Looking for a job

Leonardo Steil

@leonardosteil

Message

I build resilient payment platforms, 3DS integrations, refund engines, and card-scheme compliance systems in PHP.

Brazil

Message

What I'm looking for

I'm looking to build reliable, high-impact backend and payments systems where clean architecture, automated testing, and disciplined AI-assisted engineering improve delivery.

At EBANX, I build and evolve payment systems spanning 3D Secure integrations, card-scheme mandates, acquirer APIs, refunds, chargebacks, and reconciliation. I led a production 3DS provider integration, built tracing with Rollbar, and created OpenSearch dashboards for complex transaction flows.

I also designed an event-driven refund retry engine that reduced manual refund intervention by approximately 70%, and a middleware framework that cut new partner integration effort by roughly 60%. Across PHP 8, Laravel, TypeScript, SQL, DynamoDB, and testing practices, I focus on explicit domain logic, reliable integrations, and maintainable architecture.

Experience

Work history, roles, and key accomplishments

Current

Senior Backend Engineer

Current

Objective Solutions

Dec 2021 - Present (4 years 9 months)

Currently on the Card Performance squad, leading development of a new Brand Mandate system with retry rules and compliance logic for card schemes. Led end-to-end integration of a new 3DS provider and designed an event-driven refund retry engine that reduced manual interventions by approximately 70%.

TypeScript PHPUnit Composer Docker GitHub Rollbar DynamoDB OpenSearch Clean Architecture SOLID Code Review Pair Programming

Backend Engineer

PipeRun Sales CRM

Sep 2019 - Dec 2021 (2 years 3 months)

Designed and maintained the product's REST API using Laravel, implemented OAuth2.0 authentication with JWT, and built an ETL pipeline for migrating customers from competing CRMs. Led the backend for a new sales reporting module.

PHP Laravel Yii MySQL PHPUnit Git

Full Stack Developer (Intern)

Conplan Sistemas de Informática

Jan 2018 - Sep 2019 (1 year 8 months)

Designed and built a configurable reporting engine for occupational health documents using HTML, CSS, JavaScript and jQuery. Helped migrate version control from SVN to GitHub and championed GitHub Actions adoption.

PHP MySQL JavaScript jQuery HTML CSS GitHub

Teaching & Research Fellow (PET-SI)

Federal University of Santa Maria

Jun 2016 - Dec 2018 (2 years 6 months)

Selected for a Brazilian Ministry of Education program with 20 hours per week of teaching, research, and outreach. Co-authored 5 published academic papers and volunteered teaching basic computer skills to children and teenagers.