DENIS IZAIAS PEREIRA · SENIOR SOFTWARE ENGINEER
For ten years I have built product interfaces. My specialty is frontend, working with React, Next.js and Vue. I also take ownership of Node.js, data, integrations, testing and deployment when the flow requires an end-to-end view.
While building my own product, DeNode, I turn real operations into software: self-service, delivery, an independent POS, local printing and fiscal integration with explicit responsibilities.
Curitiba, Brazil · working remotely
01 / TECHNICAL CASE
Self-service owns channels and operations. The POS keeps checkout, sales, inventory and fiscal concerns within its own boundary. Each product works alone; when connected, they exchange versioned events and identities.
OPERATIONAL CONTEXT
PRODUCT ARCHITECTURE
FROM DELIVERY TO SUPPORT
Products, categories, add-ons, combos, pizzas and per-channel availability.
Orders, tables, kitchen, stations, waiters, couriers and scheduled orders.
Local catalog, payments, inventory, cash register, optional kitchen and reports.
Decoupled FiscalProvider and PrintJob delivered to the local agent.
versioned contract · HMAC · nonce
→retry · idempotency · audit trail
Idempotent POS InboxThe external projection never creates catalog entries, mappings or balances automatically.
Integration is optional and disabled by default. POS downtime does not stop orders, kitchen or delivery; pending events can be replayed with a complete audit trail.
ECOSYSTEM STACK
02 / ENGINEERING DECISIONS
I map who uses the product, the task path and the systems or people required to complete it.
I define what belongs to the interface, backend or a provider, and who validates rules and changes state.
I separate temporary interaction from persistent records and preserve layer contracts, including in prototypes.
I reuse what already works, isolate variations and deliver in stages without breaking the existing product.
I verify real dependencies, failure modes, state recovery and certification before considering a flow ready.
03 / EXPERIENCE
Global payments project: Click to Pay integration between Mastercard and Cielo, Passkeys/WebAuthn, technical analysis, security and requirements certification.
Sebrae-SP Agenda with Vue, Nuxt and React: search, geolocation, filters and event journeys with UX, QA and backend teams.
Account activation and recurring payments, responsive interfaces and automated tests across critical banking flows to protect against regressions.
Architecture and evolution of Table ordering, QR Menu, Delivery and operations with Node.js APIs, PostgreSQL, real-time events and deployment.
Work on a global Mastercard project for digital payments and checkout experiences, including the Click to Pay integration between Mastercard and Cielo. Implementation and adaptation of Passkeys/WebAuthn features, API integrations, security requirements, technical analysis and certification.
Built browser-based gamified promotional experiences for acquisition, engagement and retention within the Traffic squad. Structured components, state and API integrations as a reusable foundation for new campaigns using React, Next.js, TypeScript and Zustand. Worked with UX, backend and marketing, and contributed selectively to a Nuxt 4 and shadcn/ui backoffice.
Technical leadership in the evolution of digital solutions alongside UX, QA and backend teams. Built and maintained Vue, Nuxt, React, TypeScript, Vuetify and SCSS interfaces for navigation, search, geolocation, topic filters and both in-person and online event journeys.
Developed banking features and payment flows, including account activation and recurring payments. Built responsive interfaces with Vue.js, SCSS and BEM, supported by component and critical-flow tests with Jest and Testing Library to strengthen regression protection.
Created scalable components, standardized the codebase and evolved the product-management backoffice. Worked with SSR, REST and GraphQL integrations, Vuex, Storybook and design-system practices.
Developed interfaces for digital products with a focus on user experience, intuitive navigation and reusable components. Worked within a cross-functional squad with an emphasis on clean code and continuous maintenance.
Contributed from the beginning of the project that transformed locally installed logistics software into a web application.
React, Next.js, Vue, design systems, accessibility, testing, performance and API integration.
APIs, PostgreSQL, events, authentication, Docker and delivery with JavaScript and TypeScript.
04 / CONTACT
I consider permanent roles, contractor engagements and project-based work. I want to contribute to teams that value product thinking, interface quality and technical decisions that hold up in production.
