Tech Lead | Ruby + Rails | Scale Systems Handling Billions
Own and optimize a Ruby + Postgres backend processing billions of crypto records. 80% hands-on, lean team, high autonomy, zero bloat. Pure scale and performance work.
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Scale financial data systems that handle billions of transactions.
At Koinly, we’re looking for a Tech Lead who thrives on scaling high-volume systems, raising code quality, and guiding senior engineers while staying deeply hands-on.
This role is ~80% coding, ~20% technical leadership. You’ll work directly on our Ruby on Rails backend, built by engineers who care about craft, speed, and impact. The focus is not only on performance but also on refactoring complex code, making systems more maintainable, and improving how we think and organize at scale.
Key details
- Report to: Engineering Manager
- Squad: Core
- Team size: 5 senior engineers (within a 10-person backend group)
- Location: Remote, preference for Europe-based candidates
- Salary: USD $100k–120k / year
- Type: Full-time (B2B contractor)
- Experience: 7+ years, prior leadership of senior peers
- Start date: ASAP
- Mission: Lead a small senior team while staying hands-on to solve performance bottlenecks and push technical excellence.
Why this role exists
Our platform ingests and reconciles billions of financial transactions from 900+ integrations. Tax and compliance for crypto investors depend on absolute data quality.
The challenge isn’t just speed, it’s clarity and maintainability at scale. We need a Tech Lead to:
- Keep performance high as data volumes grow.
- Raise the bar on code quality and refactoring.
- Guide a senior team in making thoughtful architectural decisions.
What you’ll do
- Stay hands-on (~80% of your time) while leading by example.
- Refactor and improve complex Ruby code to make it cleaner, more maintainable, and performant.
- Set coding standards, review designs and pull requests, and coach senior engineers through code review.
- Own and evolve the Ruby + Postgres backend that powers global crypto tax reporting.
- Profile, tune, and reduce latency across high-volume systems.
- Contribute to architectural decisions and roadmap planning.
- Collaborate asynchronously with product, design, and leadership without unnecessary meetings.
- Leadership through mentoring, reviews, and technical decision-making (without management overhead).
What you bring
- Proven experience scaling large, data-intensive systems.
- Strong expertise in Ruby/Rails and codebase refactoring.
- Track record of solving performance issues through thoughtful design and clean code.
- Ability to analyze complex systems and simplify them without regressions.
- Experience with data pipelines, ETL, or reconciliation systems.
- Comfortable in an async-first, distributed team.
Bonus points if you’ve:
- Tuned Postgres in production.
- Debugged concurrency issues (deadlocks, race conditions).
- Designed ingestion pipelines for messy external data.
- Worked in fintech, taxtech, open banking, or other regulated data domains.
- Dabbled in blockchain protocols or DeFi.
❎ Don’t meet every checkbox? That’s fine. We care about skill, drive, and how you think.
Ready to take on the challenge?
If scaling complex systems, raising code quality, and leading a senior team while staying hands-on excites you, we’d love to hear from you.
👉 Apply now via the “Apply” button and let’s start the conversation.
Due to regulatory requirements, background checks are part of our process.
- Department
- Tech
- Role
- Tech Lead
- Remote status
- Fully Remote
Workplace & culture
All of our team members work remotely and we all collaborate effectively to embrace the challenges of calculating cryptocurrency taxes and making our customers’ lives easier.
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.
Our users get through their crypto taxes in 20 minutes; many will save days or weeks, filing their crypto taxes for the first time, giving them the confidence to build a portfolio for the long term.
We are building tools to enable further widespread adoption of cryptocurrency by automating the regulatory hurdles of tax compliance and asset tracking.
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