Ephraim Teodoro

C# · .NET · ASP.NET Core · REST APIs
SQL / MySQL · ADO.NET · MySqlConnector · HttpClient

Professional Role
Enterprise Information Systems Developer
Primary Stack
C# / ASP.NET Core / MySQL
Graduation
B.S. Computer Science, Dec. 2026

Technical Skills

Backend depth, full-stack delivery, research software range.

My strongest professional stack is C#/.NET backend development. I also build web interfaces, database workflows, enterprise integrations, and Python-based research tooling.

Backend

Primary specialization

C# · .NET · ASP.NET Core · REST APIs · async/await · LINQ · Dependency Injection · ADO.NET · MySqlConnector · HttpClient

Languages / Web

Full-stack delivery

React · Next.js · TypeScript · JavaScript · Java · Node.js · D3.js · HTML · CSS

Databases

Data workflows

MySQL · PostgreSQL · Neon PostgreSQL · MongoDB · SQL · SQL Querying · Relational Modeling · Database Transactions

AI / NLP / Research Engineering

Applied research systems

Python · Ollama · spaCy · NLTK · LanguageTool · Local LLM Inference · Human-in-the-Loop Systems · Linguistic Feature Extraction · Rubric-Based LLM Evaluation

Tools / Enterprise

Professional workflows

Git · GitHub · Docker · Postman · Mendix · Workday RaaS · TeamDynamix · Okta · PeopleSoft · Tyk · Visual Studio · VS Code

Professional Experience

2025 - Present

Enterprise Information Systems Developer

Brigham Young University-Hawaii | February 2025 - Present

I build backend services, database workflows, and integrations for enterprise systems used inside the university. My work includes ASP.NET Core APIs, MySQL-backed data flows, third-party service integrations, Mendix applications, internal developer utilities, Docker containerization, and team-based review and release workflows.

Club Management Application

67%

fewer external TeamDynamix API calls

TeamDynamix optimization

TeamDynamix does not have a native club concept. Previously, retrieving tickets for a club required three external API requests. I designed a background synchronization service that stores ticket data in MySQL, enabling one database-backed request instead.

3 external API requests1 database-backed request

Responsibilities

  • Design async ASP.NET Core REST APIs
  • Integrate Workday, Okta, and TeamDynamix with HttpClient
  • Transform enterprise data for internal applications and legacy PeopleSoft workflows
  • Maintain Mendix applications backed by ASP.NET Core services
  • Use SQL transactions with rollback for database workflows
  • Improve validation, exception handling, logging, and backend troubleshooting
  • Build automated alert emails for failed account workflows
  • Create internal developer utilities for formatting server-log data
  • Configure API authorization through Tyk
  • Containerize ASP.NET Core applications with Docker
  • Work through development, acceptance, and main Git branches with pull requests, peer review, acceptance testing, senior review, and production release requests

Technologies Used

C# · .NET / ASP.NET Core · REST APIs · async/await · LINQ · Dependency Injection · ADO.NET · MySqlConnector · SQL / MySQL · HttpClient · Docker · Git / GitHub · Visual Studio · VS Code · Mendix · Workday RaaS · Okta · TeamDynamix · PeopleSoft · Tyk

Earlier Experience

Hope Squad, BYU-Hawaii | August 2024

Designed a website prototype in Figma for stakeholder review and improved program information management using Google Forms, Google Sheets, Google Drive, and QR-code access to digital resources.

Featured Projects

Project work that shows engineering judgment.

These projects are ordered around my strongest current signal: research engineering, full-stack product work, enterprise backend development, and data visualization research.

Local HITL pipeline

Electron desktop frontend
Local HTTP API
Python backend
Linguistic analysis + local LLM inference
Human reviewer
Final score / notes / workbook export
01

Project 01 / Research Engineering

HITL Multi-Evidence ESL Essay Assessment System

A local desktop research system for ESL essay assessment that combines linguistic feature extraction, local LLM rubric evaluation, and human review.

Python · Electron · Ollama · spaCy · NLTK · LanguageTool · Local LLM Inference

Problem

The research needed more than prompt experiments: it needed a working system that could process essays, preserve evidence, support human decision notes, and export completed workbook results.

Solution

I built the technical system around an Electron desktop frontend, a local HTTP API, and a Python backend that coordinates NLP tools, local LLM inference, scoring progress, review screens, and workbook export.

My Role

Primary technical system builder for the research framework, translating the study requirements into a local/offline application workflow.

Result

Implemented and ready for experimental use. Associated research accepted for presentation at the 23rd AsiaCALL International Conference in Hanoi, Vietnam, November 14-15, 2026.

Architecture / Technical Highlights

  • Electron desktop frontend with local API communication
  • Python backend integrating spaCy, NLTK, LanguageTool, Ollama, and local Llama inference
  • Multi-evidence comparison between linguistic features and model judgments
  • Human reviewer workflow for final scores and decision notes
  • Local-only processing so essays, model inference, reviewer decisions, and outputs remain on the local machine

Rule-based practice flow

01Learner Activity
02Performance Statistics
03Due / Weak / New Classification
04Rule-Based Scoring
05Recommended Practice
02

Project 02 / Full-Stack Learning Platform

Learn-Kana

A Japanese-learning platform for Hiragana, Katakana, and 2,140 Joyo Kanji with flashcards, quizzes, progress tracking, and rule-based adaptive practice.

