Sr. Ruby on Rails Developer

1 tydzień temu

Kraków, Lesser Poland Koinly Pełny etat 80 000 USD - 90 000 USD rocznie

If you'd rather tune queries than sit in meetings, keep reading.

Remote (Europe) | USD $80–90K / year | B2B contractor | 6+ years Ruby/RoR

At Koinly, your Ruby on Rails work will push directly on billions of rows and real performance bottlenecks.


What you'll own

  • Backend services end-to-end: design, build, refactor, optimize
  • Performance: query tuning, caching, background jobs, execution plans
  • Data pipelines: high-volume CSV ingestion, cost-efficient processing
  • Quality: clean, tested Ruby that holds under load
  • Reliability: debug prod issues across code, data, infra
  • Simplicity: champion clarity in system design


Core requirements

  • 6+ years of professional RoR experience.
  • Strong SQL skills, including performance tuning and complex queries.
  • Strong problem-solving and debugging skills in production systems.
  • Experience designing and scaling backend systems (microservices, APIs, background jobs).
  • Eagerness to work with a high-standard engineering team, CI/CD, and testing.
  • Nice:
    high-volume ingestion, perf tools, crypto/fintech exposure, puzzle-worthy side projects.

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Koinly engineering culture

  • Engineering-led:
    Maintainability, test coverage, and reliability come before shipping speed.
  • Craftsmanship mindset:
    We care deeply about clean, readable code that scales gracefully.
  • No heroics:
    Systems are built to be stable, observable, and easy to debug.
  • Autonomy & accountability:
    Small squads, high ownership, minimal bureaucracy.
  • Async-first & remote-first:
    We collaborate primarily through clear writing, not constant meetings.

________________________________________________________________________

Intrigued?

Click "Apply" to read the full job role and see if you'd like to own some of the toughest performance and data problems in crypto tax.

________________________________________________________________________

About Koinly

We're on a mission to simplify crypto taxes and asset tracking.

  • We are one of the fastest-growing crypto tax calculators in the world with solid product–market fit.
  • Trusted and loved: don't take our word for it,
    see what our customers say.
  • Used by hundreds of thousands of investors and accountants, and a partner to major crypto exchanges.

We are building tools to enable further widespread adoption of cryptocurrency by automating the regulatory hurdles of tax compliance and asset tracking.

________________________________________________________________________

Why join Koinly?

Aim High. Work Smart. Scale with Impact.

We build products that people genuinely rely on, turning days of manual work into minutes. Our mission is to reduce compliance friction today while providing insights that help users make smarter financial decisions tomorrow. We tackle hard, complex challenges at global scale with a small, autonomous, and efficient team.

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