Ruby Labs is looking for a Senior Backend Engineer to help design, build, and scale the core backend systems that power our AI product, Use.ai. This is a high-ownership role for an engineer who loves solving distributed systems challenges and driving both feature delivery and infrastructure excellence.

What You'll Do

Deliver new backend features with a focus on scalability, performance, and reliability.
Maintain, optimize, and improve existing services and infrastructure.
Design, deploy, and operate backend services across AWS, Cloudflare, and other environments.
Implement and evolve monitoring and observability using tools such as Sentry, OpenTelemetry (OTel), logging, alerting, and related platforms.
Investigate and resolve production issues across distributed systems.
Write clean, maintainable code aligned with SOLID principles, system design, and backend best practices.
Lead incident investigations, root cause analysis, and system reliability improvements.
Contribute to architectural decisions, documentation, and infrastructure planning.
Collaborate with high standards for communication, ownership, and delivery.

What We're Looking For

8+ years of overall professional experience.
Deep expertise in distributed systems, system design, and backend architecture.
Strong understanding of database fundamentals, indexing, consistency, replication, transactions, and storage trade-offs.
Proven ability to design scalable and resilient systems.
Fluency in Node.js backend development.
Strong grasp of software engineering principles, including SOLID.
Experience debugging complex issues in production environments.
Experience with cloud infrastructure (AWS) and backend service deployment.
Experience implementing monitoring and observability using tools such as Sentry and OpenTelemetry (OTel), including tracing, logging, and alerting.
High standards for code quality, reliability, and communication.
Deep knowledge of Redis, including caching, pub/sub, queues, replication, persistence, and performance tuning.
Strong experience with AWS services, including compute, serverless, networking, storage, security, and infrastructure-as-code.
Experience with Cloudflare Workers, edge routing, caching, and security primitives.
Familiarity with Sentry performance monitoring and OpenTelemetry instrumentation at scale.
Comfortable working in timezone ±2 hours from UK time.

Nice to Have

Experience working in startup environments or small, high-autonomy engineering teams.
Passion for building and improving infrastructure, developer experience, and observability.

Technical Stack

Node.js
AWS
Cloudflare Workers
Redis
Sentry
OpenTelemetry

Benefits & Compensation

Remote Work Environment.
Unlimited PTO.
Paid National Holidays.
Company-provided MacBook.
Flexible Independent Contractor Agreement with tax advantages, networking opportunities, reduced employment obligations, and freedom to work from anywhere.