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Ivonei Junior
Resume

Ivonei Junior

Full-stack & AI Engineer / Consultant · Healthtech

ivoneijr@gmail.comGitHubLinkedIn

Profile

Technology Consultant & Entrepreneur with 20+ years in the IT industry and 13 years building software, creating real, scalable, and high-impact products end to end. JavaScript/TypeScript expert with strong experience across the entire ecosystem. Also worked with Java, Ruby, Python, and Golang. Proven ability to drive complex projects from architecture through implementation.

Since 2020, I've been operating as an independent consultant and entrepreneur, working directly with global brands and innovative startups. I've delivered solutions for companies such as Cisco, Amazon, Intel, NASCAR, and BeachBody, working on high-complexity, high-visibility projects. I'm also an active open-source contributor — including a feature in LangChain used by thousands of developers worldwide.

Beyond hands-on engineering, I've acted as a founding engineer, aligned closely with C-level executives, and led multiple teams simultaneously. I thrive in fast-paced environments where business clarity, technical excellence, and ownership truly matter.

I'm also experienced with Java, Ruby, Python, and Go, and can quickly adapt to any technical ecosystem.

Full-stack & AI Consulting

Independent Technology Consultant & Entrepreneur — Jan 2020 – Present

Since 2020, I've been operating as an independent consultant and entrepreneur, working directly with clients ranging from Fortune 500 companies to innovative startups. I deliver end-to-end solutions, from architecture and strategy to full implementation, helping clients build scalable, high-impact products.

Client: Turing (US HealthTech)

Jan 2025 – Present

Staff-level full-stack engineer for a confidential US healthtech building a medical-grade in-ear wearable for continuous health monitoring, with tightly integrated mobile, firmware, and cloud components. I own the architecture and delivery of a large part of the member-facing and operational platform on AWS, from identity and billing to internal support tooling, and set the engineering standards the team builds on. I work autonomously: I run my own research and hold regular conversations with people across teams to align my work with the company's goals, then create, manage, and maintain the resulting projects end to end, keeping stakeholders informed with frequent status updates.

Key deliverables:

  • Privacy-by-design data boundary: worked within an architecture that isolates personal and billing data from health telemetry, and built the controlled bridge between them, so support staff can inspect device telemetry without ever being exposed to personal identifiers.
  • Serverless backend: evolved a REST API on AWS Lambda that handles API Gateway, RPC, and IoT Core (MQTT) events, backed by PostgreSQL/Prisma, Cognito, KMS, DynamoDB, S3, and Secrets Manager. Delivered device claiming and cloud assignment, IoT pairing, and automatic firmware-cohort rollout (Memfault) on assignment.
  • Subscriptions & payments: built membership on Stripe subscription schedules (entitlements modeled as phases): one-click subscribe with a saved card, plan changes, cancellation with reason capture, and reactivation.
  • Member portal: passwordless email-OTP sign-in and an 8-step onboarding wizard from email to plan choice and payment, plus a full visual redesign.
  • Internal support platform, largely built from scratch: 360° member profile, battery and signal-quality telemetry charts, mobile analytics event history (PostHog) with maps, Cognito role-based access control with anti-lockout safeguards, device-assignment tool, alpha-readiness checker, firmware release-notes editor, audited activity timeline, and a KPI dashboard.
  • Shared platform & observability: a cross-app design system (shadcn + Storybook) that replaced duplicated components, a PII-redacting Sentry + OpenTelemetry package, and a LaunchDarkly feature-flag registry with segment sync.
  • Security & platform health: hardened session isolation and caching behavior at the edge, and led a staged decommissioning of legacy code (an EventBridge jobs subsystem, a checkout pipeline, dozens of unused routes, and 10+ database tables) through Prisma migrations with zero downtime.
  • Engineering standards: CI quality gates (Biome, PR coverage reports), documented web-app architecture conventions (feature slices, React Query, Zustand, react-hook-form + zod), a living knowledge base, and AI-agent tooling (Claude Code skills, hooks, and CI checks) adopted by the team.

Client: Booksopen.io (Senior Software Engineer)

Jan 2024 – Dec 2024

Worked at staff engineering level on the 0-to-1 build of a startup in the body-transformation industry, working directly with C-level to define business direction and technical strategy.

  • Planned and built the entire MVP, including a complex scheduling system for professionals.
  • Designed the backend with NestJS, PostgreSQL, Prisma, Bull, and deployed it on Heroku.
  • Delivered the frontend using Next.js and managed deployments with AWS Amplify.
  • Helped the team grow, improved engineering practices, and set technical standards.

Client: Productbot AI

Jan 2023 – Jan 2024

Consulted on building a full SaaS platform from scratch in six months, focused on generative AI workflows.

  • Designed and implemented RAG pipelines and intelligent agents with LangChain.
  • Contributed to the LangChain OSS project with a new LLM wrapper enabling streaming for private models on AWS SageMaker + LLaMA2.
  • Worked with custom/self-hosted LLMs and advanced AI chain orchestration.

Client: X-Team / BeachBody

Jul 2021 – Dec 2022

Provided consulting services for multiple projects, including enterprise-scale serverless architecture.

