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Guilherme MartinsPT Português, ler em português

Cases

Case studies, the public products I helped build, and client and community work. Employer work is under confidentiality terms, so the professional case study is anonymized.

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.

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.

Products I worked on

Public products I helped build as an employee or contractor. The descriptions and screenshots come from each company's public site; the internal details of the work stay private.

The Hero Platform page on nisien.ai: "Detect online threats and resolve issues before they escalate".

Mar 2025 - Jun 2025, Cardiff, UK

Nisien.ai

Software Engineer

An AI platform that detects online threats and harmful content and helps teams resolve issues before they escalate, backed by research in cyber-risk detection, criminology and machine learning.

What I did

  • Built the main customer-facing application from its first version, focused on maintainability, usability and performance.
  • Designed the reusable UI foundations of the product's design system and component architecture.
  • Worked with the tech lead on frontend architecture and on decisions about application design, infrastructure and security.

Visit the product (Hero Platform)

The Backbase digital banking suite page, with mobile banking screens next to the headline.

Oct 2024 - Feb 2025, Cardiff, UK

Backbase

Software Engineer

A digital banking platform that retail and business banks use to build onboarding, servicing and lending journeys for their customers.

What I did

  • Built customer-facing features and composable frontend solutions for onboarding, servicing and lending with cross-functional teams.
  • Built a proof of concept of an AI conversational banking assistant for an internal hackathon. It won the competition.

Angular, TypeScript

Visit the product (Backbase)

The Vochlea home page: "Make the music in your head", above cards for Dubler 2 and DubBox.

Jan 2024 - Aug 2024, London, UK

Vochlea

Software Engineer

A creative tech company whose AI software, such as Dubler 2, lets music makers write, produce and perform with their voice.

What I did

  • Worked on the web team, not on the audio products: the website, the backoffice app, the API and the marketplace.
  • Built React, Next.js and TypeScript interfaces backed by a headless CMS and REST APIs.
  • Worked on Node.js and Express backend features, including authentication and OAuth2 integrations.
  • Worked with engineering, product, design and marketing to ship and evolve customer-facing software.

React, Next.js, TypeScript, Node.js, Express, OAuth2, Headless CMS, SCSS, Jest

Visit the product (Vochlea)

The Loop features page, with a preview of the estate agency dashboard below the headline.

Apr 2023 - Oct 2023, Moreton-in-Marsh, UK

Loop

Software Engineer

All-in-one software for UK estate agencies: sales pipelines, lettings and client accounting, used by agencies from small startups to national networks.

What I did

  • Built and maintained features of the property management CRM in Angular and TypeScript.
  • Turned requirements from product and sales into workflow improvements for estate agents.
  • Helped keep an existing production SaaS reliable while it evolved.

Angular, TypeScript, JavaScript, Angular Material

Visit the product (Loop)

The ChatWith.io home page in February 2023, from the Internet Archive: a form to create a WhatsApp chat link, under a menu of widgets, campaigns, polls, payments, bookings and inbox.

Oct 2022 - Mar 2023, Madrid, Spain

ChatWith.io

Frontend Developer

A SaaS platform for customer service and sales over WhatsApp: chat links and widgets, campaigns, polls, bookings, payments and a shared inbox.

What I did

  • Built and maintained customer-facing features of the web application in Vue.js.
  • Investigated and fixed frontend issues that affected users day to day.
  • Implemented responsive interfaces from product and design requirements.

Vue.js, JavaScript, Sass, Bootstrap

Visit the product (ChatWith.io)

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.

The home page of deborablaso.com.br, in Portuguese, with the psychologist's portrait and a call to meet her.

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.

The study group landing page, in Portuguese, with its title and a call to join the group.

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.

The links project page, a collaborative list in Portuguese with contributor avatars.

More projects