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.