Senior Systems Administrator

Sharetru

4d•Remote

About The Position

Sharetru is a secure managed file transfer (MFT) platform trusted by organizations with high security, compliance, and availability requirements. We operate infrastructure across multiple data centers and network providers while supporting customers subject to SOC 2, HIPAA, and FedRAMP-aligned controls. Our environment is Linux-first, security-focused, and built for reliability at scale. This role is for someone who thrives in complex systems, values automation, and understands that production stability matters more than clever shortcuts. Why This Role Matters This role is critical to the reliability and security of Sharetru’s platform. The systems you manage directly support customer data, compliance commitments, and business continuity. We’re looking for someone who understands that good infrastructure is quiet, boring, and deliberate. What You'll Do As a Senior Systems Administrator, you will be responsible for the design, operation, hardening, and reliability of our Linux infrastructure across multiple networks and data centers including:

Requirements

7+ years of professional Linux systems administration experience
Strong experience with RHEL-based distributions (RHEL, Rocky, CentOS)
Deep understanding of Linux Networking (routing, firewalls, NAT, VPN concepts), system performance and troubleshooting, and filesystems, storage, and backups
Proven experience securing Linux systems in regulated environments
Experience with SELinux beyond permissive mode
Experience with iptables/nftables/ipset in production
Strong knowledge of TLS, certificates, and cryptography basics
Experience operating high-availability systems (clusters, failover, redundancy)
Solid scripting skills (Bash required; Python a strong plus)
Familiarity with configuration management (Ansible preferred)

Nice To Haves

Experience with FedRAMP or NIST 800-53–aligned environments
Experience with Percona XtraDB Cluster / Galera / ProxySQL / HAProxy
Experience in multi-datacenter or SaaS environments
Exposure to Proxmox, VMware, or similar virtualization platforms
Experience building or maintaining internal admin tooling
Experience supporting environments subject to SOC 2, HIPAA, or PCI.
Understanding of change management, access controls, and audit requirements
Comfortable producing documentation and evidence for auditors
Ability to make changes carefully in shared, customer-impacting systems
Strong troubleshooting and critical thinking skills
Comfortable working independently and owning systems end-to-end
Clear communicator who documents decisions and changes
Security-first mindset — you understand that “it works” is not enough
Calm under pressure during incidents and outages

Responsibilities

Administer and harden Red Hat Enterprise Linux/Rocky Linux systems across production, staging, and internal networks
Operate infrastructure spanning multiple data centers, including segmented networks, DMZs, and private backend tiers
Manage and secure services including: Apache / PHP-FPM SFTP / FTPS (ProFTPD or equivalent) MySQL / Percona (including Galera clusters and proxies) HAProxy / reverse proxies / WAF-style architectures
Design and maintain high-availability and fault-tolerant systems
Implement and maintain security controls: SELinux (enforcing, custom policies) iptables / nftables / ipset TLS hardening (FIPS-aware where applicable) MFA, access controls, and least-privilege enforcement
Support and contribute to compliance efforts (SOC 2, HIPAA, FedRAMP-aligned controls), including evidence collection and control validation
Automate system configuration and maintenance using Ansible, shell scripting, and/or Python
Troubleshoot complex production issues across OS, network, and application layers
Participate in change management, incident response, and root cause analysis
Collaborate closely with engineering, support, and compliance teams to keep systems stable, secure, and auditable
Log into systems, read logs, understand packet flow, and know why something is not working as expected.