Professional work, anonymized, 2026 - present
AI-first online banking platform
A credit and banking platform designed AI-first: conversational AI handles first contact and onboarding, and a modular core owns credit, anti-fraud and formalization.
From problem definition to production.
I'm Guilherme Martins, a Software Engineer focused on product engineering and software architecture.
I build and evolve full-stack products, integrating AI capabilities where they make sense. I use coding agents throughout the development lifecycle in a spec-driven workflow with scoped tasks, tests, and human review.
I've partnered with Brazilian and international teams across diverse domains, including fintech, SaaS, AI-powered solutions, healthcare, real estate, and creative technology.
Professional identity map
Full-stack Engineering
Frontend · backend · APIs · system integration
Product Engineering
Problem framing · end-to-end ownership · product iteration
Software Architecture
System design · technical trade-offs · reliability
Agentic Engineering
Coding agents · spec-driven workflows · verification
AI-powered Products
LLM integration · tool use · guardrails
Communication & Collaboration
International teams · fluent English · clear communication
Product thinking , Engineering rigor , AI leverage , Human judgment
AI amplifies my capabilities; critical thinking and experience guide my decisions.
Cases
Independent product, Sep 2026 - present
Priorize.me
A collaborative prioritization app built on the Eisenhower matrix, with shared boards that update in real time. In public beta.
Open source, Aug 2026 - present
sdd-agentic-flow
An open-source harness that makes coding-agent work spec-first, bounded and verifiable, with people keeping the final say.
What I work on
How I workProduct engineering across the stack
From requirements and architecture to delivery and production support, in my own SaaS and in client systems for healthcare and food service.
Priorize.meSoftware architecture
Systems that replay ingested events, and payment APIs that are idempotent, so a retry never charges twice (modular hexagonal cores, replayable event ingestion, idempotent payment APIs). Decisions are recorded as ADRs. On the frontend, application architecture and a design system built from the first version.
Payments API projectAgentic engineering
Spec-driven development with coding agents: specs, bounded tasks, tests and human review in every change.
sdd-agentic-flowAI-powered product features
LLM integrations with guardrails in an AI-first credit platform, where AI speeds up the flow and people and rules make the decisions. In Priorize.me, an MCP server lets AI clients list, create and move tasks with the account's own permissions.
AI-first platform case study
Where I have worked
Full backgroundAI-first fintech
Senior Software Engineer
2026 - present
gmartins.dev
Software Engineer
2025 - 2026
Nisien.ai
Software Engineer
Mar 2025 - Jun 2025
Backbase
Software Engineer
Oct 2024 - Feb 2025
Vochlea
Software Engineer
Jan 2024 - Aug 2024
Loop
Software Engineer
Apr 2023 - Oct 2023
ChatWith.io
Frontend Developer
Oct 2022 - Mar 2023
Freelance
Full-Stack Developer
Sep 2021 - Oct 2022
Client and community work
Client website
Débora Blaso
Professional website for a clinical psychologist and image consultant in Belo Horizonte, built with React, Vite and Tailwind CSS, with PostHog and Vercel analytics.
Client product site
Psicologia da Moda Clube
Landing pages for the same client's study group for psychologists, built with Next.js and focused on technical SEO, answer-engine readiness and mobile conversion.
Community project
links
A community-maintained list of free tools and resources for developers, started in 2022. More than 400 stars and 15 contributors on GitHub.
