Build and scale Ruby systems that power billions of crypto tax transactions. Join Koinly to tackle deep technical challenges, refactor complex code, and shape high-performance financial architecture. Architect the systems that make crypto tax simple and performance effortless. Simplifies crypto taxes for millions of users. Our cryptocurrency tax platform transforms billions of blockchain transactions into accurate financial records through reliable, high-performance engineering. We're hiring a Staff Software Engineer to join our Engineering team. The mission of this role is to strengthen our Ruby systems by simplifying complexity, improving performance, and shaping the architecture that keeps financial data precise and fast. Koinly is a remote-first and async by design, with strong product-market fit in a niche (and booming) domain: crypto taxes. If you thrive on deep technical work and value autonomy, clarity, and craft, you’ll fit right in. Apply below to help build the backbone of large-scale financial systems.

Responsibilities

Design and develop scalable backend systems that process billions of financial transactions.
Provide technical direction across projects and collaborate with product and engineering leads to define priorities and architecture.
Own project delivery: from design and implementation to performance and reliability in production.
Refactor and modernize core Ruby systems to improve maintainability, readability, and speed.
Mentor other engineers through technical reviews, design discussions, and clear documentation.

What you bring

7+ years of backend experience with Ruby on Rails at scale, with at least 2 years as a senior engineer, influencing cross-team initiatives.
Proven record improving system performance and code quality.
Strong understanding of data flows and software design principles.
Experience working cross-functionally in async, remote environments.
Clear communication and ownership mindset.

Bonus