Cloud & Microsoft 365
- Microsoft 365 Admin
- Exchange Online
- SharePoint
- Teams
- Entra ID / Azure AD
- Cloud Migration
- AWS S3 / Lambda
- Cloudflare Workers
Houston, TX · Infrastructure · Security · Automation
Jonathan Castro
IT Systems Architect & Cybersecurity Engineer
I design, secure, and automate the entire technology stack of a growing company — cloud, telephony, security, and the apps that hold it all together.
- 0Years owning the stack
- 0Projects shipped
- 0Cloud migrated
- M.S.Cybersecurity
01 — About
The one-person IT department.
I'm Jonathan — the entire technology department for a Houston-based financial services company. For nine years I've owned every layer of the stack: the network, the servers, Microsoft 365, the phone system, the CRM, security, and the help desk.
Since 2024 I've run all of it solo. When something doesn't exist yet, I build it — cloud migrations, call-routing logic inside the dialer, AI voice agents that qualify inbound calls, internal web and desktop apps, and the automations that keep everything talking to each other.
I hold a B.S. in Cybersecurity and am completing a Master of Science in Cybersecurity (GPA 3.73) — all while raising my daughter full-time. I like hard problems, clean systems, and shipping things that actually work.
02 — Skills
A deep, hands-on toolkit.
Built over nine years of being the person everything lands on.
Cybersecurity
- Penetration Testing
- PTES
- Incident Response
- MFA & RBAC
- Firewall / VPN
- Vulnerability Scanning
- IDS / IPS
- Forensics
- NIST CSF 2.0
- CMMC / 800-171
Automation & Integration
- Power Automate
- Microsoft Graph API
- Zapier
- Webhooks & REST APIs
- GoHighLevel
- SuiteCRM
- Office Scripts
- Workflow Design
Networking & Telephony
- Network Administration
- Network Security
- DNS Management
- Nginx / Reverse Proxy
- ViciDial
- Asterisk AGI
- SIP Trunking
- Twilio
- Retell AI
Servers & Systems
- Windows Server
- Debian Linux
- Kali / WSL2
- Dell PowerEdge
- MariaDB / MySQL
- Backup & Recovery
- Fail2Ban / UFW
- Suricata
Development & Scripting
- Python
- PowerShell
- PHP / Laravel
- Node / Express
- Next.js / React
- HTML / CSS / JS
- Electron
- SQL
- WordPress
03 — What I Build
If it doesn't exist, I build it.
Cloud & Infrastructure Migration
Moving entire companies off on-prem and into the cloud — phone systems, CRMs, file storage, and every user — with zero downtime.
Cybersecurity & Network Defense
Penetration tests, incident response, hardened Linux servers, intrusion detection, honeypots, and dashboards that watch the network in real time.
Telephony & Call-Flow Engineering
Inbound call routing inside the dialer — state-based queues, custom AGI logic, SIP trunks, and vendor integrations that get callers to the right agent fast.
AI Voice & Chat Agents
Voice AI that answers, pre-qualifies, and transfers live calls — plus the platform migrations and cost models that decide which vendor runs it.
Automation & Systems Integration
Power Automate + Graph API flows, cloud archiving pipelines, Zapier and webhook integrations that wipe out repetitive manual work.
Custom Apps & Portals
Laravel and Node web apps, Electron desktop tools, and internal portals that solve problems no off-the-shelf product does.
Data Analysis & Dashboards
Turning messy call-center and sales data into clean reports, funnel diagnostics, and interactive dashboards that drive decisions.
Web Development & Design
Fast, modern, responsive sites — from WordPress business builds to hand-coded portfolios and Next.js applications.
04 — Featured Projects
Six things I'm proud of.
Real work, described at a high level — no client data, company names, or internal numbers shown.
SecurityClient engagement
External Penetration Test — Museum Firewall
Authorized external penetration test of a Houston art museum's dual-WAN Meraki MX95 firewall. Scoped, documented, and executed under a signed rules-of-engagement and authorization letter, then delivered as an actionable remediation report to the client's Director of IT.
- Drafted the ROE and authorization letter; scoped both WAN interfaces, excluded web and social engineering
- PTES-aligned recon, port and service enumeration, and vulnerability analysis from a Kali attacker box
- Findings mapped to severity with clear remediation steps for a non-security IT team
- Kali Linux
- nmap
- PTES
- Meraki MX
- Report writing
AITelephony
Voice AI Platform Build & Migration
Designed and shipped an AI voice layer that answers inbound vendor calls, pre-qualifies the caller, and hands them to a licensed agent — one agent per vendor line. Then diagnosed a platform-level billing defect where the AI leg kept metering after handoff, built the business case, and re-architected the whole voice layer onto a new provider.
