Staff Software Engineer, Financial Platform - Issuing

Cash App, a Block company building financial products and services, is seeking a Staff Software Engineer for its Financial Platform Issuing server engineering team. The role focuses on building and operating card-issuing systems, leading complex network-boundary engineering work, managing certification cycles, and applying deep card-network expertise to improve reliability and technical capabilities.

Responsibilities:

• Be a deep technical expert on global card networks, helping Issuing teams interpret network specifications, message flows, certification requirements, mandates, and production behavior — and working directly with the networks to influence requirements, resolve ambiguity, and secure outcomes that matter for Block
• Lead complex, ambiguous engineering problems at the network boundary that span multiple teams, systems, or domains
• Partner with technical leads, program DRIs, and senior stakeholders to shape solutions where card-network requirements intersect with Block's issuing platform
• Stay deeply hands-on: write production code, build certification and conformance tooling, analyze network messages, review designs and code, and debug issues down to the protocol and field level
• Drive network certification and mandatory release cycles end to end, and translate network requirements into clear, pragmatic engineering decisions
• Establish shared frameworks, standards, tooling, and practices that make network expertise durable and enable teams to operate independently
• Raise the technical capability of engineers around you through design guidance, code reviews, mentorship, documentation, and clear technical judgment
• Apply AI-powered tools throughout the engineering lifecycle to improve velocity and quality, and help establish effective patterns for broader team use
• Share operational ownership of critical financial systems through on-call, incident response, and continuous improvements to reliability and correctness

Requirements:

• 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 mandate cycles
• Personally built, certified, or operated a live direct network connection — not only integrated through a processor
• Experience working directly with card networks to land concrete outcomes, such as rulings, exceptions, extensions, configuration changes, defect fixes, or certification outcomes
• Strong hands-on software engineering experience building and operating highly reliable financial or payments systems at scale
• A track record of leading technically complex, ambiguous work across team boundaries and influencing technical direction beyond your immediate area of ownership
• Experience creating durable technical leverage — frameworks, standards, tooling, architecture, or practices that other engineers and teams adopt
• Broad understanding of the card lifecycle, with depth in areas such as issuance and fulfillment, provisioning and activation, authorization, ledgering, clearing and settlement, reconciliation, disputes, or fraud
• Working knowledge of Mastercard and American Express, alongside deep expertise in at least one major network
• Fluency with AI-assisted engineering workflows and sound judgment in evaluating and applying AI-generated output
• Willingness to participate in an on-call rotation for critical financial systems