Senior Software Engineer (Comms Core)

Location: Remote Spain; Remote Poland is also listed as an available location. The role requires being based in Spain for the Spain position. Remote-first work may occasionally require in-person office work, and all new hires attend an in-person onboarding experience.

Salary: €86,000–€122,000 base pay per year.

Company

Affirm develops financial technology that enables customers to pay over time through clear and predictable payment experiences.

What you will do

• Own and deliver quarterly technical goals for the Communications area, solving ambiguous 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.
• Design, implement, and operate resilient integrations with external messaging vendors while balancing reliability, latency, cost, and compliance.
• Collaborate with product management, design, analytics, security, and engineering partners throughout the product lifecycle.
• Define service-level objectives and metrics, improve alerting and incident response, support service availability, and participate in the required on-call rotation.
• Improve design, testing, code review, rollout, and operational standards; provide mentorship, feedback, and technical direction.

Requirements

• 5+ years of software development or engineering experience, with a deep understanding of system design and architecture.
• Proficiency in modern programming languages such as Python, Kotlin, or similar.
• Experience developing highly available distributed systems using technologies such as 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 for different capabilities, rate limits, and failure modes.
• Experience defining technical plans for significant features or system components and producing elegant, simple, extensible designs and high-quality code.
• Proficiency in making significant changes in large codebases and developing tools and practices that enable safe delivery.
• Proficiency with AI-assisted development tools and sound judgment when validating their outputs.
• Demonstrated ownership of professional growth, including proactively seeking feedback.
• Strong verbal and written communication skills for collaboration with a global engineering team.

Culture and Benefits

• Remote-first work with flexibility within the country of employment.
• 100% subsidized medical coverage, including coverage for dependents, plus dental and vision benefits.
• Monthly stipends for technology, food, lifestyle, health, and wellness spending.
• Flexible time off, holiday calendars, and Away Days for rest and wellness.
• Learning and Development programs, parental benefits, Employee Resource and Community Groups, and an employee stock purchase plan.

Hiring process

• Inclusive interview process with accommodations available for candidates with disabilities.
• All new hires participate in an in-person onboarding experience.