- Proved the original platform over-billed transcription many times over across a full month of call data
- New path: SIP trunk → AI agent → cold transfer that preserves the caller's number so downstream state routing keeps working
- Recordings and transcripts offloaded to S3 through a Lambda bridge; projected spend cut by more than half
- Retell AI
- GoHighLevel
- SIP / Voxtelesys
- Cloudflare Workers
- AWS Lambda + S3
- ViciDial API
TelephonyData
ViciDial Call-Routing Engineering
A body of work on a hosted ViciDial dialer: audited and mapped the full inbound flow (router → silent IVR → area-code lookup → per-state queues → overflow), then engineered targeted changes to fix real business problems.
- Custom Asterisk AGI in-group tiering so a high-value vendor's calls reach preferred agents first and overflow only when needed
- 30-day funnel diagnostic that uncovered a race condition between vendor pings and AI pre-qualification time
- New vendor live-transfer integration with a decoupled data path to eliminate screen-pop lag; campaign analytics dashboards
- ViciDial
- Asterisk AGI
- MySQL
- Python
- Power Automate
- Ringba API
AppsAutomation
Agent Contracting Portal
A Laravel web portal that replaces a paper-and-email onboarding process. Admins manage a library of multi-carrier fillable PDF contracts, assign them to new agents, and control field-by-field who can edit what. Agents fill, sign, upload supporting docs, and submit.
- Server-side authoritative fill and flatten on finalize — the browser never produces the legal copy
- Drawn signatures and initials, drag-and-drop upload slots, and per-field agent/admin permissions
- Finalized PDFs land automatically in each agent's SharePoint folder via Graph API
- Laravel 11
- MySQL
- Node sidecar
- pdf.js
- Microsoft Graph
- Cloudways
AppsData
Underwriting & Quote Engine
Digitized every carrier underwriting guide into a rules engine. An agent enters a client's demographics, conditions, and medications and gets back the carriers they qualify for, the policy tier, a quote, and carrier-specific underwriting notes — in seconds instead of flipping through spreadsheets.
- Thousands of conditions and medications with knockout rules, timing windows, and tiered results (Preferred / Standard / Graded / ROP)
- Full admin panel: carrier, condition, and medication CRUD plus bulk CSV import; per-agent carrier visibility
- Ported to an Electron desktop app with a local SQLite database for offline use
- PHP
- MySQL
- JavaScript
- Electron
- SQLite
- Python data pipeline
WebAutomation
Public Rate-Quote Form
Replaced a broken, decade-old quote form on the company website with a fast, hand-built quoter that returns real carrier pricing from age, tobacco status, state, and coverage amount — and feeds every lead straight into the dialer and a tracking sheet.
- Carrier rate spreadsheets converted to JSON with a Python extractor so pricing updates without touching code
- Solved a wave of bot-generated blank submissions by moving webhook calls behind a server-side proxy
- Zapier pipeline routes each submission to the dialer and a shared sheet in real time
- HTML / CSS / JS
- PHP proxy
- JSON rate data
- Python
- Zapier
- WordPress
WebMigration
Financial Services Company Website
Ground-up rebuild of a financial services company's public site — replacing a decade-old, plugin-choked WordPress install with a clean WordPress + Elementor build on managed cloud hosting behind Cloudflare. Owned it end to end: server provisioning, page builds, a 311-post blog migration, and the go-live strategy.
- Provisioned and tuned the hosting stack (PHP 8.4, MariaDB, Redis) on a staging server, then planned go-live as a fresh install on the production box instead of a risky DNS cutover
- Hand-built homepage, About, Team, and Reviews sections as custom HTML embeds; solved the "Posts page" problem with a Theme Builder archive template, category sidebar, and pagination
- Migrated 311 posts through three scripted XML cleaning passes — purged 33 MB of legacy page-builder metadata, 150+ dead CTA banners, proxy-wrapped links, and duplicates — then bulk-categorized via API and restored 250 featured images
- Audited every post for stale content: 527 broken links, industry pricing stats re-verified against the source, and a tiered week-by-week update playbook
- WordPress
- Elementor Pro
- Cloudways
- Cloudflare
- Python
- WP REST API
- PHP 8.4
- MariaDB
SecurityForensics
Legacy Hosting Forensics & Decommission
A single fatal-error email led to an orphaned WordPress server on legacy shared hosting that nobody knew was still running — on PHP unpatched since 2018 and publicly reachable. Ran the full investigation from external recon through evidence-preserving containment, and wrote the decision memo management used to safely shut it down.
- Email-header forensics, DNS sweeps, and host-header reachability tests to identify the box and prove which hostnames could actually reach it
- Found an unauthenticated admin-creation script that had silently created a rogue administrator account 7.5 years earlier — plus two other external admin accounts nobody had rotated
- Scoped 175 customer form records via SQL against state breach-notification and insurance data-security statutes; confirmed no SSN, DOB, financial, or health data present
- Baselined a 40-record DNS zone that turned out to be load-bearing for 12 live services, inventoried five separate SSL line items (one silently protecting the CRM), and flagged $899 of prepaid hosting for a dead server
- Incident response
- DNS forensics
- SQL
- WordPress internals
- PowerShell
- Breach-notification law
- Decision memos
Security
Network Security Monitor
Self-hosted Flask dashboard with Suricata IDS, a honeypot, auto-banning via Fail2Ban + UFW, nmap device discovery, and a clickable live threat map.
