Linux Systems Administrator / DevOps Engineer

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.