# Linux Systems Administrator / DevOps Engineer **Company:** [CodeForce](null/companies/w29HKGPswBNpG3edwgcdeL.md) **Location:** Karachi, Pakistan **Workplace:** hybrid **Employment type:** Full-time **Department:** IT Developement [Apply for this job](null/view/087b33d0-075d-41e8-a8de-53bda1693150) ## Description \# Linux Systems Administrator / DevOps Engineer \*\*Company:\*\* Dataphone \*\*Employment:\*\* Full-Time \*\*Location:\*\* Remote \## About Dataphone Dataphone operates a large-scale communications platform providing VoIP, PBX, Contact Center, SMS, AI voice, and business communication solutions. Our production environment includes Linux servers, Node.js/TypeScript applications, PM2, NGINX, PostgreSQL, FreeSWITCH, OpenSIPS, Docker, monitoring systems, and multiple customer-facing services. We are looking for a hands-on \*\*Linux Systems Administrator / DevOps Engineer\*\* who can take ownership of this infrastructure and help us keep it reliable, secure, and scalable. \## Responsibilities \### Linux Server Administration \* Manage production Debian/Ubuntu Linux servers \* Server provisioning, configuration, upgrades, patching, and hardening \* Manage CPU, memory, storage, processes, services, and networking \* Troubleshoot production outages and performance problems \* Manage SSH, users, permissions, sudo, and security \* Monitor server health and capacity \* Perform server migrations and maintenance with minimal downtime \* Maintain backups and disaster-recovery procedures \### Node.js / TypeScript Application Infrastructure \* Deploy and maintain Node.js/TypeScript applications \* Manage applications running under \*\*PM2\*\* \* Troubleshoot application crashes and memory leaks \* Monitor PM2 processes, CPU, memory, restarts, and logs \* Configure PM2 clusters and process management \* Perform application deployments and rollbacks \* Troubleshoot application/server interactions \* Work with developers to resolve production issues \* Help establish standardized deployment procedures You do \*\*not\*\* need to be a full-time application developer, but you must understand how Node.js applications run in production and be comfortable troubleshooting them. \### NGINX \* Configure and maintain NGINX \* Reverse proxy configuration \* SSL/TLS certificates \* HTTP/HTTPS routing \* Load balancing \* WebSocket proxying \* Connection and timeout configuration \* Troubleshoot 4xx/5xx errors \* Configure security headers and access controls \* Review NGINX access/error logs \* Optimize NGINX for production traffic \### PostgreSQL \* Manage production PostgreSQL servers \* Monitor database health and performance \* Troubleshoot connection issues \* Monitor CPU, memory, disk, locks, and connections \* Perform backups and restores \* Understand indexes and basic query performance \* Assist developers with database-related production issues \* Support replication/high-availability configurations \### VoIP Infrastructure \* Maintain and troubleshoot \*\*FreeSWITCH\*\* \* Maintain and troubleshoot \*\*OpenSIPS\*\* \* Troubleshoot SIP registration and call-routing problems \* Analyze SIP/RTP traffic \* Use Wireshark, tcpdump, and sngrep \* Troubleshoot NAT, RTP, codecs, packet loss, and latency \* Monitor telecom infrastructure \* Assist with scaling and load balancing \### Docker \* Manage Docker containers \* Troubleshoot containers that fail or restart \* Manage Docker networking and volumes \* Monitor container resources \* Maintain Docker-based production services \* Assist with containerizing additional applications \### Monitoring & Logging Maintain and improve monitoring across the infrastructure. Experience with: \* Grafana \* Prometheus \* Loki \* Netdata \* Linux system logs \* NGINX logs \* PM2 logs \* Application logs \* PostgreSQL monitoring \* FreeSWITCH/OpenSIPS logs The goal is to identify infrastructure problems \*\*before they become customer-impacting outages\*\*. \### Networking Strong understanding of: \* TCP/IP \* DNS \* HTTP/HTTPS \* WebSockets \* TCP/UDP \* NAT \* Firewalls \* Routing \* VLANs \* Public/private networking \* SIP/RTP networking \### Automation \* Bash scripting \* Python and/or JavaScript/TypeScript scripting \* Ansible or similar configuration-management tools \* Git \* Automate repetitive server-management tasks \* Create scripts for monitoring, deployment, maintenance, and troubleshooting \## Production Troubleshooting This role requires someone who can independently investigate problems such as: \* Node.js application repeatedly crashing \* PM2 process consuming excessive memory \* NGINX returning 502/504 errors \* WebSocket connections dropping \* PostgreSQL connections becoming exhausted \* Server running out of disk space \* FreeSWITCH CPU suddenly increasing \* SIP registrations failing \* Calls connecting without audio \* OpenSIPS routing failures \* Docker containers repeatedly restarting \* Network latency or packet loss \* SSL certificate expiration \* High server load \* Application deployment causing an outage The expectation is: \*\*Detect → Investigate → Identify root cause → Fix → Verify → Document\*\* \## Required Skills \### Must Have \* 3+ years Linux administration / DevOps experience \* Strong Debian/Ubuntu experience \* Strong Linux troubleshooting \* NGINX \* Node.js production environments \* PM2 \* PostgreSQL \* Docker \* Networking \* Bash scripting \* Git \* Monitoring/logging \* Strong production troubleshooting ability \### Preferred \* FreeSWITCH \* OpenSIPS \* FusionPBX \* SIP/RTP \* Wireshark \* sngrep \* Prometheus \* Grafana \* Loki \* Netdata \* Ansible \* Redis \* WebSockets \* CI/CD \* OVH/Vultr/AWS infrastructure \## Ideal Candidate The ideal candidate is \*\*not someone who only knows how to follow a checklist\*\*. We need someone who can receive a problem such as: \> "The API is slow and customers are getting intermittent 502 errors." …and independently work through: \*\*NGINX → PM2 → Node.js → PostgreSQL → Linux → Network\*\* to determine where the actual problem is. You should be comfortable logging into a server, examining processes and logs, running diagnostics, making a controlled change, verifying the result, and documenting the solution. \## Work Style We are looking for someone who: \* Takes ownership \* Works independently \* Is a strong problem solver \* Doesn't require constant supervision \* Can work during production incidents \* Communicates clearly \* Documents changes \* Understands the importance of uptime \* Knows when to escalate an issue \* Continuously improves infrastructure rather than simply maintaining it \## Technical Assessment Candidates may be required to complete a practical assessment covering: 1\. Linux troubleshooting 2\. NGINX configuration 3\. PM2/Node.js troubleshooting 4\. PostgreSQL troubleshooting 5\. Networking 6\. Docker 7\. FreeSWITCH/OpenSIPS fundamentals 8\. Monitoring and log analysis The assessment will focus on \*\*real-world troubleshooting and problem-solving rather than memorization\*\*. \## Compensation Compensation will be based on experience, technical ability, and location. Candidates with strong production experience in Linux, Node.js/PM2, NGINX, PostgreSQL, and VoIP infrastructure may qualify for higher compensation.