Gabriel
Malenowitch
Software Engineer III
Software Engineer — I work at the largest publicly traded fintech in Brazil. I earned 4 promotions in 3.5 years by shipping software that moves real business metrics: a financial security tool that saves 40 hours/month and R$24,000+ annually, shared components used by 50+ developers across a system serving 1,518 active users, and regulatory compliance implementations that averted heavy fines.
My core stack is React, TypeScript, and Next.js — but I work across the full engineering cycle: distributed systems architecture, end-to-end observability, cross-team collaboration, and mentoring junior devs. I’m the person teams call when the scope is vague, the deadline is tight, and quality can’t slip.
Currently also building Dontosys from scratch — a multi-tenant SaaS CRM for dental clinics — handling everything from infrastructure and authentication to product.
4+
SE III
B2B SaaS & Fintech
How I work
Extreme Ownership
End-to-end accountability for everything I build — from spec to production monitoring. I advocate for the customer internally and raise engineering standards across the team.
Architecture that Scales
Architectural decisions on distributed systems backed by full observability: logging, tracing, profiling, and metrics. Resilient software that holds under pressure.
Measurable Impact
I navigate ambiguous scenarios with data-driven decisions. I balance impact vs. investment to deliver results that move real business metrics.
Blog
Articles on software architecture, frontend, and career behind-the-scenes — straight from my day-to-day building production systems.
Featured projects
Dontosys
SaaS for Dental Clinic Management
Full multi-tenant SaaS CRM I designed and built from scratch for dental clinic management — architecture, infrastructure, authentication, and product. Keycloak-based multi-tenant auth, complex PostgreSQL database modeling, scalable NestJS RESTful API, and a Next.js admin interface. Covers the complete clinic lifecycle: patient onboarding, medical records, scheduling, and billing. An exercise in full product ownership across the entire stack.
A high-performance 3D voxel rendering engine built 100% in pure JavaScript, with no external engines. Implements raycasting, procedural terrain generation using Perlin noise, and renders interactive voxel worlds directly on the browser canvas. A project born from curiosity that proves environmental constraints are just starting points for creative solutions.
Click to play
Press ESC to release the mouseOpen-source calendar component for React with Material-UI and TypeScript, inspired by Google Calendar. Supports month, week, and day views with full event management — creation, editing, deletion, conflict detection, and drag-to-select. Published on npm with comprehensive Storybook documentation and Cypress test coverage.
Complete photo editor running 100% in the browser with no server uploads. Crop, remove backgrounds with AI, apply filters, add text overlays with Google Fonts, and compress images — all processed locally. Built with Next.js, Material-UI, and client-side Canvas APIs for a fast, privacy-first editing experience.
Lossless image compressor running entirely in the browser — no uploads, no servers. Drag and drop your images and get optimized files instantly. Supports PNG, JPG, WebP, AVIF, and GIF. Built with Next.js and Material-UI, 100% free with no limits.
Calculate the growth of your investment with compound interest. Visualize portfolio composition with a stacked bar chart and estimate monthly retirement income using the 3% and 4% safe withdrawal rules (Trinity Study).
Timeline
Software Engineer III
Stone
At Stone, I operate with full autonomy on the highest-complexity challenges — making architectural decisions for a distributed system serving 1,518 active users, used daily by 50+ developers. I deliver end-to-end observability: structured logging, distributed tracing, profiling, and metrics. Selected cross-team to deliver critical quarterly-goal features in record time, and implemented mandatory regulatory changes that averted tens of thousands of reais in fines. I also mentor junior engineers through high-impact technical decisions.
Software Engineer II
Stone
Contributor to Stone's large-scale internal CRM across Banking, Payments, Risk, and Identity domains. Fixed and improved 10+ shared components — each used in hundreds of places by 50+ developers for 1,518 active users. Contributed to an internal dashboard that reduced tens of thousands of customer clicks per month. Participated in high-level architectural decisions and drove cross-team operational efficiency improvements.
Software Engineer I
Stone
Part of the frontend team that built and maintained Stone's mission-critical internal CRM — the system centralizing operations for the entire company group. Delivered management features across Banking, Payments, Risk, and Identity domains that improved operational processes and client support quality. Full engagement from brainstorming to production, no shortcuts.
Frontend Developer Trainee
Stone
First professional role — joined Stone as a trainee in a high-performance environment focused on risk management, identity verification, and digital banking. Built responsive, secure interfaces side-by-side with senior engineers, rapidly absorbing financial sector best practices. The foundation of a track record that led to 4 promotions in 3.5 years.
Full-Stack Engineer
Highlander TECH
Full-stack development on a platform handling 90,000 monthly accesses — building scalable NestJS APIs with caching strategies and dynamic Next.js UIs. Improved front-end architecture and system design, refactored backend data pipelines, and shipped new features end-to-end with a strong focus on performance and code quality.
