Johann Valenteros

„Weniger, aber besser.“

— Dieter Rams

Cybersecurity & information systems. I build small, simple tools and contribute to open source.


About

Undergraduate student at the University of Missouri–St. Louis.

I work mostly in the open: small security utilities, encryption tools, and the occasional web build. I care about simple, easy-to-read code, careful detail, and learning by making mistakes.

Selected works

jvblog — Astro · Blog (featured)

A minimalist, experimental personal blog built with Astro. Posts and worldbuilding lore are written as plain Markdown and stitched together Obsidian-style with [[wiki-links]].

  • Built with Astro, content authored as Markdown in an Obsidian vault
  • Obsidian-style [[wiki-links]] connect posts, characters, and lore
  • Broken-link checking wired into the production build

Astro, Markdown, Obsidian, JavaScript

Read the blog · Repository

Encryption App — Python · 2024

A Python application for encrypting and decrypting files using industry-standard cryptographic algorithms. A study in cryptographic principles and secure programming.

  • Multiple algorithms (AES, RSA) with secure key generation
  • File integrity verification via checksums
  • Clean CLI and detailed logging / error handling

Python, Cryptography, Security

Repository

Ciphers — React · Web

A web app for encoding and decoding text across classic ciphers. Originally built with vanilla JS and Tailwind, later rebuilt with React + Vite for a modular, modern stack.

  • ROT13, Caesar, Vigenère
  • Atbash, Rail Fence, Beaufort
  • Real-time character & word count

React, Vite, Tailwind, JavaScript

Repository · with M. Rodriguez

Password Strength Checker — Bash · CLI

A command-line tool that scores password strength against length, character variety, and common patterns. In collaboration with Michael Rodriguez and grounded in basic security principles.

  • Checks length and use of upper / lower / number / symbol
  • Returns a strength score and recommendation
  • Follows safe password-handling practices

Bash, Security, Command-line

Repository · with M. Rodriguez

Password Generator — Web · 2024

A browser-based generator for strong, random passwords. Everything runs client-side; passwords are never sent over the network.

  • Adjustable length (8–128) and character sets
  • Strength indicator and one-click copy
  • Uses the Web Crypto API for secure randomness

HTML, CSS, JavaScript

Repository

This website — HTML · 2026

One HTML file. No CSS, no JavaScript, no web fonts, no build step. The browser already knows how to render a document, so I let it. Main inspiration: motherfuckingwebsite.com.

  • Semantic HTML only; expandable entries use <details>
  • Light and dark mode come from the browser via color-scheme
  • Fast, accessible, readable in any browser, including text-only ones

HTML

Repository

Skills

Development
HTML & CSS, JavaScript, Python, Java, Node.js, Bash, C#, Git, GitHub, GitLab
Design
UI / UX, Tailwind CSS, Typography, Photoshop, Illustrator

AI workflow

Utilizing an AI-assisted workflow, hand-verified. I stay accountable for every line.

It's no surprise that AI has dominated most front and backend roles. I use AI-assisted development to ship clean, responsive websites while keeping the design authorship, debugging, manual deployment, and quality control in my own agency. I scrutinize and peruse every change by hand, trace and fix errors myself, inspect the console, and test edge cases, and I can explain in depth every component, every choice, and the reasoning behind each one.

AI tools
Claude Code, Codex, VS Code with a Claude Fable workflow, JetBrains Suite
Backend & data
RDBMS, PostgreSQL, SQL, MySQL, Insomnia API

Experience

Healthcare Simulation & Information Systems Assistant

University of Missouri–St. Louis · Part-time · St. Louis, Missouri · On-site
Jan 2026 — Present

Hands-on systems work across the university's healthcare simulation center: AV capture, networked patient simulators, rack servers, and the cabling that ties the building together.

Details

Our nursing simulation center is basically a small production environment: capture servers, networked manikins, wireless control links, and cable runs spanning the building. I approach it the way a defender approaches any environment: inventory every asset, document every path, assume failure before it happens.

Systems & access

  • Administered Panopto AV capture across simulation suites, with roles, permissions, and recording access scoped so sensitive training sessions stay with the people cleared to see them
  • Operated Laerdal and Gaumard high-fidelity simulators end to end, from software interfaces to physical hardware, managed like embedded devices: firmware current, wireless links accounted for, unusual behaviors documented and baselined

Electrical soldering & simulator hardware

  • Performed practical electrical soldering work involving battery leads, wiring connections, small components, and hardware repairs, with attention to clean joints, secure connections, polarity, insulation, and safe handling
  • Assisted with manikin installations and simulator hardware setup, connecting internal electronics, cables, sensors, power systems, and peripheral components while troubleshooting physical hardware issues as they came up
  • Applied hands-on electrical troubleshooting skills across simulator and training equipment, including checking connections, identifying loose wiring, documenting unusual hardware behavior, and supporting reliable day-to-day operation

Infrastructure & physical layer

  • Racked, cabled, and serviced rack servers and AV infrastructure
  • Traced and verified wiring across separate buildings with toner-and-probe kits and cable sniffers, confirming every drop terminates and mapping the runs that were never written down
  • Practical electrical systems work: documenting, illustrating, and isolating faults

Documentation & troubleshooting

  • Wrote troubleshooting documentation, from manikin SOPs to software quickstarts and recovery guides

Panopto, Laerdal, Gaumard, Rack Servers, Cable Tracing, Electrical Systems, SOPs & Runbooks, Troubleshooting

Education

B.S. Cybersecurity — Information Systems & Technology
University of Missouri–St. Louis · Expected 2027
Transferred Fall 2025
A.A.S. Cybersecurity
St. Louis Community College · 2025
GPA 3.75 · Cum Laude

Certifications

Contact

Open to opportunities and good conversations.

connisquer@gmail.com
GitHub · LinkedIn · X · Bandcamp