dsermar — Daniel Serrano Marín

Open to opportunitiesJerez de la Frontera, Spain · remote

Daniel Serrano MarínSystems & Infrastructure Engineer

Linux · Networking · AWS · Cloud · Automation

Junior systems and network administrator working on real infrastructure: MikroTik and Fortinet networks for 35+ clients, corporate VPNs, and Linux servers on AWS with CloudWatch monitoring and Lambda automation.

Building toward Cloud, DevOps and Cybersecurity

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Visual abstraction of the areas I work in — not a real network diagram.

Technical areas

Systems

  • Linux
  • Ubuntu Server
  • CentOS
  • VMware
  • Proxmox
  • Docker

Networking

  • MikroTik
  • Fortinet
  • Routing
  • VLANs
  • VPN

Cloud

  • AWS EC2
  • VPC
  • CloudWatch
  • Lambda
  • EventBridge
  • S3

Automation

  • Bash
  • Python
  • AWS Lambda
  • EventBridge
  • systemd

Security

  • Firewalls
  • VPN
  • NACLs
  • Security Groups
  • Linux hardening

01 / experience

Experience

One role, broad scope: networks, cloud, automation and endpoints for a portfolio of client companies.

Systems & Network Administrator

CadifoneJerez de la Frontera, Spain

client networks — MikroTik & Fortinet
35+
client PBX systems backed up to AWS
10+

Networking & perimeter security

  • Keep corporate networks built on MikroTik (routing, segmentation) and Fortinet firewalls available and secure for 35+ clients, handling traffic control and perimeter security.
  • Implement and manage secure remote access over VPN (SSTP and WireGuard).
  • MikroTik RouterOS
  • Fortinet
  • Routing
  • Segmentation
  • SSTP
  • WireGuard

Cloud migration & backup

  • Designed an automated AWS backup system for the Issabel PBX systems of 10+ clients, migrating their infrastructure from on-premises.
  • Deploy and administer Linux servers on AWS EC2, configuring VPC, NACLs and Security Groups.
  • AWS EC2
  • VPC
  • NACLs
  • Security Groups
  • Issabel
  • Linux

Automation & monitoring

  • Automate infrastructure tasks with Bash and AWS Lambda, scheduled through EventBridge.
  • Implemented AWS CloudWatch monitoring for logs, metrics and alerts.
  • Bash
  • AWS Lambda
  • EventBridge
  • CloudWatch

Containers & endpoints

  • Manage and deploy applications with Docker.
  • Administer corporate devices with Microsoft Entra ID and Intune.
  • Docker
  • Microsoft Entra ID
  • Intune

EducationHigher Vocational Degree in Network Systems Administration (ASIR) · IES Francisco Romero Vargas2023 — 2025

02 / projects

Projects

Built outside my day job, documented as engineering work: what the system does, how it is put together and what I built.

Explore my projects on GitHub

Source code, documentation and work in progress.

github.com/danielsm107

03 / skills

Skills

Marked items are the ones I use in my current role. The rest come from projects, lab work and training — kept separate on purpose.

Used in my current roleProjects, lab or training

Networking

  • MikroTik RouterOS (Used in my current role)
  • Routing (Used in my current role)
  • Network segmentation (Used in my current role)
  • Fortinet firewalls (Used in my current role)
  • SSTP VPN (Used in my current role)
  • WireGuard (Used in my current role)
  • Switching
  • VLANs

Cloud (AWS)

  • EC2 (Used in my current role)
  • VPC (Used in my current role)
  • CloudWatch (Used in my current role)
  • Lambda (Used in my current role)
  • EventBridge (Used in my current role)
  • S3

Systems

  • Linux (Used in my current role)
  • Docker (Used in my current role)
  • Microsoft Entra ID (Used in my current role)
  • Intune (Used in my current role)
  • Ubuntu Server
  • CentOS
  • Proxmox
  • VMware
  • Kubernetes (k3s / Minikube)
  • User & permission management

Security

  • NACLs (Used in my current role)
  • Security Groups (Used in my current role)
  • Perimeter security (Used in my current role)
  • Linux hardening
  • Cybersecurity principles

Scripting & other

  • Bash (Used in my current role)
  • Python
  • Shell
  • systemd
  • SQL
  • HTML / CSS

04 / certifications

Certifications & education

Certifications

Education

Higher Vocational Degree in Network Systems Administration (ASIR)

IES Francisco Romero Vargas · 2023 — 2025

Final project: license-plate recognition access control.

Languages

Spanish
Native
English
B2

05 / about

About

I’m a systems and network administrator with a background in network systems administration (ASIR). Since March 2025 I’ve worked at Cadifone on production infrastructure for client companies: MikroTik and Fortinet networks, VPN access, Linux servers on AWS and the automation and monitoring around them.

My foundation is systems and networking. Where I’m heading is cloud infrastructure, DevOps and security — I’m building that the same way I learned the rest: on real systems, with automation wherever a task repeats.

Current foundation

  • Systems
  • Networking
  • Linux
  • AWS

Current focus

  • Cloud infrastructure
  • Automation
  • DevOps
  • Cybersecurity

Open to opportunities

Let’s talk infrastructure.

I’m looking for roles in systems administration, networking, cloud, DevOps or infrastructure. Based in Jerez de la Frontera, Spain — available for remote work.

  • Systems Administration
  • Networking
  • Cloud
  • DevOps
  • Infrastructure