Backend · AI/ML · Cloud

ROJEAN PEÑANO

Software Engineer — Backend & Intelligent Systems

I don't just write code. I engineer systems.

About

I build systems where machine learning leaves the notebook and meets real users. My thesis project, Rice Up, put CNN-based crop disease detection and price forecasting in the hands of Filipino rice farmers — and taught me that the hard part of AI isn't the model, it's the engineering around it.

My foundation is backend architecture: Python services, REST APIs, cloud deployment on Azure and Firebase. I care about modular design, clean interfaces, and code that the next engineer can read without asking me what it does.

I'd rather solve a problem with a simple system that works than an impressive one that doesn't.

location
Tagaytay City, Cavite, Philippines
degree
Bachelor of Science in Computer Science at De La Salle University - Dasmariñas
focus
Backend · AI/ML · Cloud
status
Open to opportunities

Projects

Flagship · Undergraduate Thesis · 3-person team · 2025–2026

Rice Up

A Web Application for Rice Leaf Disease Detection Using CNN and Farming Support for Filipino Palay Farmers in Naic, Cavite.

Rice diseases are cheapest to fight when caught early — but palay farmers in Naic diagnose by eye and memory, with occasional technician visits. Existing agri-apps go unused because they assume connectivity, devices, and digital literacy rural farmers don't have. Rice Up puts a disease diagnosis in a farmer's pocket: photograph a rice leaf, get a classification — entirely in Filipino, designed with the farmers and the Municipal Agriculturist of Naic.

System architecture

MOBILE WEB CLIENTHTML · CSS · JS — Filipino UIREST · JSONisolated inference — on-demand cloud runtimeDISEASE APIFlask · VGG169-class classifierPEST APIFlask · CNNbinary classifierPRICE APINode.js · regressionBantay Presyo CSVFIREBASEAuth · Firestorecalendar · user data

Core feature — disease detection

The heart of Rice Up is a VGG16 transfer-learning classifier trained on 10,689 rice leaf images across nine disease categories, referenced against the DA–PhilRice field guide to keep every diagnosis aligned with officially recognized agronomy. VGG16 was selected after head-to-head evaluation against ResNet50 and EfficientNetB4 — it converged most reliably and produced the most stable validation scores under our compute constraints.

A farmer uploads a leaf photo; the frontend sends it to the isolated Flask inference service, where the image is resized, normalized, and edge-enhanced to amplify lesion and streak patterns before classification. The model performs strongest on diseases with distinct visual signatures — Tungro, Brown Spot, Leaf Scald — and the confusion matrix shows exactly where it struggles: visually overlapping lesion types like Leaf Blast and Narrow Brown Leaf Spot, the known frontier for expanding the dataset.

  • Bacterial Leaf Blight
  • Brown Spot
  • Healthy Rice Leaf
  • Leaf Blast
  • Leaf Scald
  • Narrow Brown Leaf Spot
  • Rice Hispa
  • Sheath Blight
  • Tungro

Measured results

76%
Disease classifier accuracy

9-class VGG16 · 10,689 images

95%
Pest model v2 accuracy

Up from 87% after dataset rebalancing

5.03%
Price forecast MAPE

226 records · significant at 95% CI

4.22/5
ISO/IEC 25010 quality score

55 respondents · all 9 categories rated High

Engineering highlight — reading past the headline metric

Pest model v1 reported 87% accuracy — but its precision–recall asymmetry revealed overfitting to a 2,000-vs-300 class imbalance: the model rarely missed pests because it called nearly everything a pest. We rebuilt the dataset to a near 1:1 ratio, applied heavy augmentation, and retrained. v2 reached 95% accuracy with balanced per-class F1 — a reminder that a single headline number can hide a model that doesn't generalize.

Supporting modules

Pest detection
A separate binary CNN answering the question farmers actually asked: is there pest damage, yes or no? Deliberately simple to keep the diagnostic flow accessible.
AskJuan — Filipino-language assistant
Structured library of predefined, selectable Filipino Q&As curated from DA–PhilRice, the IRRI Rice Knowledge Bank, and extension-worker interviews — chosen over a free-form chatbot to guarantee accuracy.
Farming calendar
Per-user task scheduling (Magtanim, Mag-abono, Magpatubig, Mag-ani) on Firebase Authentication and Firestore, guided by documented Philippine rice crop durations.
Price listing & forecasting
Node.js backend serving cleaned Department of Agriculture Bantay Presyo data, with a linear regression module (R² 0.56, MAPE 5.03%, p < 0.05) estimating short-term price movement.

