# Mateus Lazarus

> Senior Software Engineer focused in high-scale financial applications — Senior Software Engineer with 6+ years of engineering experience, including 5 years specializing in high-scale, highly regulated financial systems. I architect resilient distributed systems that process 100M+ customer transactions daily and tens of billions in annual financial volume. For more than a year, I have worked in international teams distributed across multiple countries and time zones.

## Core Technical Profile
- language: Clojure (advanced)
- language: ClojureScript (advanced)
- language: C# (expert)
- language: JavaScript (advanced)
- language: TypeScript (advanced)
- language: Python (advanced)
- framework: .NET (expert)
- framework: Angular (intermediate)
- framework: Babashka (intermediate)
- framework: Express.js (advanced)
- framework: Next.js (intermediate)
- framework: Node.js (advanced)
- framework: React.js (intermediate)
- framework: LangGraph (intermediate)
- tool: AI — Claude Code (advanced)
- tool: AI — Gemini Enterprise Agent Platform (advanced)
- tool: AI — Agentic Workflows & MCPs (advanced)
- tool: AWS (S3, Fargate, EKS, Lambda) (advanced)
- tool: Azure (advanced)
- tool: Azure Pipeline (intermediate)
- tool: Azure Service Bus (advanced)
- tool: Cloudflare (intermediate)
- tool: Databricks (intermediate)
- tool: Datadog (advanced)
- tool: Docker (advanced)
- tool: Kubernetes (K8) (advanced)
- tool: Git (expert)
- tool: GitHub Actions (advanced)
- tool: Google BigQuery (intermediate)
- tool: Grafana Loki / Prometheus (advanced)
- tool: Grafana K6 (software testing) (intermediate)
- tool: Kafka (advanced)
- tool: MongoDB (advanced)
- tool: MySQL (advanced)
- tool: SQL Server (advanced)
- tool: New Relic (advanced)
- tool: Nginx (advanced)
- tool: Playwright (intermediate)
- tool: PostgreSQL (advanced)
- tool: RabbitMQ (intermediate)
- tool: Reqnroll (advanced)
- tool: Selenium (intermediate)
- tool: SpecFlow (advanced)
- tool: Splunk (intermediate)
- tool: Terraform (advanced)

## Canonical Resources
- [Full CV Data](/resume.json): Machine-readable JSON Resume standard.
- [Full LLM Context](/llms-full.txt): Detailed breakdown of experience, projects, and engineering decisions.
- [GitHub](https://github.com/mateus-lazarus): Source code and open-source contributions.

## Key Career Highlights
- **Nubank** (Software Engineer): Chosen as one of the people to start the new Reconciliation team inside Global Platforms and Core Banking area, responsible for all core banking flows of clearing, chargeback, fee collections, and settlement related to the card system network (Mastercard), providing accounting data of all liabilities across all countries Nubank operates in (BR, CO, MX, US) for SAP.
- **Stone Co.** (Software Engineer): Working on high-scale financial applications handling 12B+ requests annually while maintaining 99.95%+ uptime.
- **Freelance / Independent Contractor** (Software Engineer): Contributed to projects characterized by low maintenance requirements and substantial impact on fostering customer loyalty.

## Featured Projects
- **Global Core Reconciliation Platform**: Selected to help establish the Reconciliation team within Global Platforms and Core Banking, creating a platform that governs Mastercard clearing, chargebacks, fee collections, and settlement across BR, CO, MX, and the US. The platform processes 100M+ customer transactions daily, generates 400M+ accounting entries, and reduced annual financial exposure from approximately USD 240M to less than USD 12K. Its creation now gives FP&A and Controllership near-real-time financial information that powers the company's publicly reported balances and executive decision-making.
- **Credit Product Platform**: Helped scale Stone's credit portfolio from zero to R$1B in three years by shaping requirements and building the core platform for products including Working Capital and Short-Term Credit. The platform expanded capacity from 10K to 1M+ requests per day while sustaining 99.95%+ uptime, enabling reliable portfolio growth and end-to-end visibility into the customer journey through JPDEX monitoring.
- **Short Term Credit Management**: Helped build the platform that enables Stone customers to obtain short-term credit in under 2 minutes and manages R$50M+ automatically across origination, approval, repayment, and risk. The platform sustains 99.95%+ uptime, supporting a fast and dependable credit experience at scale.