The Senior Infrastructure Engineer is responsible for the administration, maintenance, security, and continuous improvement of Cabaletta Bio's infrastructure and cloud platforms. This role provides hands-on technical support for AWS, Windows and Linux server environments, networking, firewalls, cybersecurity controls, backup and disaster recovery capabilities, and emerging platform technologies. Responsibilities: Infrastructure Administration Administer and support AWS cloud infrastructure, including EC2, VPCs, security groups, storage services, monitoring, and related cloud resources. Administer, maintain, and troubleshoot Windows Server and Linux server environments. Monitor infrastructure performance, availability, capacity, and reliability, and participate in planning, upgrades, patching, lifecycle management, and continuous improvement initiatives. Maintain infrastructure documentation, architecture diagrams, technical standards, and operating procedures, and assist with development and implementation of operational processes and technical best practices. Network and Connectivity Support, maintain, and troubleshoot network infrastructure, including firewalls, VPN connectivity, routing, DNS, DHCP, and wireless networking services, across cloud, server, and application environments. Assist with network design reviews and infrastructure improvements, and collaborate with managed service providers and infrastructure vendors to resolve complex technical issues. Cloud and Platform Services Design and support cloud-native and containerized workloads utilizing technologies such as Docker, ECS, EKS, and related platforms. Assist with application hosting, platform administration, and infrastructure services supporting internal business systems and scientific computing workloads, and participate in cloud modernization, infrastructure automation, and platform engineering initiatives. Support infrastructure requirements for data platforms, internal applications, and future AI-enabled solutions. Cybersecurity and Risk Management Implement and maintain infrastructure security controls and cybersecurity best practices. Support vulnerability remediation, system hardening, patch management, access controls, and security monitoring activities. Review infrastructure security recommendations and assist with implementation of corrective actions, collaborating with internal and external security resources to address identified risks. Support security audits, assessments, and compliance initiatives as required. Business Continuity and Disaster Recovery Support backup administration, recovery procedures, disaster recovery planning, and infrastructure resilience initiatives, including participation in DR exercises, testing activities, and business continuity planning. Maintain documentation supporting recovery procedures and infrastructure continuity requirements. Vendor and Service Coordination Serve as a technical point of contact for managed service providers, cloud partners, and infrastructure vendors. Coordinate technical activities, projects, escalations, and support requests across external partners, reviewing vendor and partner recommendations to provide technical input and implementation support. Customer Service and Collaboration Communicate effectively with business users, scientific teams, and technology partners, providing technical guidance and support during infrastructure-related incidents, projects, and technology initiatives. Partner closely with the Senior IT Systems Administrator and broader IT team to support enterprise technology services. Qualifications: