy
• Implement a command line prototype tool to validate file upload functionality to
• Ensure the solution is robust, enterprise-ready, and accompanied by clear documentation for future audits and maintenance
• Collaborate with stakeholders to ensure all security and operational requirements are met within the project timeline

Skills And Requirements

• Extensive experience with RHEL 9, Linux networking, and iptables configuration
• Deep understanding of egress firewall policies and best practices for secure server environments
• Proven ability to analyze and troubleshoot network traffic, including the use of tools such as tcpdump and Wireshark
• Familiarity with Cloudflare infrastructure and dynamic endpoint management
• Strong scripting skills for developing command line prototypes (e.g., Bash, Python)
• Ability to produce clear, comprehensive documentation for technical and non-technical audiences
• Experience working in enterprise or high-security environments
• Availability for immediate start and ability to deliver within a 3–5 day timeframe

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