Senior Linux System Administrator to $4500

About us:

Paysera is the first fintech company in Lithuania and an EU-licensed e-money institution. We provide fast, convenient, and affordable financial services globally. Our services range from a payment gateway for e-shops, a finance management app, money transfers, and a parcel locker network.
With over 1 million app downloads and growing, we aim to become an industry-leading super app that provides financial and lifestyle services across the globe. At Paysera, we are a start-up-minded team, which means we thrive in a fast-paced environment and seek open communication while placing great focus on upholding our core company values. Join our vibrant international team of over 700+ people across 20+ cities, worldwide.

Role Overview

Title: Linux System Administrator
Level: Senior
Team: IT Infrastructure (6 members)
Reports To: Head of IT Operations
Purpose: To manage, secure, and optimize Paysera’s global Linux-based infrastructure, ensuring high availability, scalability, and security for all core business services across multiple data centers.

Key Responsibilities

• [R1] Manage and maintain ~400 Ubuntu/Debian-based virtual machines in production using VMware ESXi, Proxmox, and KVM.
• [R2] Support and optimize MariaDB, PostgreSQL, InfluxDB, Redis, and RabbitMQ in production environments of multi-terabyte scale.
• [R3] Monitor infrastructure health using Zabbix, Prometheus, InfluxDB, and APM tools, ensuring SLA uptime compliance and incident resolution within defined response times.
• [R4] Troubleshoot infrastructure-related incidents, escalating as needed, and perform planned maintenance with minimal downtime.
• [R5] Automate deployments and configurations using Ansible, Terraform, and Helm for consistent and repeatable environments.
• [R6] Implement and maintain operating system security hardening measures and integrate with SIEM solutions for proactive threat detection.
• [R7] Participate in installing and configuring basic infrastructure services for a new data center.
• [R8] Lead the migration of core business services between old and new data centers with zero critical service downtime.
• [R9] Document system configurations, SOPs (Standard Operating Procedures), and change logs for audit readiness.
• [R10] Collaborate with cross-functional teams to align infrastructure changes with business continuity plans.

Must-Have Requirements

• [Q1] Minimum 4 years of Linux system administration in production environments with 100+ servers
• [Q2] Proven experience with virtualization platforms (VMware ESXi, Proxmox, KVM) managing 100+ VMs concurrently.
• [Q3] Proficiency in administering DBs MariaDB, PostgreSQL, Redis.
• [Q4] Ability to write and maintain automation scripts in Bash, Python, Go, and use Terraform & Ansible for infrastructure-as-code.
• [Q5] Solid knowledge of the OSI model and experience with ACLs, VPNs, and firewalls at a junior-to-mid level.
• [Q6] Demonstrated experience with infrastructure monitoring tools (Zabbix, Prometheus, InfluxDB) for environments with 99.9%+ uptime targets.
• [Q7] English language skills at B2 level or higher for technical documentation and cross-team communication.
• [Q8] Stable career history with average tenure of 2+ years per role over the past 5 years.

Nice-to-Have Qualifications

• [N1] Experience deploying and managing Kubernetes clusters and Docker containers.
• [N2] CI/CD pipeline management experience using GitLab CI.
• [N3] Administration experience with cloud platforms (AWS, GCP).
• [N4] Experience configuring and managing CDN services such as CloudFlare or Akamai.
• [N5] Production experience with RabbitMQ and Kafka

Work Conditions & Contract Info

• [W1] Employment type: B2B contract or Direct Employment.
• [W2] Location: Fully remote across the EU; hybrid (3–4 days/week in office) for Office-based candidates.
• [W3] Core hours: 08:00–20:00 EEST (flexible scheduling within this window).
• [W4] Contract length: 1+ years.
• [W5] Compensation: €15–€25/hour gross, depending on qualifications.
• [W6] Optimal Start date: 2025-09-01.
• [W7] Interview process: 1-2 stages.