Built SisTech from scratch, working directly with the client on requirements and improvements to operational workflows. Next.js/React, ASP.NET Core and PostgreSQL support access records, role-based permissions, audit trails and Protheus service requests. The production system continues to evolve through separate preproduction deliveries, illustrated in the linked captures.
I-repos 1: Android application distribution
Production platform
Technos through IPena Consultoria / Professional development
APK catalog, targeted releases, device tracking and a Flutter updater.
Built the production distribution platform and updater from scratch and maintain their integration. NestJS/Prisma APIs and Next.js administration manage releases, while the Flutter updater verifies SHA-256 integrity and hands installation to Android's installer. I-repos 2 explores device-management capabilities as a separate pilot.
Factory app: multi-release development
Inherited production app
Technos through IPena Consultoria / Professional development
Features and fixes for a Flutter Android application used on factory handheld scanners and tablets.
Delivered substantial features and fixes across multiple releases of an inherited production application. Flutter/Dart work covers Protheus API integrations, barcode workflows and landscape-device usability. The linked captures show candidate interfaces in an Android emulator.
Ranking: logistics dashboards
Production application
Technos through IPena Consultoria / Professional development
Operational and management views over Protheus logistics data.
Built the Flutter Web application and server-side Dart proxy for Protheus logistics data. Shared requests, bounded retries and retention of the last complete dataset preserve context when an upstream refresh fails. The linked capture shows a filtered preproduction view.
Payroll administration and AWS migration
Production software and cloud
Through IPena Consultoria / Professional development and operations
Non-fiscal payroll calculation, HR administration, monthly closing and a simpler AWS hosting model.
Developed and deployed the non-fiscal administration platform from an unfinished baseline using Flutter Web, TypeScript/Express and PostgreSQL, with recurring workflow support. Migrated ECS/EC2/RDS hosting to Lightsail/Docker/PostgreSQL while retaining S3/CloudFront delivery and off-host backups. Performed documented isolated restores and data-parity checks during the migration.
IPena institutional website
Delivered static website
IPena Consultoria commercial brand / Professional development
Brand information and contact channels delivered through static cloud hosting.
Built the website from scratch and deployed a Next.js/React static export using TypeScript. Configured AWS S3 hosting, CloudFront delivery and Route 53 DNS for the institutional site.
Python Android QA automation and CI/CD
Internship / 2023-2025
INDT / Professional internship contribution
Python automation and device troubleshooting for Android validation and regression workflows.
Contribution and context
Developed Android test cases in Python using pytest and an internal automation framework. Used UI Automator, screen XML hierarchies, widget attributes and navigation-flow analysis, with Android Studio and ADB for device troubleshooting. Configured Jenkins CI/CD test-execution workflows and SSH connections; Cypress and Gerrit also supported QA execution and review.
Independent and historical work
Freelance delivery across frontend development, assistants, desktop workflows and migration.
Project-management frontend
Delivered frontend MVP
Independent engagement / Professional frontend development
A project-management interface delivered in a separate freelance engagement.
Contribution and context
Developed and delivered a project-management frontend MVP using Next.js, React and TypeScript. The engagement focused on the application interface and frontend workflows.
Client-context WhatsApp assistants
Freelance contribution / 2024
Independent engagement / Professional contribution
Contributions to assistants tailored to different client contexts.
Contribution and context
Contributed to WhatsApp assistant workflows using Python, LangChain and LangGraph in 2024. Adapted an existing assistant base to different client contexts.
Offline service-receipt application
Historical initial application
Independent engagement / Flutter Windows
An initial offline tool intended to digitize automotive service receipts and look them up by vehicle plate.
Contribution and context
Developed an initial Flutter/Dart Windows application around the client's receipt templates and offline workflow. The historical engagement covered receipt digitization and lookup by vehicle plate.
Python business-application migration
Historical migration
Independent delivery / Existing Python systems
Migration of existing business applications between servers while preserving agreed behavior.
Contribution and context
Migrated existing Python business applications between servers. The engagement focused on preserving the agreed application behavior in the destination environment.
Personal tools and infrastructure
Active personal tooling and hands-on development and preproduction environments.
Career Hub
Active personal tooling
Personal project / Python, Node.js, static HTML, spreadsheets
Evidence-based resume, portfolio and application-tracking workflows.
Contribution and context
Develop and maintain bilingual resume generation, a static portfolio, job discovery and spreadsheet-based application tracking. Evidence review and human approval guide applications and publication; the tooling prepares material rather than submitting applications automatically.
