/cv

cv

zoey

Zoey de Souza Pessanha

Senior Software Engineer | OSS Maintainer | Elixir em Foco Co-Host

Campos dos Goytacazes, Rio de Janeiro, Brazil

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Summary

Senior Software Engineer specializing in high-scale financial systems and distributed architectures using functional programming. Extensive experience with Brazilian payment methods (credit cards, PIX) and building resilient, fault-tolerant fintech platforms. Active open-source maintainer in the Elixir ecosystem, contributing developer tools and protocol implementations. Co-host of Brazil's first Elixir podcast, advocating for functional programming and community knowledge sharing.

Technical Skills

Primary Languages: Elixir, Rust, Zig, Typescript Specializations: High-Scale Financial Systems, Brazilian Payment Methods (Credit Card, PIX), Distributed Systems, MCP Architecture, Retrieval-Augmented Generation (RAG) Focus Areas: Functional Programming, Fault-Tolerant Architectures, Category Theory, Protocol Design

Professional Experience

New Generation | Software Engineer

May 2026 - June 2026 | Remote

Worked on the company's RAG, knowledge-base, and evaluation platform built with Elixir, Phoenix LiveView, Ash, Oban, and PostgreSQL/pgvector. Designed and shipped the platform's AI knowledge-base generation feature end to end: the Ash domain and database foundations, an Oban workflow orchestrating outline, research, writing, citation, and finalization stages, a source ingestion pipeline handling URL fetching, file upload, normalization, chunking, and parallel embedding, and the LiveView admin interface tying it all together. Improved retrieval accuracy with hybrid search combining lexical pg_trgm matching and vector results through reciprocal rank fusion, and built the draft review experience with per-section AI refinement, revision history, numbered citations, and full lineage tracing each generated article back to its source chunks. This work gave the company its first automated knowledge-base generation capability, with review, refine, and lineage layers making the AI output auditable and safe for production use.

Dashbit | OSS Engineer

August 2025 - December 2025 | Remote, Poland

Developed and maintained tidewave.ai, an AI-powered coding agent that helps developers build full-stack applications faster. Led implementation across multiple framework integrations including Phoenix, Rails, and JavaScript/Next.js ecosystems. Built MCP (Model Context Protocol) server implementations and architected multi-framework support for Rails and Next.js applications. Maintained core Elixir/Phoenix backend infrastructure serving the tidewave ecosystem, and contributed to Dashbit's open-source tooling for the Elixir community.

CloudWalk, Inc. | Senior Software Engineer

December 2024 - July 2025 | São Paulo, Brazil

Led the implementation of Model Context Protocol (MCP) architecture company-wide, enabling seamless integration between AI systems and financial tools. Architected and delivered the hermes-mcp SDK (313 GitHub stars), providing a high-performance MCP implementation in Elixir. Worked with multiple tech stacks including Elixir, Rust, Go, Ruby, and TypeScript to establish MCP patterns across teams. Contributed to JIM, CloudWalk's AI-powered financial assistant for Brazilian businesses.

Cumbuca | Senior Software Engineer

October 2023 - October 2024 | São Paulo, Brazil

Led development and integration of Elixir-based credit card processing systems for Brazilian payment methods, handling high-volume transactions with strict compliance requirements. Architected systems for high-availability applications processing thousands of concurrent credit card transactions. Mentored junior developers and provided strategic guidance on system architecture optimization. Implemented CI/CD pipelines and championed agile methodologies, improving team efficiency and product quality.

Nubank | Software Engineer

February 2023 - October 2023 | São Paulo, Brazil

Contributed to new features for fintech applications, focusing on user engagement and system responsiveness. Played a key role in enhancing app performance, ensuring robust, scalable solutions in a fast-paced environment. Involved in architecture and implementation of microservices for better scalability and maintainability. Collaborated with cross-functional teams to align development with strategic business goals.

Solfácil | Software Engineer

May 2021 - November 2022 | São Paulo, Brazil

Designed and implemented microservices architecture for payment processing systems handling PIX and credit card transactions at scale. Drove adoption of "explicit architecture" within the development team to streamline operations and reduce system complexities. Developed fault-tolerant backend systems processing high-volume financial transactions with minimal downtime, ensuring compliance with Brazilian payment regulations. Collaborated with product managers to align development efforts with customer needs and company goals.

Boosting.tech | Software Engineer

November 2020 - May 2021 | Campos dos Goytacazes, RJ, Brazil

Implemented robust web APIs that reduced latency and improved reliability of business-critical operations. Redesigned user interfaces, improving overall user satisfaction and engagement. Integrated modern frontend technologies to create responsive and intuitive user interfaces.

GEROS RETIFICA LIDER | Software Engineer

December 2019 - April 2020 | Campos dos Goytacazes, RJ, Brazil

Developed a service order management system to improve task efficiency and eliminate paper accumulation. Built using ReactJS, NodeJS, and ElectronJS for cross-platform desktop deployment.

Open Source Contributions

anubis-mcp - High-performance Model Context Protocol SDK in Elixir (44 stars, 195 commits). Actively maintained fork of hermes-mcp after CloudWalk discontinued maintenance. Comprehensive client/server implementations with multiple transport mechanisms (HTTP, SSE, WebSocket) and OTP-based architecture.

supabase-ex - Complete Supabase SDK for Elixir including storage-ex (Storage client), gotrue-ex (authentication), and postgrest-ex (database client). Enables full Supabase integration in Elixir applications with type-safe interfaces.

peri - Composable validation library for Elixir with schema-based validation, type safety, and comprehensive error handling. Used across multiple production applications.

exlings - Interactive learning tool for Elixir inspired by rustlings. Self-contained exercises teaching Elixir through practice, helping beginners learn the language.

Additional projects include proto_rune (AT Protocol/Bluesky SDK), nexus (CLI builder), lucide_icons, and various other Elixir developer tools. Full portfolio at github.com/zoedsoupe.

Community Engagement

Co-Host | Elixir em Foco Brazil's first podcast dedicated to the Elixir community. Explores Elixir applications across web development, embedded systems, machine learning, and more. Features discussions with professionals from complementary ecosystems (Erlang, Gleam, Clojure). Supported by the Erlang Ecosystem Foundation.

Education

Bachelor of Applied Science - Computer Science Descomplica Faculdade Digital | April 2024 - October 2026

Bachelor's Degree - Computer Science UENF - Universidade Estadual do Norte Fluminense | March 2019 - June 2022

Technical Degree - Information Technology Instituto Federal de Educação, Ciência e Tecnologia Fluminense | March 2018 - March 2020

Languages

  • Portuguese: Native
  • English: Full Professional Proficiency

Certifications

  • CS50x Certificate (Harvard's Introduction to Computer Science)
  • JavaScript (Basic) - HackerRank
  • FRONTIN Elas Programam 2023