Open to opportunities

Willian Monteiro

@willianmonteiro

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Senior software engineer building scalable full-stack and AI-powered systems with a product-first mindset.

Brazil

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What I'm looking for

I’m looking for a long-term remote role where I can combine engineering execution with product thinking—owning sprints, collaborating cross-functionally, and building scalable systems (including AI/RAG and real-time features) from idea to delivery.

I’m a Senior Software Engineer with 8+ years building high-performance, scalable full-stack applications across agtech, water resources, pharma, and environmental tech—often in remote roles with US-based startups.

My core stack centers on React, TypeScript, Node.js, NestJS, and AWS, and I’ve built AI-powered pipelines using RAG approaches, Amazon Bedrock, and pgvector. I also bring hands-on experience with real-time systems and WebSockets.

Highlights include a 20x calculation-speed improvement via Web Workers, binary search, and Map-based caching (plus a 96.7% execution time reduction), and fixing an AI pipeline memory leak by refactoring WebSocket connection management—scaling processing from ~120 to 4,000+ components per file. I’ve also reduced PR build time by 40% through CircleCI parallelization and eliminated map freezes by moving from DOM markers to GeoJSON layers rendered on WebGL.

As a Tech Lead, I’ve led teams (7 engineers), owned sprint organization and backlog prioritization, and supported architecture decisions through code reviews and collaboration in Scrum environments. I’m looking for a long-term remote role where engineering and product thinking go hand in hand.

Experience

Work history, roles, and key accomplishments

Current

Tech Lead / Software Engineer

Current

Circa

Dec 2023 - Present (2 years 7 months)

Led a team of 7 engineers with sprint organization, backlog prioritization, code reviews, and architecture decisions. Built a real-time collaboration system with WebSockets/React Flow and architected an AI-powered RAG-based BOM matching system using Amazon Bedrock and PostgreSQL (pgvector).

Software Engineer

Syngenta - Cropwise Financials

Dec 2022 - Nov 2024 (1 year 11 months)

Resolved performance issues in a deeply nested React tree by implementing scroll-based pagination and list virtualization. Eliminated map freezes by migrating to GeoJSON layers rendered on a WebGL canvas, and contributed to a NestJS/PostgreSQL revenue attribution engine.

React React Window ResizeObserver GeoJSON WebGL NestJS PostgreSQL CircleCi CI CD SQL Cypress React Testing Library SonarQube Docker TypeScript TypeORM

Frontend Lead Engineer

Fractal

Dec 2020 - Nov 2023 (2 years 11 months)

Led an AngularJS to React migration using a micro-frontend architecture with Single-SPA across five applications. Optimized a client-side water balance calculation engine using Web Workers, binary search, and Map-based caching, and implemented PWA capabilities with Workbox.

AngularJS React TypeScript Binary Search Map Based Caching PWA Workbox Jest Cypress Bitbucket Pipelines Leadership Scrum React Testing Library React Query Frontend Architecture

Frontend Engineer

Nexfar

Dec 2019 - Jun 2021 (1 year 6 months)

Led the migration from Vue to React for a large B2B pharmaceutical platform serving 50,000+ pharmacies.

React TypeScript Redux JavaScript Scrum Docker

Web Developer

ZHF

Dec 2016 - Feb 2020 (3 years 2 months)

Developed e-commerces, Single Page Applications (SPAs), WordPress themes, and plugins using PHP, JavaScript, HTML, CSS, and SQL, with emphasis on responsive design, usability, and SEO optimization.