Job descriptionAt Koinly , we’re looking for a Tech Lead (Ruby on Rails) to push our financial data platform to the next level. This role is roughly 80% coding, 20% technical leadership and is ideal for a senior engineer who thrives on solving performance bottlenecks, guiding peers, and shaping architecture without the management overload. More about us is included at the end of this page. 🔑 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. 🚀 The challenge ahead Koinly’s backend reconciles billions of crypto transactions across 900+ integrations . Every millisecond and data point must be accurate. As usage surges, the challenge is keeping our systems fast, reliable, and easy to evolve . You’ll lead the effort to: Keep performance high as scale increases. Refactor and simplify complex Ruby systems. Mentor senior peers and shape the next generation of our backend architecture. Clean code and clarity at massive scale, that’s the mission. 🛠️ What you’ll do Performance and reliability Profile, tune, and reduce latency across high-volume ingestion and reconciliation systems. Optimize Postgres queries, caching, and background processing. Architecture and refactoring Own and evolve our Ruby + Postgres backend. Lead major refactors to improve maintainability and scalability. Design data flows and pipelines that reconcile billions of records accurately. Technical leadership Set coding standards, review designs and pull requests, and coach senior engineers through code review. Leadership through mentoring, reviews, and technical decision-making (without management overhead). Collaboration Collaborate asynchronously with product, design, and leadership. We're light on meetings, heavy on ownership. Collaborate through lightweight RFCs and clear written communication What success looks like? You’ll make our systems faster, our codebase simpler, and our engineering culture stronger. 🧠 What you bring 7+ years’ experience and deep proficiency in Ruby on Rails. Proven results improving performance and reliability in production databases (Postgres preferred) . Strong async communication and mentoring skills. Track record of solving performance issues through thoughtful design and clean code. Ability to analyze and simplify complex systems. Experience with data pipelines, ETL, or reconciliation systems. Bonus points: You have experience working in an async-first, distributed team. You've tuned Postgres in production. Debugged concurrency issues (deadlocks, race conditions). Worked in fintech, taxtech, open banking, or other regulated data domains. Familiarity with blockchain or DeFi data structures. Understanding of observability practices (metrics, tracing, SLOs). ❎ Don’t meet every checkbox? That’s fine. We care about skill, drive, and how you think. ⚙️ K oinly engineering culture Engineering-led values: 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 🤝 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.