Security Architect & Systems Engineer

Architect | Builder | Breaker

I started out as a full-stack engineer and gradually moved deeper into security. Over time, I’ve learned that security has to be part of how systems are designed from the start.

My work sits at the intersection of building and breaking. I think like a developer when creating systems, but I also approach them with an attacker’s mindset to understand how they might fail.

I focus on network protocols and system internals, using that perspective to design layered, resilient systems that hold up in real-world conditions. My goal is simple: build software that works but also stays secure under pressure.

bash — root@sentinyl:~ (zsh)
$ whoami
Mark M. Munyiri Role: Security Architect & Systems Engineer Mission: Building hardened, production-ready systems Focus: DevSecOps | Container Security | Systems Programming | Threat Intelligence
$ ls projects/
sentinyl-enterprise/ rust-traffic-inspector/ capture-v2/ arsenal.txt
$ cat arsenal.txt
Python React/TypeScript FastAPI Docker PostgreSQL Neo4j Redis ... and many more
root@sentinyl:~#

EXPERIENCE & TRAINING

ZETECH UNIVERSITY

Diploma in Software Engineering | 2024 - 2026

Foundation in software architecture, full-stack development, and SDLC. Learned to build production systems, not just write code. Major project: Verba real-time audio transcription platform with WebSocket streaming achieving sub-100ms latency.

React Node.js WebSockets Full Stack SDLC
>> LEARNED: Software architecture, async data flow, real-time systems

CYBERSHUJAA

Security Analyst | Sep - Dec 2025

Transitioned from building systems to breaking them. Conducted active network exploitation: ARP spoofing, Man-in-the-Middle attacks, deep packet inspection with tcpdump. Moved from passive scanning to offensive operations, learning that you can't secure what you don't understand at the protocol level.

ettercap tcpdump Wireshark ARP Spoofing Network Forensics
>> LEARNED: Offensive security, how systems break, red team thinking

MORINGA SCHOOL

AI Practitioner Certification | Oct 2025

Intensive one-month specialization in Machine Learning pipelines and Data Engineering. Learned to treat security as a data problem: apply ML to threat detection, use predictive models for risk analysis, build automated classification systems. Not about using ChatGPT—about understanding the math and pipelines behind intelligent systems.

Machine Learning Data Pipelines MLOps Predictive Analytics
>> LEARNED: ML pipelines, data engineering, automated threat classification

PROJECTS

CAPTURE

Forensic-Grade Screenshot Tool

Local-first desktop application engineered for security professionals. Features granular image quality adjustments, automatic PII redaction (API keys, IPs) via regex/OCR, and strict chain-of-custody tracking.

Python Executable PyQt6 Tesseract OCR SQLite
✓ Zero Cloud Dependencies
✓ Local PII Sanitization
>> STATUS: RELEASED (v2.0)

SENTINYL ENTERPRISE

Zero-Liability Digital Risk Protection SaaS

Architected enterprise-grade microservices platform with defense-in-depth security achieving 75% attack surface reduction. Built Neo4j-powered graph database to map complex threat relationships, risk scoring engine with MITRE ATT&CK integration, and Stripe-based usage billing with automatic quota enforcement.

Python (FastAPI) Neo4j Docker PostgreSQL Redis Stripe
✓ Network Isolation (CIS/NIST Compliant)
✓ Read-Only Containers
✓ MITRE ATT&CK Mapping
>> STATUS: IN DEVELOPMENT

RUST AD BLOCKER

User-Space Network Ad Filter

Built a real-time ad blocker from scratch in Rust without using any external libraries. Bypassed kernel/root requirements by engineering a Layer 7 proxy that intercepts HTTP traffic in user space. Manually captures raw TCP streams, parses HTTP requests, detects ad signatures (like "banner", "ad", "tracker"), and injects instant 403 Forbidden responses to block ads before they load.

Rust TCP/IP HTTP Parsing Ad Blocking std::net
✓ Zero Dependencies
✓ Real-Time Ad Detection
✓ No Root Access Required
>> STATUS: OPEN SOURCE

ARSENAL

CORE COMPETENCIES

Python (Advanced)
React / TypeScript
FastAPI
Docker (Hardening)
PostgreSQL
Neo4j (Graph DB)
Redis
Linux SysAdmin
DevSecOps
Git / CI/CD
Container Security
MITRE ATT&CK
Network Protocols
ARP Spoofing
MitM Attacks
Network Forensics
Penetration Testing
Rust (Systems)
Bash Scripting
Digital Forensics
Windows Internals
Forensic-Grade Imaging
Memory Forensics
Artifact Analysis
Static & Dynamic Malware Analysis