Middle Backend Engineer at 3Сommas

3Commas is a leading platform for crypto trading automation. We’re building a modular SaaS product that helps traders worldwide scale their strategies, connect with exchange APIs, and automate routine tasks.

We’re looking for a backend engineer with strong Ruby on Rails experience and a product-oriented mindset. You’ll be responsible for designing secure, scalable features, integrating external APIs, and ensuring performance and quality from day one.

Responsibilities:

• Develop and maintain a modular, scalable SaaS platform using Ruby on Rails.
• Implement new features and improve existing ones in close collaboration with product and design teams.
• Integrate external API services and ensure their secure and stable operation.
• Take ownership of your code in production: monitoring, alerting, and ongoing support.
• Participate in QA processes from the early stages (“shift-left” approach).
• Contribute to code quality through automated tests, code reviews, and refactoring.
• Actively collaborate with cross-functional teams, including DevOps and QA.
• Stay up to date with best practices in backend architecture, security, and performance.

Requirements:

• 4+ years of experience in backend development with Ruby on Rails.
• Strong understanding of PostgreSQL and relational data modeling.
• Familiarity with AWS serverless services (e.g., Lambda, DynamoDB).
• Experience with key-value storage (Redis, Memcached, etc.).
• Solid grasp of software development best practices: TDD, CI, clean code, refactoring.
• Experience integrating external APIs and handling third-party service interactions.
• Understanding of security, scalability, and performance concerns in backend systems.
• Willingness to engage in testing and QA — quality is everyone’s responsibility.
• Comfortable working in Agile teams and participating in code reviews and planning.
• English proficiency at B2 level or higher (written & spoken).

Nice to Have:

• Basic experience with Go and interest in expanding your skills in it.
• Knowledge of Kubernetes and microservice orchestration.
• Familiarity with Kafka, RabbitMQ or other messaging/streaming systems.
• Experience solving high-load challenges and performance bottlenecks.
• Hands-on experience with observability tools (Grafana, CloudWatch, etc.).

What We Offer:

• Product & Architecture Ownership
  Shape a scalable SaaS product — not just write code, but make decisions that impact performance, quality, and business value
  
• Modern Tech Stack
  Work hands-on with AWS Lambda, DynamoDB, Kubernetes, Redis, PostgreSQL, and integrate Go where it fits best.
• Remote-First Culture
  Join a globally distributed team with asynchronous workflows, and optional office access in Barcelona and Tallinn.
• High Engineering Standards
  We care about clean code, test coverage, performance, and the long-term maintainability of our systems.
• Room to Grow
  Learn new technologies like Go, improve your infrastructure skills, or mentor junior developers — we’ll support your evolution.