Software Engineer (Java, C#)

About The Company Founded in 2013, Block has revolutionized the financial technology landscape with its innovative approach to increasing access to the global economy. Starting with a simple peer-to-peer payment solution, Cash App has grown into a comprehensive financial ecosystem, offering a variety of products including Afterpay/Clearpay, to enable users to send, spend, invest, borrow, and save seamlessly. With over 50 million monthly active customers, Block is committed to redefining the world's relationship with money by making financial services more relatable, instantly accessible, and universally available. The company employs thousands of professionals worldwide, fostering a culture centered around innovation, collaboration, and impact. Its distributed workforce model ensures flexibility and inclusivity, allowing employees to work remotely from various locations where Block operates, while maintaining a focus on creativity, productivity, and employee satisfaction. About The Role The Staff Software Engineer in the Financial Platform Issuing team at Block plays a pivotal role in managing and enhancing the card issuing platform that supports all Block brands, including Cash App Card, Square Card, and upcoming card programs. This team oversees the entire lifecycle of card management—from issuance, fulfillment, and activation to real-time transaction authorization, processing across card networks, digital wallet provisioning, 3-D Secure authentication, clearing, settlement, and dispute resolution. The engineer will bring deep expertise in global card networks, especially Visa, to address complex technical challenges at the network boundary. The role involves direct collaboration with card networks, influencing requirements, troubleshooting message-level issues, and building durable systems and tooling to ensure reliable, scalable, and compliant payment solutions. As a hands-on technical leader, the engineer will contribute to system design, development, certification processes, and operational excellence, working closely with cross-functional teams to deliver innovative financial products that meet rigorous standards and customer expectations. Qualifications Deep, current expertise with at least one major card network, ideally Visa, including direct connectivity, ISO 8583, authorization and clearing flows, stand-in processing, specifications, certification, and mandates.Experience building, certifying, or operating a live direct network connection, not solely through a processor.Proven track record of working directly with card networks to achieve concrete outcomes such as rulings, exceptions, configuration changes, or certification approvals.Strong hands-on software engineering experience with highly reliable financial or payments systems at scale.Experience leading complex, ambiguous projects across multiple teams and influencing technical decisions beyond immediate ownership.Ability to create durable technical leverage through frameworks, standards, tooling, or architecture that other engineers adopt.Broad understanding of the card lifecycle, including issuance, fulfillment, provisioning, activation, authorization, ledgering, clearing, settlement, reconciliation, disputes, and fraud management.Working knowledge of Mastercard and American Express, with deep expertise in at least one major network.Fluency with AI-assisted engineering workflows and sound judgment in applying AI-generated insights.Willingness to participate in on-call rotations and incident response for critical financial systems. Responsibilities Serve as a technical expert on global card networks, interpreting network specifications, message flows, certification requirements, and mandates to ensure compliance and operational excellence.Lead complex engineering challenges at the network boundary, coordinating across teams and systems to resolve issues and improve platform capabilities.Collaborate with technical leads, program owners, and senior stakeholders to develop solutions that align with network requirements and business objectives.Maintain a hands-on approach by writing production-grade code, analyzing network messages, building certification tools, and debugging protocol-level issues.Drive network certification and mandatory release cycles, translating network mandates into actionable engineering tasks and ensuring timely delivery.Establish and promote shared frameworks, standards, and tooling to make network expertise durable and scalable across teams.Mentor engineers through design reviews, code reviews, documentation, and technical guidance to elevate team capabilities.Leverage AI-powered tools throughout the development lifecycle to enhance velocity, accuracy, and operational efficiency.Take operational ownership of critical financial systems, participating in on-call duties, incident management, and continuous system improvements to ensure reliability and correctness. Benefits Comprehensive health insurance plans including medical, dental, and vision coverage.Flexible work arrangements, including remote work options.Generous paid time off and flexible leave policies to support work-life balance.Retirement savings plans with company matching contributions.Modern family planning benefits, including parental leave and fertility support.Professional development opportunities, including training, conferences, and mentorship programs.Access to cutting-edge tools and technologies to support innovative work.Inclusive and diverse workplace culture committed to equity and belonging. Equal Opportunity Block is an equal opportunity employer committed to fostering an inclusive environment for all employees and applicants. We evaluate all candidates without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, or any other legally protected status. We are dedicated to providing reasonable accommodations throughout the recruitment process for disabled applicants and those with other needs. Our goal is to build a diverse team that reflects the communities we serve and to ensure everyone has an equal opportunity to succeed and thrive at Block.