Senior Software Engineer, Backend (AI Platform)

Description

The company lets people pay over time in a clear, predictable way, with no hidden fees and no surprises.

The engineering team is building large-scale, fault-tolerant, global infrastructure shared by several financial products, merchants, and vendors. Every engineer needs open access to that infrastructure, which is central to the business. Engineers here write blameless postmortems and detailed tech specs, and collect feedback before major system changes.

The AI Platform team builds the standard route for creating, running, evaluating, and governing AI systems. Its users are every engineer and a growing number of production workloads. The team provides simple, governed access to models, tools, and agents, with identity, cost tracking, reliability, and security included. Its components include an LLM Gateway for all approved models (Claude, ChatGPT, and open-weight models on AWS Bedrock and other providers), an MCP Gateway that controls and logs tool calls, an Agent Runtime with bounded execution for agents, and an evaluation and observability layer that shows whether an AI change is better, cheaper, or safe to release. The platform is early: the gateway is used daily across engineering, the first production agent is live, and the coming year moves the work from developer productivity toward production inference and agents.

Responsibilities

• Own technical decisions and projects in the AI Platform team, from design through launch and on-call.
• Design and build the gateway, runtime, and evaluation services that move AI workloads at the company from pilot to production, scaling securely to millions of users and their transactions.
• Make AI spending traceable and controllable by building identity, quota, routing, caching, and failover features, so teams can adopt new models and tools without solving the same platform problems again.
• Work with security, infrastructure, and product engineering to set guardrails for agent workloads and the on-behalf-of identity model for tool access.
• Define and track metrics for your team's systems, and keep what you ship healthy through monitoring, alerting, runbooks, and on-call work.
• Set and raise code review and design standards, and promote them beyond your team through writing and tech talks.
• Use AI tools and agentic workflows daily to speed up your coding, design reviews, and operations, and push the team on what a small AI-native group can deliver.
• Coach and grow engineers on the team, and lead practices for design, coding, and testing.

Requirements

• You have 4+ years of experience designing, building, and launching large-scale backend systems in languages such as Python or Kotlin.
• You have a record of building highly available distributed systems with technologies such as AWS, MySQL, and Kubernetes.
• You have hands-on production experience with LLMs, agents, or AI frameworks, such as inference APIs, LLM gateways (LiteLLM or similar), MCP, tool calling, evals, or agent runtimes.
• You understand how AI is used and what infrastructure is needed to support AI workloads across different disciplines.
• You have planned the delivery of a significant feature or system component with a simple, elegant, extensible design. You write high-quality code that others can easily read and use.
• You can make large changes to a big codebase safely, using tools and practices you have built or refined.
• You take ownership of your growth and actively ask your team, manager, and stakeholders for feedback.
• You communicate well in writing and speech, and collaborate effectively with a global engineering team.
• You have equivalent practical experience or a Bachelor's degree in a related field.
• This remote role is open only to candidates living in Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Prince Edward Island, or Saskatchewan.

Conditions

Equity grade: 6

New hires usually start near the bottom of the pay range. Pay is set using location, experience, and job skills, aiming for a simple and transparent structure.

Base pay is part of total compensation, which may also include equity, monthly health, wellness, and tech stipends, and benefits. Medical, dental, and vision coverage is 100% subsidized for you and your dependents.

Base pay range: $153,000 - $213,000 CAD per year

LI-Remote

Remote-first: most roles can be done from almost anywhere in the country of employment. Some roles may occasionally need in-person work at an office, and a few are office-based. All new hires are invited to an in-person onboarding.

Interview accommodations are available, and for roles in San Francisco or Los Angeles, applicants with arrest and conviction records are considered as required by law.

Benefits

• Health coverage at no cost: the company pays 100% of premiums for employees and their dependents.
• Monthly stipends for tech setup and for health and wellness choices that suit you.
• Flexible time off and a generous holiday calendar.
• Employee stock purchase plan (ESPP) to buy company stock at a discount.