Full-stack engineer · Houston, TX
jonathansaulcontreras@gmail.comgithub.com/JonathanSContreraslinkedin.com/in/jonathanscontrerasjonathancontreras.com
Full-stack engineer building public-facing software where correctness matters — crime-data tools for Houston, a production job-search platform, and local-first developer tooling. I constrain AI features toward honesty over polish: deterministic scoring instead of model-guessed numbers, quotas that fail closed, and a written account of where that constraint is still missing.
Crime Stoppers of Houston · Glenda Gordy Research Center
Building and maintaining full-stack applications and internal dashboards in React, Next.js, TypeScript, Node and PostgreSQL, deployed on AWS Amplify with Cognito-backed auth. Primary technical contact from scoping through deployment, translating operational needs from non-technical program staff into working tools.
Jun 2026 —
Enoch Studio
Web development, branding, print and AV production for church and nonprofit clients across Houston. I own each engagement end to end — discovery, scoping, build, launch, support. Most recently a full bilingual site for Casa de Dios with a content model their staff runs without a developer.
Mar 2026 —
Self-employed
One-on-one tutoring in AP Computer Science A and Principles, plus data structures and interview prep. Students have passed their AP exams, strengthened their fundamentals, and landed internships.
Feb 2025 —
Houston Christian University
Supported instruction across Operating Systems, Advanced Data Structures & Algorithms, Computer Networks and Software Engineering. Weekly office hours mentoring 25+ students on thread management, deadlock resolution, TCP/IP stack behavior and OOP design. Contributed to rubrics and course materials under ABET accreditation standards.
Aug 2023 — May 2026
Harmony Public Schools
Supported middle school students exploring foundational computer science through hands-on instruction, reinforcing lesson material and helping students build problem-solving skills from the ground up.
Aug 2022 — May 2026
Glenda Gordy Research Center
Built and launched the public At-A-Glance Statistics page. Designed secure API routes and a hybrid ingestion pipeline to fetch, aggregate and cache data from internal systems and vetted public feeds — low-latency updates without exposing sensitive records.
May — Aug 2025
The Data Mine · Purdue — Houston Fire Dept.
Built Python data-cleaning and visualization tools that improved the Houston Fire Department’s response-time analysis, then used those insights to design strategies for resource allocation and emergency response efficiency.
Aug 2024 — May 2025
Bible Study Fellowship
Helped restructure the organization’s website, migrating to WordPress and implementing open-source solutions to improve usability, scalability and cost. Collaborated on web architecture and modernized hosting and integration infrastructure.
May — Sep 2024
The Data Mine · Purdue — with V2X
Developed an LLM-powered chatbot answering aviation questions from specialized documentation. Trained and tuned the model with NLP techniques using R, SQL and Python. My first real exposure to where models are and are not trustworthy.
Aug 2023 — May 2024
University of Oklahoma
Pursuing a Master of Science in Applied Computing remotely from Norman, alongside full-time engineering work.
Aug 2026 — Jul 2027 (expected)
Houston Christian University
Graduated Cum Laude with a 3.67 GPA. Upper-division coursework in Operating Systems, Computer Networks, Advanced Data Structures & Algorithms and Software Engineering. TA across four courses, and spearheaded Raspberry Pi integration into the Computer Architecture lab curriculum.
Aug 2022 — May 2026
A LaTeX résumé builder wrapped in a full job-search toolkit. Every tracked application links back to the exact résumé version you sent. Metered AI runs on atomic, fail-closed quotas that auto-refund a failed provider call.
Next.js · React · JavaScript · Tailwind CSS · Supabase · Stripe · OpenRouter · LaTeX · PostHog · Sentry · Vercel
100+ Resumes generated
A native iOS networking-memory app, solo from empty repo to the App Store in 23 days. Contacts are indexed by event rather than alphabetically, everything lives in on-device SQLite, and the app makes no network requests at all — the intake flow round-trips through QR codes instead of a server.
React Native · Expo · Expo Router · TypeScript · SQLite · Drizzle ORM · Zustand · ML Kit · expo-notifications · Jest · EAS Build
23 Days solo to the App Store
The public crime-data dashboard for the Glenda Gordy Research Center. Two government sources with conflicting counts, reconciled nightly into pre-computed aggregates — with a staleness indicator instead of a quietly wrong number.
Next.js · Tailwind CSS · JavaScript · Python · SQL
2 Sources reconciled
An LLM agent graph drives nmap adaptively, then a deterministic layer takes over: a flag sanitizer decides what is allowed to run, and an XGBoost regressor — not the model — produces the score the remediation queue sorts by.
Next.js · React · TypeScript · Tailwind CSS · d3-force · FastAPI · Python · LangGraph · XGBoost · Ollama · SQLite · Nmap
8 Agents in the graph