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Senior Software Engineer, Backend (Comms Core)

Affirm· Financial Platforms - Engineering
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Hybrid (Spain)Full-timePosted 5d ago

About the role

Senior backend engineer focused on the Communications platform, shaping multi-region, multi-tenant infrastructure, APIs, and vendor integrations to enable scalable customer messaging across the product lifecycle.

Responsibilities

  • Own and deliver quarterly technical goals for the Communications area, collaborating with teammates to solve ambiguous, open-ended problems across messaging infrastructure.
  • Design and evolve reliable backend services for high-volume communications across multi-region, multi-tenant environments, including orchestration, delivery, preferences, templates, and observability.
  • Collaborate with product management, design, analytics, security, and engineering partners throughout the product lifecycle, articulating technical constraints and balancing customer impact, risks, and trade-offs.
  • Design, implement, and operate resilient integrations with external messaging vendors, balancing reliability, latency, cost, and compliance.
  • Proactively identify and solve project, process, technology, or business issues that affect scalability, developer experience, and operational resilience.
  • Support the operations and availability of your team’s services by defining service-level objectives and metrics, improving alerting and incident response, and participating in on-call efforts.
  • Foster quality and ownership by improving design, testing, code review, rollout, and operational standards, and advocating for them through writing and tech talks.
  • Help develop talent on your team by providing feedback, mentorship, and technical direction, and leading by example.
  • On-Call Rotation - There would be an on-call rotation for this role as a requirement.

Qualifications

  • 5+ years of experience in software development or engineering, with a deep understanding of system design and architecture.
  • Proficiency in modern programming languages such as Python, Kotlin, or similar.
  • Track record of developing highly available distributed systems using technologies like AWS, MySQL, DynamoDB, and Kubernetes.
  • Experience designing multi-region, multi-tenant platforms with strong isolation, scalability, failure recovery, and data-consistency guarantees.
  • Experience integrating with third-party communications or messaging vendors and designing abstractions that account for different capabilities, rate limits, and failure modes.
  • Experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple and extensible design.
  • Ability to write high quality code that is easily understood and used by others.
  • Proficiency with making significant changes in a large code base, and developing a suite of tools and practices to do so safely.
  • Proficiency with AI-assisted development tools and applying sound judgment to validate outputs.
  • Demonstrated ownership of growth, proactively seeking feedback from team, manager, and stakeholders.
  • Strong verbal and written communication skills for effective collaboration with a global engineering team.

Skills

Required:Software architecture and system designPythonDistributed systemsAWS
Nice to have:Kotlin

Benefits

  • Flexible Spending Wallets for tech, food and lifestyle
  • Away Days - wellness days to take off work and recharge
  • Learning & Development programs
  • Parental benefits
  • Employee Resource & Community Groups
  • 100% subsidized medical coverage, dental and vision for you and dependents
  • Equity rewards through Affirm equity program
  • ESP base pay range per year: €86,000 - €122,000
Last updated Oct 21, 2026. Interested? Apply on the company site.

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