Senior / Principal Backend Engineer (Ruby on Rails)

**Location:** Latin America (Remote) **Experience:** 7\+ years **English:** C1 level **Compensation:** **$8,000 USD / month** **About the Role** We are seeking an exceptional **Senior/Principal Backend Engineer** with deep expertise in **Ruby on Rails** and extensive experience designing and scaling backend systems. This role is ideal for someone who has operated in high\-traffic, data\-intensive environments and can make architectural decisions that impact performance, reliability, and long\-term product scalability. You will work closely with engineering leadership to design backend services, optimize system performance, and ensure high availability. This role requires a strong understanding of concurrency, database engineering, API design, caching strategies, and distributed systems. **Responsibilities** * Design, build, and maintain scalable backend services and APIs using **Ruby on Rails** . * Lead architectural decisions for complex systems, ensuring maintainability and performance. * Implement and optimize **concurrency control techniques** to ensure data consistency at scale. * Plan and execute **database schema migrations** with zero or minimal downtime. * Create high\-quality, secure, and stable **public\-facing APIs** . * Implement effective **caching strategies** and address issues like stale data, cache invalidation, and cache stampedes. * Reduce database load under high traffic through sharding, replication, caching, and messaging queues. * Conduct code reviews and mentor junior and mid\-level engineers. * Collaborate with cross\-functional teams using clear communication in **C1\-level English** . * Work remotely from any country in **Latin America** . **Requirements** * **7\+ years of professional experience** in backend development. * **Expert\-level experience with Ruby on Rails** (performance optimization, ActiveRecord, background jobs, migrations, etc.). * Strong experience with relational databases (PostgreSQL preferred) and distributed systems. * Strong understanding of: * Concurrency control (optimistic/pessimistic locking, idempotency, race condition prevention) * Database migrations with live production data * API design best practices * Caching (Redis, Memcached) * High\-traffic scaling techniques * Solid computer science fundamentals (data structures, algorithms, Big\-O). * Experience with cloud environments (AWS, GCP, or Azure). * **C1 English** (written and spoken). * Located in **Latin America** . **Preferred Qualifications** * Experience with microservices or event\-driven architectures. * Experience with background processing tools (Sidekiq, Resque). * Knowledge of CI/CD pipelines, DevOps practices, and observability tools. * Prior experience in fintech, e\-commerce, or high\-scale SaaS products. **Compensation** * **$8,000 USD per month** * Full\-time, remote position.