Full-Stack Developer — based in Brazil. Building production software at Arctic Leaf Inc. — SaaS platforms, e-commerce storefronts, serverless data pipelines, and ERP integrations.

I started in Electrical Engineering and ended up deep in software, drawn by the same thing: building systems that work precisely and reliably. I like the parts of the job most people avoid — distributed state, third-party API complexity, schema design that has to survive real-world load.

Curated marketplace installable via /plugin marketplace add mqmalagris/claude-skills. Headline skill is swe-compass, a multi-mode software engineering coach that routes intent across architect/advisor/reviewer/refactor/explain workflows — stack-agnostic by default, defers to the user's chosen stack, then optimizes for that stack's idioms (skips Singleton suggestions for Rust where lazy_static! solves it natively). Progressive-disclosure layout: SKILL.md router, 5 workflows, 9 topics (SOLID, GoF subset, TDD, refactoring, DevOps, processes, requirements, modeling), 10 cross-cutting reference tables, 5 checklists. Plugin manifest at .claude-plugin/marketplace.json registers skills with category/keywords/semver.

Pure-Rust fixed-income interpolation and parametric fitting: piecewise linear, natural cubic spline (C² via Thomas tridiagonal solver), Nelson-Siegel (1987), Svensson (1994). Zero third-party numerical crates — bundles its own Nelder-Mead simplex optimizer. unsafe_code = "forbid" at the crate level, with a post-fit sanity check so callers can deterministically fall back to the spline when the optimizer lands on an implausible mode. Published to crates.io.

140+ static Astro pages with Svelte 5 islands — every calculator is a pre-rendered HTML page that hydrates one interactive component. Build-time sync of Selic/CDI/IPCA/IGP-M/INPC/TR from my own Indicadores-BR API. Full Brazilian tax & payroll suite (IRPF, FGTS, rescisão CLT, INSS, Simples Nacional, MEI, 13º), real-estate financing with composable extra-payment strategies (SAC vs Price), symbolic-calculus parser, 2D/3D function plotters. All math runs client-side.

Go Lambdas + Terraform-managed AWS (SES inbound, S3, DynamoDB with TTL auto-delete, API Gateway, Route53). Astro + Svelte 5 web, React Native + Expo mobile, shared TypeScript API client — all in a Turborepo monorepo.

Languages

Frontend

Mobile

Backend

Databases

Cloud & Infra

Tooling & Testing

B.Eng. Electrical Engineering — CEFET-RJ, Brazil. The engineering mindset stuck: understand the system, find the constraint, fix it properly.

• Email — malagrismatheus@gmail.com