Founding Engineer

About the Role Join an early-stage fintech team to build backend systems for financial integrations, workflow orchestration, and ledger foundations. You will work closely with founders and early customers, helping shape product direction and engineering practices through rapid prototyping and measurable outcomes. What You'll Do Design, build, and operate backend services and public APIs for customers and partners. Develop integrations with ERP systems, banks, and financial document and file sources. Build ETL pipelines with data quality controls, validation, and reconciliation. Establish observability and operational practices, including logging, metrics, alerts, incident response, and on-call readiness. Collaborate with founders and customers to identify problems, prototype solutions, measure impact, and decide what to build or retire. Apply LLMs where they can deliver measurable value, with appropriate production guardrails. Document architectural decisions and improve engineering quality, testing, and security practices. What We're Looking For At least 5 years of backend engineering experience delivering and owning production systems end to end. Strong experience with OLTP systems, relational data modeling, REST APIs, transactional data, and consistency and availability trade-offs. Experience integrating complex external APIs, including authentication, rate limits, retries, and webhooks; financial or ERP integrations are especially relevant. Ability to extract, validate, and normalize data from sources such as PDFs, XML, and email. Practical cloud and DevOps skills, including AWS or GCP, Docker, CI/CD, and production logging and monitoring. Experience with ETL, data quality, reconciliation, and operational excellence. Familiarity with accounting and ledgers, including double-entry bookkeeping and journal entries, is beneficial. Experience with event-driven systems, workflow engines, and production LLM deployments is a plus. Fintech or B2B SaaS experience, founding-engineer experience, and basic React or Next.js skills are helpful. Comfort working with ambiguity, shifting priorities, and incomplete specifications. Compensation & Benefits Base salary range: $45,000 to $80,000 USD annually. Visa sponsorship is not available. Location Hybrid role based in São Paulo, Brazil.