Security
Debian Server Hardening Suite
End-to-end lockdown of Debian 13 servers — SSH hardening, firewall rules, log parsing, automated HTML reports, and a public status dashboard.
Security
Incident Response Investigation
Led a suspected-data-exposure investigation across M365, identity, CRM, and SaaS systems: playbook, evidence log, cluster analysis, containment, and findings mapped to breach-notification law.
Security
Security Alerts Dashboard
Power Automate flows that parse phishing-report PDFs and Microsoft 365 alert emails into SharePoint lists with a single sortable dashboard.
Automation
SharePoint → S3 Storage Offload
Migration tooling and a nightly reconciled ledger that moves cold data and call logs from SharePoint to AWS S3 — thousands of rows a day with zero pipeline losses.
Automation
Zoom Cloud Archive & Retention
Server-to-Server OAuth exporter that inventoried and bulk-archived years of cloud recordings to S3, then enforced a retention policy so storage never overflows again.
Automation
Call Recordings → SharePoint
Multi-phase Power Automate + Graph API pipeline that pulls AI call recordings and transcripts from the voice platform into SharePoint, then cleans up at the source.
Automation
Teams Tech-Issue Extractor
Python + Graph API script that mined every Teams channel for reported tech issues, plus a nightly flow that keeps a searchable SharePoint tracker current.
Automation
Daily Sales Report to Teams
Email-triggered Power Automate flow that hands the raw report to an Excel Office Script, rebuilds it as a clean table, and posts it to the sales team's Teams channel every night — no one touches a spreadsheet.
Automation
CRM & SMS Workflow Automation
Zapier and Twilio automations for client welcome letters and SMS notifications, plus reverse-engineered and repaired Power Automate reporting flows.
AI
AI Sales-Training Simulator
A voice AI that plays the customer — random personas, randomized difficulty, realistic-but-fake details — so agents can drill objections and closes on demand.
AI
Deterministic Underwriting Chat
A rules engine wearing a chat interface — not generative — that walks a lead through health questions and returns the three best carrier quotes they actually qualify for.
AI
Desktop AI Companion
Electron desktop assistant with an animated avatar, voice in/out, screen vision, agentic actions, and persistent memory — built on the Claude API.
AI
Custom AI Skills & Tooling
Authored reusable AI workflow skills — interruption-resilient project memory, a full website scaffolder with a design search engine, and a call-flow analyzer.
AI
Automated Short-Video Pipeline
Python pipeline that scripts, renders, and schedules daily IT tips with animated backgrounds and karaoke-style captions synced to recorded voice.
Apps
IT Help-Desk Bot
Decision-tree support bot embedded as a Teams tab — zero AI cost — that walks staff through fixes and escalates the full transcript to IT when it can't.
Apps
IT Project Tracker
Standalone Node/Express app with JSON storage and JWT admin/worker roles that tracks projects, tasks, notes, and activity — plus a Cloudflare email worker.
Apps
Guild Management Web App
Next.js 16 + Prisma + MariaDB app for a gaming community: inventory, crafting library, rank-based permissions, tasks, and a threaded message board with @mentions. Public over HTTPS.
Apps
Self-Hosted CMS & Page Builder
A WordPress-admin-meets-Elementor platform: drag-and-drop visual editor, responsive controls, form and popup builders, plugin architecture, and a one-click installer.
Apps
Study & Education App
Self-hosted study app with a rewards tracker, curriculum-aligned lessons, and an admin back-end — shipped with user and setup manuals.
Apps
Self-Hosted CRM & Finance Dashboard
SuiteCRM deployed on a hardened home server behind Nginx, plus a Plaid-connected personal finance dashboard (Flask + React + SQLite).
Data
Call-Center Conversion Analytics
Pulled and analyzed a month of dialer data — agent and vendor performance, funnels, capacity math — and delivered written findings to ownership.
Data
Vendor Cost Modeling
Reconciled eight months of platform invoices to within one percent and built the side-by-side cost model that justified a voice-AI vendor switch.
Data
Ops Alerts Dashboard
Single-pane dashboard pulling security and error signals from nine SaaS and infrastructure sources. Flask on Debian behind nginx + Let's Encrypt, gated by Cloudflare Zero Trust with the origin locked to Cloudflare IPs only.
Web
Client & Creative Web Builds
A local mechanical-bull rental business site with a DevTools shield, an actor portfolio (Astro), an author site, anime-themed art sites, and this portfolio.
05 — Education
Sharpening the edge.
Master of Science in Cybersecurity
CompletingCoursework: Risk Management, Information Security Governance, Incident Response Planning, NIST CSF 2.0, CMMC / NIST 800-171 Compliance, Cyberterrorism, and Healthcare Cybersecurity.
Bachelor of Science in Cybersecurity
CompletedFoundations in security architecture, networking, systems administration, and risk — the groundwork behind everything on this page.
06 — Contact
Let's build something.
Got a project, a role, or a problem that needs solving? Reach out directly.
Email me