Next.js 14 · TypeScript · MongoDB · Google Login · localStorage

Problem

Learners need targeted practice that responds to weak characters, due reviews, recent mistakes, and confusion pairs without relying on a one-size-fits-all lesson order.

Solution

I built a Next.js 14 and TypeScript application with localStorage persistence for anonymous users, MongoDB persistence for authenticated users, and Google federated login.

My Role

Full-stack developer for the learning interface, persistence model, learner analytics, and rule-based recommendation workflow.

Result

Implemented as a rule-based adaptive learning system with deterministic recommendations, not machine learning or generative AI.

Architecture / Technical Highlights

  • Adaptive practice based on spaced repetition, accuracy, response time, recency, incorrect-answer history, and confusion pairs
  • Priority order of due reviews, weak characters, then new material
  • Learner dashboard with weak kana, character statistics, attempts, response times, confusion-pair detection, and recommendations
  • Anonymous localStorage state and authenticated MongoDB-backed progress

TeamDynamix retrieval

3

external TeamDynamix API requests

1

database-backed request

67%

fewer external API calls

03

Project 03 / Enterprise Backend

Club Management / Enterprise System

A professional ASP.NET Core system that connects club workflows with TeamDynamix and MySQL-backed ticket retrieval.

C# · ASP.NET Core · MySQL · ADO.NET · REST APIs · TeamDynamix · Docker

Problem

TeamDynamix does not have a native club concept, so retrieving tickets for a club previously required three external TeamDynamix API requests.

Solution

I designed a background synchronization service that stores TeamDynamix ticket data in MySQL, allowing the application to retrieve a club's tickets through one database-backed request.

My Role

Lead developer and project manager, coordinating development with the team and Student Leadership Services while contributing backend APIs, integrations, and database workflows.

Result

3 external TeamDynamix API requests -> 1 database-backed request, a 67% reduction in external API calls.

Availability

Internal workplace application with proprietary code and no public demo or repository. For department inquiries, visitors can contact BYUH Enterprise Information Systems.

Architecture / Technical Highlights

  • Asynchronous ASP.NET Core REST APIs
  • HttpClient integrations with enterprise systems including TeamDynamix, Workday, and Okta
  • SQL transactions with rollback, validation, exception handling, and logging improvements
  • Tyk authorization configuration, Docker containerization, pull requests, acceptance testing, senior review, and production release requests

Visualization study

30

participants

2

chart designs

Pattern

and outlier tasks

ScatterBubble
HighLow

Outlier cluster

ArrivalsSpend
04

Project 04 / Data Visualization Research

Tourism Data Visualization Research

A research project comparing how visualization design affects pattern and outlier identification in tourism data.

D3.js · Neon PostgreSQL · Experimental Design · Statistical Analysis

Problem

The study investigated how standard and bubble scatter plots affected pattern recognition, population comparison, and outlier detection using United Nations tourism data.

Solution

I combined D3.js visualization work, Neon PostgreSQL-backed data handling, experimental design, and statistical analysis in a 30-participant counterbalanced within-subjects study.

My Role

Research software contributor working across visualization implementation, experiment design, data handling, and analysis.

Result

Found that bubble scatter plots improved pattern recognition and population comparison, while standard scatter plots performed better for outlier detection.

Architecture / Technical Highlights

  • Interactive D3.js scatter plot and bubble scatter plot research interface
  • 30-participant within-subjects experiment with counterbalancing
  • Collected task-accuracy and Likert-scale data
  • Shapiro-Wilk and Wilcoxon signed-rank analysis
  • Presented at the BYU-Hawaii Undergraduate Research Conference on April 2, 2026

Earlier work, including a system health dashboard and a simple university demo API, is intentionally de-emphasized here so the homepage focuses on stronger current professional and research work.

Research

Applied research with working software behind it.

My research work connects software engineering with experimentation, language learning, visualization, and human-centered evaluation.

2026

Beyond Prompt Engineering: A Human-in-the-Loop (HITL) Multi-Evidence Framework for ESL Essay Assessment

23rd AsiaCALL International Conference

Hanoi, Vietnam, November 14-15, 2026

Accepted for presentation

2026

The Impact of Visualization Design on Identifying Patterns and Outliers in Tourism Data

BYU-Hawaii Undergraduate Research Conference

Laie, Hawaii, April 2, 2026

Presented

About

I like reliable software that solves real operational and research problems.

I am a Computer Science student at Brigham Young University-Hawaii and an Enterprise Information Systems Developer at BYU-Hawaii. My professional work centers on C#/.NET backend development, enterprise integrations, REST APIs, database workflows, and full-stack internal systems.

Alongside that enterprise work, I build research software with Python, NLP tools, local LLM inference, and human-in-the-loop workflows. I am especially interested in software that makes complex operations clearer, faster, and easier to trust.

Education

Brigham Young University-Hawaii

  • B.S. Computer Science, expected December 2026
  • Minor in Visual Arts
  • TESOL Certificate

Honors / Leadership

  • Upsilon Pi Epsilon
  • Dean's List
  • President, Computer Science Club - Spring 2025

Contact

Let's talk about software engineering roles.

I am interested in junior software developer, software engineer, C#/.NET developer, backend developer, full-stack developer, and research software roles.

Emailephraimteodoro@gmail.comGitHubgithub.com/EPHRAIMTEODOROLinkedInlinkedin.com/in/teodoro-ePortfolioephraimteodoro.comResumeDownload Ephraim_Teodoro.pdf