Senior software engineer who loves working with AI
Ruby on Rails since 2010, remote the whole time. I work on legacy applications, performance bottlenecks and refactors that need care — and lately I build with AI agents, which is the part of the job I enjoy most right now.
- Build
- Ruby on Rails · PostgreSQL · Python · FastAPI · Vue/Nuxt
- With AI
- Claude Code · LLM APIs · pgvector · agentic workflows
I'm Marcelo, a software engineer working with Ruby on Rails since 2010 and, more recently, building AI-powered products and engineering workflows. I enjoy solving high-complexity problems: legacy systems, critical refactors, performance bottlenecks, and projects that need to move fast without becoming fragile.
I'm naturally proactive. When I spot an opportunity to create leverage — a slow system, a repetitive workflow, a product gap — I prototype a solution, validate its impact, and help turn it into production. Seven years as CTO, Engineering Manager and Tech Lead taught me to bridge business and engineering, aligning stakeholders while delivering measurable outcomes. Today, driving AI adoption is also part of my role, across engineering and the company.
Recent examples:
- Reduced P95 response time by 73.5% (1,700ms → 450ms) on a legacy Rails SaaS, through an agentic optimization loop.
- Built LARA, an AI support assistant that researches tickets across documentation, repositories and development environments before drafting responses for human review.
- Built Aurora, a conversational AI platform that opens up natural-language access to company data, using dialogue state tracking, semantic caching, vector search and LLMs.
- Introduced agentic AI code review, where specialist agents review every pull request before human review begins.
I've worked remotely since 2010 and I'm at home in asynchronous, international teams. If you're looking for someone to modernize a Rails application, accelerate AI adoption, or lead a complex engineering initiative, let's talk.
People I've worked with
What people who worked closely with Marcelo have to say.
"Marcelo has a unique ability to turn challenges into fast, efficient solutions using AI. Working with him is a constant learning experience. His creativity and delivery are impressive."
Software Engineer at Portábilis
"Working with Caju has been a truly transformative experience. He impresses not only with his command of AI applied to products, but above all with the speed at which he builds high-quality solutions..." "Working with Caju has been a truly transformative experience. He impresses not only with his command of AI applied to products, but above all with the speed at which he builds high-quality solutions. Since we started bringing AI into our development processes — under his direct guidance and collaboration — the gains have been enormous: we drastically cut development time, automated repetitive tasks, improved code quality, and opened up possibilities that once felt out of reach for our team. He has a rare ability to turn complex needs into concrete deliverables, always with a very practical, results-driven mindset. Caju is, without a doubt, one of the most visionary and productive people I've ever worked with."
Head of Product at Portábilis
"Before AI, I saw myself as a 6-out-of-10 developer, struggling to get from idea to delivery. With Caju, AI stopped being something complex and became a daily tool, the barrier to thinking and planning dropped, tests became routine..." "Before AI, I saw myself as a 6-out-of-10 developer, struggling to get from idea to delivery — the barrier was just too big. With Caju, AI stopped being something complex and became a daily tool, the barrier to thinking and planning dropped, tests became routine and, most importantly, the curiosity and excitement to build came back. My productivity took a surreal leap, it was a turning point, and I believe the benefits will only keep growing as the technology itself evolves."
Software Engineer at Portábilis
"I started AI mentoring with Caju and 15 days later the change in my productivity as a Product Manager was obvious. Caju pointed me to paths that streamlined my day-to-day processes..." "I started AI mentoring with Caju and 15 days later the change in my productivity as a Product Manager was obvious. Caju pointed me to paths that streamlined my day-to-day processes, like writing user stories, prototyping faster, and pulling data from the team's workflows to get evidence on how to improve. On top of that, he brought a mindset of using AI to optimize repetitive processes so there's room for creativity. I'm still getting used to the tools AI has made available, but I already notice a gain in operational productivity and time to create and reflect on new initiatives."
Juliana Saito
Product Manager
Where to find me
LinkedIn, GitHub, or email — just pick a channel.