Senior Software Engineer, Backend (AI Platform)

AI Platform team

What you'll do

• Own technical decisions and projects from design through launch and on-call.
• Design and build gateway, runtime, and evaluation services to scale AI workloads securely across users and transactions.
• Build identity, quota, routing, caching, and failover controls for attributable, governable AI usage.
• Partner with security, infrastructure, and product engineering teams on agent guardrails and tool-access identity.
• Create and monitor metrics and own operational health, including monitoring, alerting, runbooks, and on-call.
• Set and improve code review and design standards and promote them through writing and technical talks.
• Use AI tools and agentic workflows in coding, design review, and operations.
• Educate and mentor engineers and promote design, coding, and testing best practices.

What we look for

• 4+ years designing, developing, and launching scaled backend systems using languages such as Python or Kotlin.
• Experience developing highly available distributed systems using technologies such as AWS, MySQL, and Kubernetes.
• Production experience building with LLMs, agents, or AI frameworks, including examples such as inference APIs, gateways, MCP, tool calling, evaluations, or agent runtimes.
• Understanding of AI usage and infrastructure for workloads across disciplines.
• Experience planning significant features or system components and creating simple, extensible designs.
• High-quality coding ability and experience changing large codebases safely.
• Ownership of professional growth and proactive feedback-seeking.
• Strong verbal and written communication for collaboration with a global engineering team.
• Equivalent practical experience or a bachelor's degree in a related field.

Workplace

• This role is remote and open to candidates residing in Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Prince Edward Island, or Saskatchewan.
• Affirm describes itself as remote-first; new hires are invited to an in-person onboarding experience.

Compensation

• Canadian base pay range is $153,000–$213,000 CAD per year.
• Total compensation may include equity rewards, monthly stipends, and benefits.

Benefits highlights

• Benefits include health coverage, spending stipends, flexible time off, holiday calendars, and an employee stock purchase plan.