Sr Backend Engineer (PHP/Python/Go, Network)

The Senior Software Engineer, GeoGuard contributes to the success of the GeoGuard team by leading the design and implementation of advanced VPN detection, proxy identification, and IP threat investigation solutions. This role combines deep technical development expertise with specialized network security knowledge to combat emerging IP spoofing threats and anonymization technologies. Reporting directly to the Manager, Technical Product, this position develops and maintains GeoGuard's core products by architecting sophisticated detection algorithms, researching emerging VPN/proxy technologies, and implementing robust countermeasures against IP obfuscation techniques. Key ResponsibilitiesAccountabilitiesLead technical research and development of VPN/proxy detection algorithms and IP threat assessment systemsProvide technical guidance to developers on network security, IP geolocation, and threat detection methodologiesResearch emerging VPN services, proxy networks, and IP spoofing techniques; analyze their methods and develop countermeasuresDesign and architect scalable solutions for real-time IP threat analysis and geolocation verificationConduct technical reviews of threat detection models and validation algorithms for customer releasesEstablish and maintain best practices for cybersecurity-focused development within the teamImmediately escalate critical security vulnerabilities or emerging threat vectors that could impact product effectivenessResponsibilitiesVPN/Proxy Investigation & Research:Continuously monitor and analyze new VPN providers, proxy services, and anonymization toolsInvestigate IP allocation patterns, hosting provider behaviors, and network infrastructure changesDevelop and maintain comprehensive databases of known VPN/proxy IP ranges and behavioral signaturesResearch emerging threats including residential proxies, mobile proxies, and distributed proxy networksMonitor darkweb marketplaces and security forums for emerging proxy/VPN trendsPerform deep packet analysis and network traffic pattern recognitionTechnical Development:Develop and maintain GeoGuard's system using PHP, Python, and/or GoOptimize VPN/ Proxy detection algorithmsSystem Architecture & Operations:Design scalable infrastructure to handle millions of IP lookups per dayImplement monitoring and alerting systems for detection accuracy and system performanceAnalyze production incidents related to false positives/negatives in threat detectionCollaborate with DevOps team on deployment of detection rule updates and model improvementsCustomer & Stakeholder Support:Investigate customer-reported bypass attempts and develop rapid response solutionsProvide technical expertise during customer security consultationsSupport sales engineering team with technical demonstrations and proof-of-conceptsDocument threat analysis findings and detection methodologies for internal and customer useIndustry Intelligence & Collaboration:Maintain relationships with cybersecurity vendors, threat intelligence providers, and ISPsMonitor industry threat reports, security advisories, and academic researchParticipate in cybersecurity conferences and forums to stay current with threat landscapeContribute to open-source security tools and research when appropriate