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Staff Software Engineer, Payments Acquiring

Block· 10414 Engineering - Fintech Platform
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Hybrid (Bay Area, CA)full-timePosted 1w ago

About the role

Staff Software Engineer on the Acquiring team responsible for the card payments acquiring stack supporting Square, Cash App, and Afterpay. Builds and operators direct network connections with card networks and acquirers, ships production-grade payment system capabilities, and leads complex technical initiatives at Block scale.

Responsibilities

  • Bring deep card acceptance expertise to the team, reading network specifications, ISO 8583 messages, mandates, and interchange rules, and turning them into sound engineering decisions.
  • Own the technical direction of your projects from design through production rollout, and lead the engineers working on them.
  • Partner with technical leads, product and finance operations partners, and stakeholders across Square, Cash App, and Afterpay to shape solutions where card-network requirements intersect with Block's acquiring platform.
  • Stay deeply hands-on: write production code, build testing and certification tooling, analyze network messages, review designs and code, and debug issues down to the protocol and field level.
  • Make and defend the technical calls on routing, retries, and processing cost, backed by data on authorization rates and fees.
  • Establish shared frameworks, standards, tooling, and practices that make payments expertise durable so the team makes good payments decisions without routing every question through you.
  • Raise the technical capability of engineers around you through design guidance, code reviews, mentorship, documentation, and clear technical judgment.
  • Build with AI agents across the engineering lifecycle, and help set the patterns for using them safely on systems that move money.
  • Share operational ownership of critical financial systems through on-call, incident response, and continuous improvements to reliability and correctness.

Qualifications

  • Deep card payments experience at the message level: integrations that talk to networks, acquirers, or processors (ISO 8583 or an acquirer's host format)
  • Acquiring or merchant-side experience is ideal, and a direct network connection is a strong plus. ISO 20022 is a plus.
  • Experience with hard cases in real card transactions (partial and incremental authorizations, reversals, tips, currency conversion, interchange qualification).
  • Strong hands-on software engineering experience building and operating highly reliable financial or payments systems at scale, with design review, automated testing, and safe rollouts.
  • Track record of leading technically complex projects from design through delivery and setting technical direction.
  • Experience creating durable technical leverage — frameworks, standards, tooling, architecture, or practices that other engineers adopt.
  • Broad understanding of end-to-end card payment flow, including card data security and tokenization, routing, authorization, capture, clearing and settlement, reconciliation, interchange and processing costs, or chargebacks.
  • Solid understanding of card network rules (Visa, Mastercard, AmEx, Discover, US debit) and the roles of acquirers, processors, payment facilitators, sponsor banks.
  • Daily experience building with AI coding agents and good judgment about when outputs are correct.
  • Willingness to participate in an on-call rotation for critical financial systems.

Skills

Required:Card payment network integration (ISO 8583/host formats)End-to-end payments lifecycleSoftware engineering leadershipOn-call reliability and incident response

Benefits

  • Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning (as part of the offering).
Last updated Oct 14, 2026. Interested? Apply on the company site.
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About Block

Block builds technology to increase access to the global economy.

Made up of Square, Cash App, Afterpay, TIDAL, Bitkey, and Proto, Block, Inc. builds technology to increase access to the global economy.

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