Senior Software Engineer - Payment Processing

About the role

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Software Engineer - Payment Processing based in Brazil.

We are seeking an experienced Senior Software Engineer to help modernize and scale a critical payment processing platform. In this role, you will tackle complex engineering challenges involving transaction tracking, financial reconciliation, fraud detection, and payment operations. You will design and implement automated solutions to replace manual processes while improving system reliability, security, and performance. Working across multiple integrations and interconnected platforms, you will help build a more unified and scalable payments architecture. You will collaborate with experienced engineering teams to address technical debt and strengthen core transaction-processing capabilities. This is an opportunity to make a significant impact on a growing payments ecosystem within a collaborative, remote-first environment.

Accountabilities: -

Design and implement automated, end-to-end transaction lifecycle tracking to replace existing manual reconciliation processes.

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Develop and enhance payment processing capabilities, including automated reconciliation, fraud detection, chargeback management, and other payment-related functions.

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Work across two parallel versions of the payment processing engine and their respective third-party processor integrations to identify and resolve inconsistencies, mismatches, and reconciliation gaps.

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Collaborate with the Storefront engineering team to improve data accessibility and establish the integrations required to close reconciliation gaps.

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Strengthen system reliability, maintainability, and scalability, ensuring the stability of critical payment flows as transaction volumes increase.

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Contribute to the design and development of a shared payments architecture connecting the payment processing engine, storefront, and events platform.

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Navigate complex, undocumented, multi-repository codebases using AI-assisted development tools such as Claude Code, Codex, or equivalent solutions.

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Make independent backend architecture decisions, evaluating service boundaries, data models, and system design trade-offs.

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Implement robust testing, monitoring, and observability practices to improve system quality and operational performance.

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Collaborate with engineering stakeholders to modernize legacy components and support the long-term evolution of the payments platform.

Requirements:

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8+ years of professional software engineering experience, with strong expertise in backend development.

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Previous experience working with financial reconciliation, ledger systems, fraud detection, transaction processing, or other payment-related technologies.