Senior System Administrator
Position: Senior Telco Infrastructure Administrator
Location: Warsaw, Poland
Working mode: Hybrid
About the company:
Our client specializes in delivering and developing advanced Contact Center solutions for large organizations. They support businesses in optimizing customer service processes through modern, multi-channel communication systems. The company integrates technologies such as voice, chat, email, and social media into unified platforms. They also focus on continuous improvement of implemented solutions, leveraging data analysis and emerging technologies like AI. Their approach combines consulting, implementation, and long-term client partnership.
About our client
Our client is a technology company specializing in delivering modern Customer Experience, Contact Center, and CRM solutions for medium-sized and enterprise organizations. The company supports clients in digital transformation by designing and implementing omnichannel communication platforms, AI-powered automation, and advanced system integrations. Its portfolio includes projects built on leading cloud and customer engagement technologies, helping businesses optimize customer service processes and improve operational efficiency. The organization combines deep technical expertise with a strong business focus, delivering scalable and secure solutions tailored to clients' needs.
About the role
We are looking for an experienced Senior Telco Infrastructure Administrator to join a team responsible for maintaining and developing mission-critical SaaS and telecommunications infrastructure. In this role, you will manage highly available production environments, optimize system performance, automate operational processes, and support modern VoIP platforms. You will work across Linux infrastructure, networking, virtualization, and cloud technologies while contributing to the evolution of scalable and resilient platforms. This is an excellent opportunity for engineers who enjoy solving complex infrastructure challenges and influencing technology decisions.
Key responsibilities
Administer, maintain, and develop Linux-based production infrastructure.
Ensure high availability, scalability, and performance of mission-critical systems.
Manage virtualization, containerization, and infrastructure automation.
Maintain monitoring, logging, and alerting platforms.
Support and optimize VoIP and telecommunications platforms.
Design and maintain network infrastructure, including routing, VPNs, and firewalls.
Troubleshoot complex production incidents and implement long-term improvements.
Collaborate with engineering teams on infrastructure modernization and architecture initiatives.
Requirements
Strong experience administering Linux environments (CentOS, Ubuntu, Debian).
Hands-on knowledge of virtualization technologies (KVM) and container platforms, including Proxmox, OpenVZ, or K3s.
Experience with Nginx, PostgreSQL, RabbitMQ, Redis, Consul, Elasticsearch/OpenSearch, and similar production technologies.
Practical knowledge of monitoring and logging solutions such as Zabbix and Graylog.
Experience supporting VoIP environments, including SIP, Kamailio, FreeSWITCH, SBCs, AudioCodes, or FreePBX.
Solid networking knowledge, including BGP, OSPF, VPNs, firewalls, QoS, and platforms such as VyOS, Juniper, or MikroTik.
Strong troubleshooting and problem-solving skills in production environments.
Experience with Microsoft technologies, cloud platforms (Azure or GCP), Hyper-V, WebRTC, or 3CX will be considered an advantage.
Offer
Employment based on an employment contract or B2B agreement.
Competitive salary of 20,000-25,000 PLN/month (depending on experience and employment type).
Opportunity to work with advanced SaaS and telecommunications infrastructure.
Real impact on infrastructure architecture and technology decisions.
Flexible hybrid working model after onboarding.
Stable, long-term cooperation in a highly skilled engineering team.
Professional development opportunities and exposure to modern cloud, networking, and VoIP technologies.