Senior Backend Engineer

### Who you are
- 6+ years of backend engineering experience, ideally in consumer apps, mobile, or SaaS, with at least 2 years in a senior-level role
- Expert-level proficiency in Ruby on Rails, including modern versions and best practices (this is central to the role)
- Hands-on production experience with PostgreSQL, including schema design, indexing strategies, query optimization, and performance tuning
- Strong expertise with Sidekiq for background job processing, including scheduling, throttling, batching, and reliability patterns
- Proficiency using Redis for caching, job queues, and distributed locking
- Experience with DynamoDB or comparable NoSQL databases
- Solid background in API design, RESTful principles, versioning, and serialization
- Proven track record of integrating with third-party APIs and external services
- Experience designing, building, and scaling distributed systems in production
- Familiarity with AWS services, including S3, DynamoDB, SQS, CloudWatch, and SES
- Strong skills in testing, CI/CD pipelines, logging/monitoring, debugging, and performance optimization
- Ability to work in a fast-moving remote startup environment
- Experience building and supporting backends for mobile apps
- Experience creating internal tools or admin panels with ActiveAdmin
- Hands-on work with Shoryuken for SQS message processing
- Experience integrating payment processors like Stripe
- Event-driven or streaming architecture
- AI-assisted/AI agentic development (GitHub Copilot, Cursor, Claude Code, Codex, etc.)
- Feature flagging, experimentation, or A/B testing
- Accountable: You take ownership of your responsibilities, demonstrating trustworthiness and self-discipline. You are consistent in your work, transparent in your actions, and communicate effectively. You follow through on commitments and strive for continuous improvement
- Action-driven: Identify what is most important, agree on scope, execute in a timely manner, and drive the greatest impact. You take initiative, roll up your sleeves, and get things done
- Caring: You genuinely care about yourself and others, our business and craft, our mission and vision, and are passionate in heart and mind. You understand the importance of our team and strive to create a positive, supportive work environment
- Curious: You focus on the ‘why,’ learn and expand your knowledge, explore new ideas, and generally make things better. You're a lifelong learner with a thirst for knowledge and a constant desire to improve
- Thorough: Your work is thoughtful, impactful, timely, accurate, and complete. You pay attention to detail, are meticulous, and ensure quality work and compliance
- Take ownership and deliver reliably
- Quickly pick up unfamiliar technologies and move between systems
- Think beyond the code and care about product outcomes
- Communicate clearly, asynchronously, and proactively
- Value craftsmanship, testing, and system reliability
- Enjoy learning, improving, and making things better over time

### What the job involves
- We’re looking for an exceptional Sr. Backend Engineer to help build, scale, and evolve the backend systems powering the Mode Earn App. You’ll architect reliable services, increase speed and resilience, optimize infrastructure, and unlock new features that help users achieve goals and earn points more effectively
- This is a hands-on, high-impact role ideal for someone who loves solving complex systems problems, building scalable APIs, and shipping features that directly impact product performance and user experience
- You will collaborate closely with product, design, data, and frontend engineering to deliver features through rapid development cycles and deployment
- Architect backend systems powering user workflows, notifications, and automation features
- Design APIs and microservices built for performance, efficiency, and scale
- Quickly learn and apply new technologies as needed
- Work with high-volume data systems and event-driven architectures
- Improve observability, monitoring, logging, testing, and alerting
- Identify performance bottlenecks and implement optimization strategies
- Build distributed systems with multiple services, queues, external APIs, and asynchronous data flows
- Ensure uptime, stability, and production resilience
- Build resilient integrations with third-party services
- Work in 2-week sprints with CI/CD and strong code quality practices
- Partner with product, data, and frontend to ship features
- Participate in system design and architecture reviews