Guilherme Jenner Gomes de Abreu Full-stack software engineer · Vila Velha, Brazil

Full-stack engineer shipping generative AI to production.

.NET 8, Angular, Flutter and Google Cloud. I design, build and maintain complete products, from the database to the mobile UI, with a focus on performance and on AI that doesn’t break when it meets real data.

Experience: 5 years — .NET, Java, Angular, cloud
Location: Vila Velha, Brazil — remote (UTC−3)
Languages: Portuguese (native), English (advanced), French (intermediate)
Engagement: Contractor through a registered Brazilian company

Engineering in production

CLO

Social network, virtual closet and AI stylist · App Store and Google Play

Co-founder and sole developer: architecture, backend, mobile, infrastructure and release · Jan 2026 – present

users in 5 months: 4,000+
onboarding: 90%
feed latency: ~3s → ~200ms

Resilient multimodal pipeline

Async Gemini / Vertex AI via Hangfire: per-item embeddings, Lab color palettes, idempotent jobs and backoff on 429/503.

Safe parallel function calling

Transactional assistant with propose → confirm, double-execution protection and token quotas per subscription tier.

.NET 8 + EF Core

Removed startup connection overhead (−1.2 s per request) and kept BLOBs out of hot queries (5 → 3 round-trips).

Flutter at 60 FPS and payments

Moved the feed from an Ionic WebView to Flutter; idempotent RevenueCat webhooks; Cloud Run + Cloud SQL over Direct VPC.

.NET 8
EF Core
Flutter
Angular/Ionic
Vertex AI
Google Vision
MySQL
Hangfire
Cloud Run

Read the full case study

Beluga Analytics

IoT and retail intelligence SaaS

Co-founder and sole developer · Oct 2024 – Dec 2025 · pilot validated with a consumer-goods multinational; development paused pending hardware

Read the full case study

.NET SaaS (Clean Architecture) and Angular 17+ with RxJS and Signals.
Retail data ingestion in BigQuery and predictive reports with Vertex AI.
Docker on Cloud Run, CI/CD, JWT and secrets in Secret Manager.

Stack

Backend and architecture

C# · .NET 8 · ASP.NET Core · EF Core · Clean Architecture · Java · Spring Boot · SignalR · Hangfire · REST · idempotency and messaging

Frontend and mobile

Angular 17+ (Signals, Standalone) · TypeScript · RxJS · Flutter · Ionic / Capacitor · React · SCSS

AI and data

Vertex AI · Gemini API (function calling, embeddings) · Google Vision · BigQuery · SQL Server · MySQL · Oracle · query tuning

Cloud, DevOps and security

GCP (Cloud Run, Cloud SQL, Pub/Sub, Secret Manager) · Azure · Docker · CI/CD (Codemagic, GitHub Actions) · Linux · Google Cybersecurity Certificate

Experience

Jan 2026 – present CLO Co-founder, sole developer AI fashion app from zero to production: .NET 8, MySQL, Hangfire, SignalR, Flutter, Vertex AI and GCP.
Oct 2024 – Dec 2025 Beluga Analytics Co-founder, sole developer IoT and retail analytics SaaS in .NET, Angular 17 and BigQuery; pilot with a multinational.
Jun 2024 – Aug 2025 Prosperi Full-stack (internship) High-availability business systems in .NET and Angular; SQL Server queries, views and stored procedures; code review and Scrum.
Jan – Jun 2024 Circo Filmes Frontend (freelance) Angular company website focused on performance, SEO, accessibility, lazy-loaded HD video and i18n. circofilmes.com
Dec 2021 – Dec 2023 Vixteam Consultoria & Sistemas Full-stack (trainee) Java (Spring Boot) and Angular for consulting clients; SQL Server, MySQL and Oracle in production with Docker and Azure.
Open source Lightshot for Pop!_OS Native Linux screenshot app, filling the gap left by the lack of a Lightshot equivalent in that ecosystem. View on GitHub
2021 – 2025 UVV B.Sc. in Information Systems. Google Cybersecurity Certificate (2024).