Matías Querejeta
ESEN

Seeking an AppSec or SOC / blue team role

Matías Querejeta

  • Application Security
  • SOC / Blue Team
  • Penetration Testing

Full-stack developer with 4 years of experience in .NET and React, on projects for logistics, finance, education and customer experience companies, moving into application security and blue team.

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LinkedInGitHub
role
Software Developer
focus
AppSec · Blue Team
based
Mar del Plata, AR
eJPTv2
exam Nov. 2026

About

My background is in full-stack development, and I want to bring that foundation into security: knowing how software is built helps me understand how it breaks and how to fix it. I'm aiming for an application security or SOC / blue team role: I bring the developer's perspective and the attacker's (I'm preparing for the eJPTv2 exam in November) to understand, detect and fix threats.

Experience

  1. OpenDev Pro

    Jan 2026 - Presentcurrent

    Software Developer (Full-Stack .NET/React) - Production Bugs team

    • Outsourced to a major logistics company: I fix in code the vulnerabilities reported by penetration tests on its web and API applications (SQL injection, broken access control, insecure file upload, hardcoded credentials, weak authentication, insecure configuration).
    • I continuously resolve production issues, prioritizing by urgency and impact to restore service as quickly as possible. I review logs in Rancher / Kubernetes and in the database.
    • Proposed and designed a SAST/DAST plan for CI/CD pipelines: Semgrep for static analysis and OWASP ZAP for dynamic testing in non-production environments.
    • Full-stack development with .NET Core and React. We work with Spec-Driven Development (SDD) using Claude, with tasks and time tracking in Jira.

  2. LanguagesOK

    Aug 2026 - Sep 2026freelance

    Freelance Full-Stack Developer

    • Private management web platform for an English teacher and her students, built in one month: student sign-up and deactivation, PDF, audio and YouTube materials, and class building with drag-and-drop.
    • Next.js
    • React
    • Supabase
    • S3

  3. LinkIT

    Aug 2025 - Jan 2026

    Freelance Full-Stack .NET Developer

    • Built features for an educational management platform for institutions in Chile using .NET and Blazor on Azure.

  4. Aiotek - Software Factory

    Nov 2024 - Jan 2026

    Full-Stack .NET Developer

    • Developed web solutions for the client Yoizen using .NET, AngularJS, ASPX and jQuery.
    • Integrated social media APIs (WhatsApp Business, X, Facebook) and maintained legacy systems, improving performance and stability.
    • Worked with deployments to Azure and set up local IIS environments to run and test the applications.

  5. Ripsa Red de Pagos

    Nov 2022 - Oct 2024

    Full-Stack Developer

    • Built backend (.NET Core, RESTful APIs, SQL Server) and frontend (Blazor, React, Next.js) for a payments company.
    • Implemented authentication and authorization with IdentityServer4 and integrated third-party payment gateways.
    • Responsible for all application deployments, publishing to IIS. Used Grafana for monitoring and testing.

Personal projects

ojoalclic-ejpt

open-source lab · Oct 2026

One-command lab to practice the vulnerabilities covered in the eJPTv2 course and certification. A dual-homed gateway and an isolated internal network (Linux and Windows) with the exam's services. Includes an optional blue-team view with Wazuh agents.

  • Vagrant
  • VirtualBox
  • Docker
  • Bash
GitHub

Home SOC lab

personal project · Oct 2026

A home SOC to practice detection and response: Wazuh (SIEM), Sysmon and Suricata (IDS) watch my PC and the victims of my pentest lab, and critical alerts reach me on Telegram. I wrote 27 detection rules mapped to MITRE ATT&CK (endpoint and Active Directory), validated with simulations, and maintain them as code in Sigma with 32 tests and conversion to Splunk, KQL and Elastic.

  • Wazuh
  • Sysmon
  • Suricata
  • Sigma
  • MITRE ATT&CK
  • Python

Ojo al clic

outreach

Instagram channel sharing cybersecurity knowledge with both technical and non-technical people.

@ojoalclic

Hands-on security

INE · eJPTv2all labs completed

eJPTv2 preparation labs

100+ labs · 12 CTFs

Modules

Reconnaissance & enumeration · Vulnerability assessment · Windows & Linux host attacks · Network attacks · Metasploit Framework · Exploitation · Post-exploitation & pivoting · Social engineering · Web application pentesting

Services enumerated and exploited

SMB · FTP · HTTP · WebDAV · SSH · SMTP · SNMP · RDP · WinRM · MySQL · MSSQL · rsync · DNS

UTN · 2022Technical analyst

Full penetration test, Ethical Hacking course

Team of six (me + 5 teammates) against a fictitious company.