My role: backend architecture, database design, and cloud implementation; building the VGG16 disease model and integrating it into the Flask REST API; and developing the price regression module, AskJuan, and the farming calendar — while my teammates led field research and dataset curation, from farmer interviews to the AskJuan knowledge base.

Recognition

  • 1st Place — Technology Exhibit at CONTRENDS 2026
  • 2nd Place — Best Thesis under the Department of Computer Science (DLSU-D), 2026
  • Best Paper Presentation Finalist — ICAI 2026

Scoped honestly: Rice Up is a supplementary decision-support tool — it does not replace agronomists, field technicians, or laboratory diagnostics.

demo note: the platform is fully live; disease and pest inference runs on an on-demand cloud runtime — heavyweight CNN models exceed free-tier hosting, so inference was isolated as a separate service and the platform degrades gracefully when it's offline.

Internship · Hacktiv Colab Inc. · 2025

Inventory Management API

Cloud-based inventory backend built during my internship: five domain modules (items, categories, suppliers, transactions, image uploads) as independent Flask blueprints with Pydantic request validation, deployed serverless on Azure Functions with Cosmos DB and Blob Storage.

Course Project · Software Engineering · 2024

XPENDITURE

Expense management platform where I owned the backend: REST APIs for budgets, expense tracking, group budgeting, and transactions, with JWT authentication, middleware-based input validation, and endpoints verified through Postman.

Experience

  1. Jul – Aug 2025

    Backend Developer Intern

    Hacktiv Colab Inc.

    Built a cloud-based inventory management backend in Python, deployed serverless on Azure.

    • Designed five domain modules (items, categories, suppliers, transactions, images) as independent Flask blueprints with Pydantic request validation.
    • Implemented transaction integrity across Cosmos DB containers with a two-pass validate-then-mutate design and compensating rollback on failure.
    • Integrated Azure Cosmos DB and Blob Storage, and shipped the API as an Azure Functions app via WSGI middleware.
  2. Aug 2022 – Aug 2026

    Bachelor of Science in Computer Science — Intelligent Systems

    De La Salle University–Dasmariñas

    Built a strong foundation in software development and intelligent systems, culminating in a thesis that left the lab and reached real users.

    May 2025 – May 2026

    Rice Up — undergraduate thesis

    CNN-powered disease detection platform for palay farmers in Naic, Cavite. 1st Place Technology Exhibit, 2nd Best Thesis.

    read the case study ↑

Skills

Backend engineering

  • Flask
  • Express.js
  • REST API design
  • JWT authentication
  • Pydantic validation
  • Modular architecture
  • Event-driven programming

AI & machine learning

  • TensorFlow
  • scikit-learn
  • CNNs & transfer learning
  • Image classification
  • Regression analysis
  • Model integration
  • Prompt engineering

Cloud & databases

  • Azure Functions
  • Cosmos DB
  • Blob Storage
  • Firebase Auth
  • Cloud Firestore
  • MongoDB & Mongoose
  • Schema design

Data analysis

  • Pandas
  • NumPy
  • Matplotlib
  • Seaborn
  • Jupyter Notebook
  • Google Colab

Languages & tools

  • Python
  • JavaScript
  • HTML & CSS
  • Java (familiar)
  • Git & GitHub
  • Postman

How I work

  • Listens first, thinks critically, stays open to better approaches.
  • Learns independently; treats feedback as data, not criticism.
  • Composed under pressure, curious about root causes.
  • Follows through — on details, commitments, and teammates.

Recognition

  1. [01]

    1st Place — Technology Exhibit

    2nd Conference on Technology and Research for National Development and Sustainability · 2026

    Rice Up, selected over competing thesis projects within De La Salle University–Dasmariñas.

  2. [02]

    2nd Place — Best Thesis

    De La Salle University–Dasmariñas · 2026

    Second-best thesis under the Computer Science department.

  3. [03]

    Best Paper Presentation — Finalist

    International Conference on Artificial Intelligence 2026

    Rice Up, named as one of the top 5 best papers over several competing submissions.

Certifications

Cisco Networking Academy
Linux Essentials
Operating Systems Basics
Introduction to Cybersecurity
Introduction to JavaScript
WPH Digital Workshop
Generative AI Awareness & Effective Prompting
Designing for Humans — UX Psychology
Pearson
Versant English Placement Test

Contact