Senior Backend Engineer

We're building the future of preventive medicine. Molecular You analyzes blood biomarkers to help people understand their biological pathways, disease risks, and what they can actually do about it—before problems start. We work with clinicians and consumers across North America and are expanding globally.

We're a small team, which means the technical decisions you make today will be load-bearing for years. It also means you'll have real autonomy over architecture and won't spend your time getting sign-off from committees.

The Role

We seek an experienced Senior Backend Engineer to lead the design and implementation of mission-critical systems that power our platform. You will be responsible for core services including lab integrations that process thousands of biomarker results daily, analytics pipelines that generate personalized health insights, and APIs that serve web clients across multiple time zones. Your architectural decisions will directly impact our ability to scale effectively as we expand globally.

In this role, you will make strategic technical decisions that shape our platform's future. You will evaluate and recommend approaches to service architecture, determine appropriate synchronous versus asynchronous patterns, define data consistency requirements, and balance infrastructure investment with feature delivery. Beyond writing code, you will provide technical leadership by determining optimal solutions, identifying when problems can be solved without additional development, and establishing engineering best practices.

You'll spend your time:

• Designing, developing, and maintaining Ruby on Rails services for HIPAA-compliant patient data management, laboratory system integrations, and clinical recommendation engines
• Developing Elixir/Phoenix applications utilizing OTP patterns and supervision trees for high-concurrency, fault-tolerant systems requiring 24/7 reliability
• Designing and implementing event-driven architectures using RabbitMQ, including defining service boundaries, selecting appropriate consistency models, and establishing retry and error-handling strategies
• Managing production infrastructure using Terraform, including capacity planning, high-availability architecture design, and cost optimization
• Conducting thorough code reviews focused on architectural quality, system design improvements, technical debt management, and mentoring junior team members
• Working across multiple repositories at varying maturity levels, making strategic decisions regarding legacy system refactoring, service consolidation, and microservice extraction
• Collaborating with Product and UX teams in six-week ShapeUp development cycles, delivering features while managing underlying technical complexity
• Diagnosing and resolving complex distributed system issues including race conditions, message ordering problems, cascading failures, and performance bottlenecks in production environments
• Making critical technical decisions regarding database schema evolution, API versioning strategies, and infrastructure changes with significant cost and operational impact
• Participating in technical planning during cooldown periods, including technical debt assessment, infrastructure improvement initiatives, and cross-functional prioritization discussions
  

What We're Looking For

Must-haves:

• Minimum 10 years of experience designing, building, and operating production backend systems with demonstrated expertise in architecting resilient, scalable solutions
• Extensive production experience with Ruby on Rails framework, including deep understanding of Rails conventions, best practices, and when custom solutions are warranted
• Proven experience developing production applications using Elixir/Phoenix, with solid understanding of OTP patterns, concurrency models, and appropriate use cases for Elixir-based architectures
• Hands-on production experience with message queues and event-driven architectures (RabbitMQ strongly preferred), including implementing solutions for message ordering, idempotency, dead letter queue handling, and managing distributed messaging complexity
• Strong expertise in Terraform and infrastructure-as-code practices, with demonstrated ability to manage production infrastructure, handle state management, and implement reliable, maintainable infrastructure solutions
• Proven ability to make sound architectural decisions in ambiguous situations and provide data-driven justification for technical recommendations
• Strong troubleshooting skills for complex distributed systems, including request tracing across microservices, log analysis, and systematic problem diagnosis in production environments
• Demonstrated technical leadership experience including mentoring engineering team members, establishing and improving engineering practices, and influencing technical strategy
• Authorized to work in Canada

How We Work

We use ShapeUp. During six-week cycles, you're embedded with product and UX—shipping features, negotiating scope, making technical trade-offs visible. You'll have the autonomy to make calls about implementation, but you'll need to articulate the trade-offs clearly enough for non-engineers to make informed decisions.

During cooldowns, you shift to shaping: analyzing what technical problems are actually costing us, scoping infrastructure work, making the case for what engineering should prioritize. Your technical judgment will inform product direction, not just react to it.

Engineering, product, and UX work closely here. You'll have direct access to customer feedback—sometimes uncomfortably direct—and you'll be expected to balance user needs with system constraints, not just advocate for technical purity.

Our Stack

• Backend: Ruby on Rails, Elixir/Phoenix
• Message Queue: RabbitMQ
• Infrastructure: Terraform, AWS
• Database: PostgreSQL
• Version Control: GitHub
• Project Management: JIRA (we track work, not micromanage it)

What We Offer

• Significant architectural ownership and decision-making authority with direct impact on platform scalability and technical direction
• Opportunity to build systems that directly impact patient health outcomes and preventive care delivery
• Senior-level position with substantial influence over engineering culture, practices, and technical strategy in a growing organization
• Exposure to diverse technical challenges including distributed systems architecture, healthcare data compliance (HIPAA/PIPEDA), international scaling, legacy system modernization, and greenfield service development