Kevin Castro
kevingcm
Available for hire
I'm a mobile developer based in São Paulo building cross-platform apps and clean interfaces with Flutter and Dart.
About
Download CVI'm a mobile developer, and Flutter is where I feel most at home. There's something satisfying about shipping one codebase that runs everywhere without cutting corners on how it feels to use. I like building things end-to-end: architecting the data model, wiring up the backend, then spending real time on the small interactions most people won't consciously notice but will definitely feel if they're missing.
Outside of code, I spend most of my free time on music, film, and books. I think all three feed into how I build too, especially when it comes to pacing and knowing when to cut something that isn't working. I'm not big on chasing trends for their own sake. I'd rather spend time on things that actually hold up, in code and outside of it.
Education
IT Technician
Relevant Coursework
Experience
Kmon! Climb Club, Climbing App
Self Project
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Designed and built a full production app from scratch with Flutter + Supabase, managing 50+ database migrations and defining the entire data architecture including parallel schemas for outdoor climbs and indoor gyms.
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Implemented full Row-Level Security (RLS) in PostgreSQL, per-table access policies, three-level privacy control (public/followers/private), and authenticated media upload via Supabase Storage.
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Built a full social graph, follows/followers, activity feed from followed users, check-ins with photos and notes, likes and comments on visits, and public profiles with follower counts.
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Built search with 250ms debounce, combined filters (difficulty, distance, rating), dynamic sorting, and Google Maps integration displaying nearby location pins using the device's GPS.
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In progress: gym route catalog with a vote-based send verification system (3 votes to confirm + staff override), time-scoped rankings (monthly/yearly/all-time), and competition groups with leaderboards.
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Implemented Material 3 theming with dark mode and accent color picker, parallax image carousels, optimistic state with error reversal, modal bottom sheets for transient actions, and user-curated lists with three privacy tiers.
RecipeSZ, Recipe App
Self Project
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Built a full recipe app with Flutter running on Android, iOS, and Web from a single codebase, with go_router for navigation and Riverpod for state management.
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Implemented Google Sign-In auth, Cloud Firestore with per-account data isolation, image uploads via Cloudinary, and monitoring with Firebase Analytics and Crashlytics.
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Built photo reviews, an admin moderation queue, in-app notifications, user profiles with customizable avatars, and seamless multi-account switching.
OOP Teaching Assistant
Instituto Federal de Rondônia
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Assisted students with Python programming concepts and exercises, answering questions and reinforcing the course's theoretical foundation.
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Led reinforcement sessions focused on exercise solving and programming logic development.
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Supported the teacher in reviewing assignments and projects, contributing to standardization and assessment quality.
Tech Stack
Flutter
Dart
Python
HTML5
CSS3
JavaScript
GitHub
PostgreSQL
VS Code
Figma
Git
GitLab
Kotlin
Swift
Projects
Kmon! Climb Club de Escalada
play.google.com/store/apps/details?id=kmon.climb
Full-stack climbing discovery app for Android and iOS. Outdoor crags and indoor gyms, social check-ins, route rankings, user-curated lists, and a real-time activity feed, built with Flutter and Supabase.
RecipeSZ, Recipe App
github.com/kevingcm/recipeSZ
Cross-platform recipe discovery app with favorites, cloud-synced shopping lists, pantry matching, community reviews with photos, and multi-account support, built with Flutter and Firebase.
DiaryApp, Personal Journal
github.com/kevingcm/diaryApp
A minimal, privacy-focused diary and mood tracker for Android and iOS. Local-first encrypted storage, rich text entry, mood tags, and daily reminders, built with Flutter.
Dadoos, Dice Roller
github.com/kevingcm/dadoos
A playful, multi-platform dice rolling app. Features roll animations, custom Material themes with soft pink palettes, and responsive layouts built with Flutter.
Calculadora, Calculator App
github.com/kevingcm/calculator
A clean, responsive basic calculator built with Flutter. Built with local state management and custom components to handle basic arithmetic, clear/delete, and decimal operations.
Shortly, URL Shortener
github.com/kevingcm/urlShortener
URL shortener with per-link click analytics. One Flutter codebase targeting web and Android, backed by a Node.js + PostgreSQL API with timestamp, referrer, and user-agent tracking.