Mateus Lazarus

Senior Full-Stack Product Engineer

📧 [email protected] | 📍 São Paulo, Brazil

Open to Relocation to London, UK / Skilled Worker Visa

GitHub |LinkedIn |Website

Specialized Risk & Credit Analysis Platform at Stone Co.

stone.com.br

Led and built an internal web platform for risk analysts using Next.js, TypeScript, and Google Scripts to streamline complex business registration and risk assessment workflows.

• Reduced a tedious 10-page, 40-minute manual process by 50%, drastically improving operational agility, user satisfaction, and eliminating human data-entry errors.
• Modernized Stone's core risk analysis infrastructure, replacing a legacy monolith with scalable microservices supporting high-value assessments exceeding R$20M (~USD 5M) per evaluation.

Global Core Reconciliation & Operations Platform at Nubank

Architected and scaled the global reconciliation platform governing Mastercard clearing, settlement, chargebacks, and fee collections across BR, CO, MX, and US, processing 100M+ customer transactions daily.

• Improved platform accuracy to reduce annual financial exposure from ~USD 240M to under USD 12K within 12 months, providing executive leadership with near-real-time balances.
• Spearheaded company-wide AI adoption by authoring internal AI Model Context Protocol (MCP) guides (+3,350 users, +10,000 views) and hosting hackathons, raising business unit AI engagement from 33% to 86%.

Credit Product Platform & Short-Term Credit at Stone Co.

stone.com.br/capital-de-giro stone.com.br/limite-da-conta

Built and scaled core credit systems from scratch to R$1B+ in portfolio value, increasing capacity from 10K to 1M+ requests per day while maintaining 99.95%+ uptime.

• Engineered automated approval and repayment pipelines managing R$50M+ in short-term credit, delivering sub-2-minute customer approvals.

• Co-founded the Reconciliation team within Global Platforms & Core Banking, operating in an English-first, async international team across 4+ time zones.
• Led the end-to-end discovery and architecture for expanding reconciliation pipelines to support global debit products, collaborating directly with cross-functional stakeholders across four countries.
• Re-engineered 2 legacy services processing 100M+ daily transactions, achieving 100% observability, refactoring model designs, and enabling automated, real-time tracking of core operational KPIs.
• Accelerated engineering throughput across the team to 6–8 PRs per engineer weekly with <1 day review turnaround time by optimizing development workflows.

• Architected high-scale full-stack applications and microservices handling 12B+ annual requests while maintaining 99.95%+ uptime and >95% unit test coverage.
• Designed and launched an internal Next.js/TypeScript application for risk analysts, turning a complex 10-page manual workflow into a streamlined UI that cut processing time by 50% and removed user errors.
• Provisioned and managed cloud infrastructure using Terraform, Docker, and Kubernetes, implementing CI/CD pipelines via GitHub Actions and Azure Pipelines.
• Integrated observability, logging, and data analytics solutions utilizing Datadog, Grafana, Splunk, and Google BigQuery.

• Delivered bespoke full-stack web platforms using Node.js, TypeScript, React, Express, and PostgreSQL/MySQL for commercial clients.
• Built end-to-end CRM and access control systems for Atenas Fit, automating membership monitoring, entry security, and unpaid customer tracking to improve retention and operational efficiency.

Bachelor of Science in Computer Science

Universidade Estácio de Sá · 2022-01 — 2025-12

• GPA: 9.6 / 10.0