Self-hosted development and preproduction
Personal platform
Personal infrastructure / Hands-on setup and operations
A repurposed laptop supporting project-specific application and database environments.
Upgraded an older personal laptop and configured Ubuntu, networking and project-specific Docker Compose runtimes for development and preproduction. Maintain scoped backups, checksum verification and selected isolated PostgreSQL restore exercises, with private SSH administration.
Pilots and prototypes
Product exploration in device management, ERP assistance and cafe operations.
I-repos 2: Android device management
Pilot
Android device-management product / Android and web development
Implemented pilot with kiosk and application policies, awaiting client clearance.
Developed a device-management pilot, separate from the I-repos 1 distribution platform. A Kotlin Android Device Owner agent and NestJS/Next.js administration implement kiosk and allowlist policies plus temporary view-only screen sessions. Client clearance is pending.
Built a Next.js/TypeScript console with separate business and technical conversations, calling Python tools through an API and worker. Implemented inventory, log analysis, database inspection, source lookup and read-only stock queries. A separate FastMCP server exposes ERP tools and basic local text search. Development is on hold at the prototype stage.
Archived screenshots illustrate the prototype interface, not tool execution or a production connection.
An engineering foundation for cafe and breakfast-service management.
Contribution and context
Implemented an initial application foundation using Next.js, TypeScript, Prisma and PostgreSQL. The prototype explored a multi-client SaaS direction for cafe operations before development was put on hold.
Research and academic work
Published academic work and applied R&D through internships and university scholarships.
Voice and LLM accessibility assistant
Published paper / Discontinued prototype / 2024
SBIE 2024 / Prototype implementation under academic supervision
Research into voice and text interaction with operating systems for students with visual impairments.
Developed the voice/text LLM research prototype using LM Studio and PostgreSQL under academic supervision. The study explores LLaMA 3, Mistral and Phi 3 for operating-system interaction by students with visual impairments. The project is discontinued; its SBIE 2024 publication and related PAIC prototype source remain available.
Desenvolvimento de um Assistente Virtual Baseado em Voz e LLMs para Facilitar a Interação de Estudantes com Deficiência Visual com Sistemas Operacionais
Nickolas J. S. Livero; Fabio S. Silva. SBIE 2024, Trabalhos em Andamento. Published , pp. 2987-2998.
Training and evaluation work on whether test cases are suitable for automation.
Contribution and context
Contributed to dataset preparation and normalization, training, fine-tuning and evaluation of BERT classifiers for test-case automation suitability using Python, PyTorch, scikit-learn and Transformers. Supported dataset-based experiments alongside separate generative AI exploration in the internship R&D setting.
Callidus and Information Systems research
Scholarship research / 2022-2023
LUDUS / Universidade do Estado do Amazonas / Academic and industrial R&D
Mobile migration, dashboards and computer vision in an embedded-system research setting.
Contribution and context
Worked on Callidus and other Information Systems projects within LUDUS, UEA's R&D hub. Contributions included legacy Java Android code, Flutter/Dart migration prototypes and React dashboards, plus Python/OpenCV computer vision, dataset processing, classification and model validation in industrial research.
Coursework and study archive
Earlier learning experiments in algorithms, web, mobile, embedded systems and AI.
Sorting-algorithm comparison
Inactive coursework
AED2-TRAB1 / C++ coursework
Comparison of seven sorting algorithms under different input arrangements.
Study context
Coursework comparing seven sorting algorithms in C++. Records execution time, comparisons and data movements across different input arrangements.
Educational demonstrations of hash-linked records and chain validation.
Study context
Related study variants explore vaccination records over local hash-linked chains. The Streamlit demonstration and FastAPI/Django variant are grouped by domain, covering chain validation and interface/API access.
Auction creation, bidding, bid history and owner-controlled closure.
Study context
Coursework connecting React views to Solidity auction contracts through Web3.js and Truffle. Bidding and history are demonstrated, while closure emits contract events without completing seller payment.
Room-based communication, key exchange and message-encryption exercises.
Study context
An educational chat prototype exploring RSA key exchange and 3DES message encryption. Python, Flask-SocketIO and SQLite support room-based messaging and persistence.
A chatbot experiment focused on Amazonian boi-bumbá culture.
Study context
A study combining a Streamlit chatbot interface with a language-model client. Dataset-preparation scripts explore material about Amazonian boi-bumbá culture.
Related experiments in case-based matching and K-means laptop clustering.