  • Built scalable serverless architecture for BeachBody using AWS Lambda, Node.js, and TypeScript.
  • Fullstack consulting for MadeRenovation: React, Node, GraphQL, Prisma, Algolia.
  • Led major refactors improving maintainability and long-term performance.
  • Contributed to XHQ, an internal X-Team tool.

Client: Dentsu World Services

Jan 2020 – Jul 2021

Led full-stack innovation projects as a consultant for global brands like Intel, Amazon, Cisco, and NASCAR.

  • Delivered solutions ranging from 3D applications to high-performance backend systems.
  • Highlight projects:
    • Ally Racing web game (Node, Lambda, DynamoDB)
    • Intel 3D web application (React, Three.js, A-frame)
    • Confidential Electron-based desktop app for Cisco
    • Amazon Local Selling 3D product showcase
  • Mentored engineering teams and contributed to career reviews and skill development.

Early Career

Software Engineering Roles — 2013 – 2019

Software Engineer — 4all (Iris Data Driven)

2019 – 2020

  • Led backend (Node, GraphQL) and frontend (React) for a large-scale Customer Data Platform.
  • Collaborated with QA to ensure data accuracy and reliability.

Software Engineer — Rocketlab (Sydney)

2018 – 2019

  • Built high-quality web and mobile apps with strong UX and maintainability concerns.
  • Backend with Node + GraphQL + serverless.
  • Component architecture using Storybook and styled-components.

Founding Engineer — Triider

2017 – 2018

  • Co-founded and served as founding engineer of a startup that was later acquired for several million dollars.
  • Engineered end-to-end web and mobile platforms connecting customers with service providers across multiple verticals.
  • Built core marketplace functionality including matching algorithms, real-time notifications, and service provider management systems.
  • Integrated payment gateways and implemented secure transaction processing.
  • Designed and deployed scalable AWS infrastructure supporting rapid growth.
  • Tech stack: Node.js, Angular, React, Redux for frontend and backend development.

Software Engineer — 4all / Soccer Team

2017 – 2018

  • Member of the dedicated soccer team responsible for creating official web and mobile solutions for major Brazilian football clubs.
  • Architected and developed fullstack solutions using Node.js, React, Redux, and Immutable.js for state management.
  • Built official club platforms including fan engagement features, match information systems, and ticketing integrations.
  • Developed and maintained React Native mobile applications for major soccer teams including Grêmio and Internacional.
  • Established a strong testing culture using Jest, Cucumber, and Nightmare for end-to-end testing, ensuring high-quality deliverables for high-profile clients.

Software Engineer — Zallpy (Edenred)

2016 – 2017

  • Fullstack engineer on the Edenred B2B Parts platform, an automotive parts auction system connecting suppliers and insurance companies.
  • Built and maintained core auction functionality, bidding systems, and real-time transaction processing using Ruby on Rails.
  • Integrated REST and SOAP APIs for seamless communication with external partners and suppliers.
  • Migrated the frontend from Rails views to a modern React application, improving user experience and performance.
  • Deployed and managed infrastructure on AWS, ensuring high availability and scalability for enterprise clients.

Software Engineer — Zeta Informática

2014 – 2016

  • Led the modernization of a legacy system from CLERIUM (proprietary language) to a modern web architecture using Ruby on Rails, Angular, and Node.js.
  • Architected and implemented migration strategies, ensuring zero downtime and data integrity throughout the transition.
  • Maintained and enhanced a critical fiscal document integration system connecting with official Brazilian government tax systems.
  • Developed migration scripts, implemented OAuth2 (RFC6749) authentication, and built middleware solutions similar to GraphQL for API orchestration.
  • Maintained ERP systems and various internal tools supporting business operations.

Intern — Procempa (Government Agency)

2013 – 2014

  • Initiated new projects using Java and Hibernate, building robust data persistence layers for government systems.
  • Integrated reporting tools and business intelligence solutions to support decision-making across multiple departments.
  • Participated in strategic planning meetings with various government offices to define requirements and scope new projects.
  • Modernized public inquiry and appointment-scheduling systems, improving citizen access to government services.

Notable Achievements

  • Independent Consultant & Entrepreneur — Operating successfully since 2020, working with Fortune 500 companies and innovative startups.
  • University recommendation letter for academic contributions.
  • Led 3 engineering teams simultaneously across multiple client engagements.
  • Migrated monolithic architecture to microservices for enterprise clients.
  • Founding engineer at Triider, which was successfully acquired for several million dollars.
  • Contributed to an Intel project nominated for global marketing awards.
  • Added streaming capability to LangChain for private LLMs (SageMaker).
  • Multiple OSS contributions.
  • Creator of ProfileHub AI, a platform that uses generative AI to enhance recruitment by turning resumes into interactive, queryable candidate profiles.

Education

  • MBA in Artificial Intelligence and Data Science in Healthcare, PUCRS — 2026 – Present (in progress)
  • Bachelor's in Philosophy, UNINTER — 2020
  • Systems Analysis and Development, SENACRS — 2017
  • Bachelor’s in Information Systems, PUCRS — 2013

References

Many references available upon request.