Mid-Level Backend Engineer with FinTech Focus

Ronald Dias

**************@*****.*** linkedin.com/in/ronalddiasdevux github.com/RonaldDias

Summary

Software Engineer with focus on Backend Development with experience in Java, C# and Node.js, working in high-stakes financial systems in the banking sector and payment projects. Hands-on experience with REST API integration, traffic control (TPS/TPM), SLA monitoring and LGPD compliance. Independent developer of Acai Gest, a point-of-sale SaaS currently in production, built and operated end-to-end including infrastructure, CI/CD, database and frontend. Seeking a remote mid-level backend position.

Experience

Backend Developer (C#, .NET, SQL Server, Git, Jira) Jul. 2025 – Dec. 2025 Sofintech Brazil

• Designed and implemented a complete observability solution for an Open Finance integration, covering traffic control (TPS/TPM), SLA monitoring and LGPD compliance, ensuring full traceability of more than 10,000 bank transactions monitored per day.

• Developed in C# with SQL Server and Redis, collaborating in multidisciplinary squads with continuous delivery in a mission-critical environment, maintaining 99.9% availability across integrated endpoints. Backend Developer Analyst (Jasper Reports, Cherwell, Tortoise) Nov 2024 – Jul 2025 Montreal Informatica Brasil

• Resolved over 90% of client-reported incidents in financial applications, ensuring continuous transaction flow ranging from R$ 5,000 to R$ 1,500,000.

• Optimized SQL Server queries and database processes through index tuning and query rewrites, reducing processing time by up to 40% with direct impact on production application performance.

• Refactored and fixed bugs in legacy Java code in financial systems, reducing the production error rate by approximately 35% over 6 months.

Projects

Acai Gest Vue, NodeJS(express), PostgreSQL, Docker, GitHub Actions, Nginx, VPS Jan. 2025 – Mar. 2026

Built and independently operate a production SaaS: REST backend, Vue.js 3 frontend, PostgreSQL 16, Nginx as reverse proxy and SSL via Let’s Encrypt.

Implemented full CI/CD pipeline with GitHub Actions, automated daily backup to Cloudflare R2 and uptime monitoring with UptimeRobot.

Product covers sales management, inventory, cash flow control, vendor registration and period-filtered reports, with API documentation via Swagger.

DriveWatch Automotive Monitoring SaaS Flutter, Node.js, Java, PostgreSQL, Docker, FCM 2026 – presente

Designing and developing a vehicle monitoring SaaS platform via 4G OBD-II dongle, with real-time data processing under 5 seconds and WebSocket display on mobile app (Android and iOS).

Service-oriented architecture: ingestion service in Java/SpringBoot, main API in Node.js, push notifications via Firebase Cloud Messaging and on-demand PDF report generation.

Applying Clean Architecture, Repository Pattern and Observer/Event across all layers, with three subscription tiers (Basic, Pro and Enterprise) and a recurring revenue model. Technical Skills

Professional use: Java, C#, .NET 8, SQL (SQL Server, PostgreSQL), JavaScript, Node.js, Vue.js 3, Docker, Git Solid knowledge: Spring Boot, Express.js, JUnit, Redis, GitHub Actions, Nginx, Swagger Familiarity: React, Flutter, AWS (basic)

Tools: Jira, Postman, Notion, WSL, Cloudflare, R2, UptimeRobot Education

Analysis and Systems Development Jan. 2022 – Dec. 2024 Universidade Estacio de Sa Belem, PA

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