Study context
A study family exploring case-based equipment matching and K-means clustering by price and hardware specifications. PCBuildingSystem and AI-Laptops are related variants using Streamlit, pandas and scikit-learn.
Team coursework for monitoring pet environments and controlling food dispensing.
Study context
Team coursework exploring pet-environment monitoring and food-dispensing control. The prototype connects ESP32 firmware to MQTT, Flask, Node-RED and Alexa integrations.
A retrieval-augmented assistant combining document search and market-data queries.
Study context
A retrieval-augmented assistant experiment using document extraction, embeddings and ChromaDB to assemble language-model context. Gradio provides the interface, with yfinance for market-data queries.
Pizza-ordering interface
Inactive frontend prototype
Frontend study / React, client-side state
Reusable components and forms for registering and organizing pizza orders.
Study context
A React frontend exercise for registering and organizing pizza orders. Reusable components, forms and in-memory client state model the ordering interface.
Collaborative-filtering experiments based on user ratings.
Study context
A collaborative-filtering study based on normalized user ratings and Euclidean-distance similarity. A Streamlit interface presents the movie-recommendation experiments.
Authentication, class messages and point-based classroom tasks.
Study context
Coursework exploring classroom interactions with Flutter and Firebase services. Authentication, class messages and point-based tasks use Firestore persistence.
A desktop simulation of customers, current accounts and transactions.
Study context
Coursework modeling customers and current accounts in a Java Swing desktop application. Simulated deposits, withdrawals and statements exercise object-oriented programming and interface design.
Route optimization with visualizations of candidate solutions.
Study context
Coursework applying a genetic algorithm to the travelling-salesperson problem in Python. Visualizations show candidate routes and the evolution of solution quality.
Completed learning periods and discontinued prototypes across applications, ERP and operating systems.
Production-box checking prototype
Discontinued prototype
Historical development / Flutter, Protheus integration
An early application concept for checking the expected contents of production boxes.
Development context
Developed a Flutter prototype for checking expected items in a production-line box through Protheus requests. The project ended at the prototype stage before production use.
Merge PDF+
Discontinued experiment
Personal application study / Flutter, Dart, Riverpod, Syncfusion
Offline PDF merging, compression, rotation and sharing on Android.
Development context
Explored offline PDF workflows in a Flutter Android application using Riverpod and Syncfusion. The personal experiment covered merging, compression, rotation and sharing before development ended.
Parking-management demo
Archived MVP / Simulated detections
Personal prototype / FastAPI, SQLAlchemy, SQLite, Next.js, Flutter
A parking-workflow demonstration connecting a backend, dashboard and Android terminal.
Development context
Developed an MVP foundation with a Python/FastAPI backend, Next.js dashboard and Flutter Android terminal. Demonstrations use simulated plate detections rather than real OCR; the prototype is archived.
Liturgical-calendar study
Discontinued study
Personal frontend study / React, TypeScript, Vite
An initial web foundation for exploring the significance of days in the Catholic liturgical calendar.
Study context
Explored a React/TypeScript application foundation using Vite for a liturgical-calendar concept. The study ended during initial development.
Substitution-cipher exercise
Historical educational exercise
Personal programming study / Python
Character substitution and reversible alphabet mapping for learning basic cipher mechanics.
Study context
A Python exercise using a password-derived SHA-256 seed to shuffle a substitution alphabet. Reversing the mapping demonstrates decryption as an educational cipher.
Protheus setup and compilation study
Discontinued study
Personal learning / Protheus, ADVPL, TLPP
Environment setup and RPO-compilation attempts alongside language examples.
Study context
Explored Protheus environment setup, RPO-compilation attempts and ADVPL/TLPP examples. Compilation remained unresolved when the study ended.
Experimental macOS environments
Study ended
Personal environment study / macOS, virtualization
Operating-system and development-toolchain experiments on personal hardware and virtualized environments.
Study context
Explored macOS environment setup and development-toolchain compatibility, first on personal hardware and later through virtualization. The work remained an environment study and ended without an iOS product.
Campaign-to-messaging attribution
Historical study
Historical experiment / Advertising and messaging
Exploration of campaign click identifiers as a link to messaging conversations.
Study context
A historical experiment, described from personal recollection, explored linking campaign click identifiers to messaging conversations. Its focus was attribution, distinct from assistant development.
Client source code and operational data remain confidential. The study archive includes team coursework and sample-based experiments; descriptions summarize each artifact's purpose.
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