Phases

Reconnaissance & OSINT · Scanning & enumeration · WordPress exploitation · Privilege escalation · Password attacks / brute force · Network sniffing · Executive & technical reports with severity ratings and remediation

Download full report (PDF)

Academic exercise against a fictitious company. PDF in Spanish, with the teammates' names removed.

Research

mequerejeta/bugbounty-ops

How I organize my research: a versioned repo with the methodology I follow on every bug bounty program.

It's my working framework while I learn bug bounty, not a log of findings.

methodology/Checklists by vulnerability class

Based on the OWASP WSTG.

  • IDOR / broken access
  • Auth / session
  • SSRF / injection
  • Business logic
recon/Recon scripts

Bash, meant to run inside Kali.

  • subfinder
  • httpx
  • nuclei
reports/ · targets/Report template and per-program scope

One folder per program with the current scope saved before running anything, and a fixed report template.

HackerOne · YesWeHackAutomatic scope + MCPin progress

Pulls each program's current scope into a dated Markdown file and exposes it as an MCP to use with Claude in the SDD workflow.

  • HackerOne API
  • YesWeHack
  • MCP

Certifications & education

  • in progress

    eJPTv2 - Junior Penetration Tester

    INE

    Exam planned for November 2026

  • in progress

    ICCA - INE Certified Cloud Associate

    INE

    In progress, 2026

  • completed

    SOC Fundamentals

    LetsDefend

    2025

  • completed

    Deep Learning

    Centro de e-Learning UTN FRBA

    ID CER-I98GVT0A-1057158

    July 2023

  • degree

    University Programming Technician (Associate Degree)

    Universidad Tecnológica Nacional (UTN)

    Graduated March 2023

  • completed

    Ethical Hacking

    UTN Buenos Aires

    2022

LanguagesSpanish (native) · English (upper intermediate)

How I write code

Almost everything I've built is for companies and can't be shown. MatchHub, a match management app, is what I built to show how I structure an application end to end.

mequerejeta/MatchHub
Presentation · Infrastructure
Application
Domain
Clean ArchitectureDependencies point inward: Domain depends on nothing.
PresentationMatchHub.API
Versioned controllers (api/v1), Swagger and exception-handling middleware.
ApplicationMatchHub.Application
Use cases with CQRS (MediatR), FluentValidation as a pipeline behavior and AutoMapper mappings.
InfrastructureMatchHub.Infrastructure
EF Core with SQL Server, repositories and seed data.
DomainMatchHub.Domain
Business entities and enums, with no external dependencies.

Skills

Application Security
  • OWASP Top 10
  • OWASP API Security Top 10
  • Vulnerability remediation
  • Secure coding
  • SAST (Semgrep)
  • DAST (OWASP ZAP)
  • CI/CD security integration
Penetration Testing
  • Reconnaissance/OSINT
  • Scanning & service enumeration
  • Web exploitation
  • Privilege escalation
  • Password attacks
  • Pivoting
  • Reporting
SOC / Blue Team
  • SIEM (Wazuh)
  • Sysmon
  • Suricata (IDS)
  • Detection rules (Sigma)
  • MITRE ATT&CK
  • Alert analysis
  • Network traffic analysis (Wireshark)
  • Attack and post-exploitation techniques applied to detection
Security Tools
  • Burp Suite
  • Nmap
  • Metasploit Framework
  • Nikto
  • Gobuster
  • WPScan
  • Wfuzz
  • enum4linux
  • smbclient
  • Hydra
  • Hashcat
  • Wireshark
  • Kali Linux
Authentication
  • OAuth 2.0 / OpenID Connect
  • JWT
  • IdentityServer4
Development
  • C#
  • .NET Core
  • Web APIs
  • SQL Server
  • Entity Framework
  • React
  • Next.js
  • Blazor
  • JavaScript
  • Azure
  • IIS
  • Docker
  • Git

Contact

If you're looking for someone for AppSec or a SOC / blue team, email me.

mquerejeta.dev@gmail.com
Emaillinkedin.com/in/mquerejetaGitHub