Mateus Lemos Figueiredo Jiyu Henko

Software engineer & founder

I build useful software,
often with AI in the loop.

I work across applied AI, developer tools, automation and customer-facing software. I care about understanding the problem, building quickly, and verifying what actually works.

Building software since 2016 ~30 client engagements Brazil · open to São Paulo
2024

Violet

Tool-using AI assistant with local actions, browser automation, persistent context, execution feedback and human approval.

↗
2026

Agentic SDLC

A practical workflow for coding agents built around explicit context, bounded authority, CI gates, read-back and evidence-based completion.

↗
Custom Mind

Project Fit

Private fitness SaaS using React Native, SQLite, Supabase/Postgres, RLS and an AI-assisted development harness.

private
Experiment

Hytale Automator

Visual automation combining perception, telemetry, normalized world state, demonstration datasets and explicit safety constraints.

private
2024 — present

Founder & Software Engineer · Custom Mind

Custom software, automation, applied AI and technical consulting. Roughly 30 client engagements across automotive, real estate, healthcare, fitness, retail, food service and other areas.

Mar 2026 — present

Software Quality & Automation Intern · PRODEMGE

Playwright-based automation, regression investigation, reusable test components and data-driven coverage in a corporate software environment.

~2018 — 2024

Independent technical work

Paid technical support, software development and automation while continuing formal and self-directed study.

I like learning how systems work, getting good at the process, and then making the process better.

I started with C, later learned Java, Python, Ruby on Rails and modern JavaScript/TypeScript stacks. Over time I became more interested in the systems around software: automation, quality, customer workflows and, more recently, coding agents and applied AI.

My approach is simple: understand what matters, avoid unnecessary complexity, build the smallest useful version, and verify the result against the real system.

Languages C · Python · JavaScript · TypeScript · Java

Web & product Node.js · React · React Native · APIs · SQL · PostgreSQL · SQLite · Supabase

Engineering Playwright · Git · GitHub Actions · Docker · AWS · CI · automation · coding agents

Human languages Portuguese — native · English — fluent · Spanish — fluent

Contact

mateusllemosf@gmail.com