Middle Backend Engineer

5 days ago

Tallinn, Harjumaa, Estonia 3Commas Full time €40,000 - €80,000 per year


is a leading developer of cryptocurrency trading software, building the leading automation platform for crypto trading
—turning complex markets into simple yet powerful algorithmic strategies.
Our AI-driven bots (DCA, Grid, Signal), deep integrations with TradingView, and a robust API enable traders to automate and optimize across
15+ major exchanges, including Binance, Coinbase, OKX, and Bybit.
We serve a global community of individual and institutional traders and developers who rely on our
security-first, reliable, and battle-tested infrastructure
to run strategies 24/7. Join us to build tools that power real trading volume, tackle hard product and engineering problems at scale, and make pro-level trading accessible to everyone.

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.).

Why Join
Impact at Scale
Drive product innovation for a platform used by millions of traders and developers worldwide.

Strategic Influence
Shape the product roadmap and user experience alongside executive leadership.

Culture of Growth
Join a passionate, talented team where ideas are valued, and careers are accelerated.

Global & Remote
Work flexibly from Barcelona, Tallinn, Cyprus — or remotely, in sync with our distributed product and tech teams.

Equal Opportunity Statement
is proud to be an equal opportunity employer. We believe diversity fuels innovation and welcomes applications from individuals of all backgrounds, identities, and experiences — regardless of race, gender, age, religion, disability, or sexual orientation.

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