# 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
*