"Koinly is a successful product used by crypto investors around the world helping them make sense of complex portfolios and tax obligations across chains wallets exchanges and Defi protocols. The bar is simple to describe and hard to deliver a user should be able to reconcile thousands of transactions and file their taxes in under 20 minutes. We're looking for a Backend Staff Engineer to take deep ownership of our data platform - the engine behind products at the intersection of crypto finance and tax. You'll own a high-performance distributed data-processing backend written in modern TypeScript - the system that ingests normalizes and reconciles on-chain and exchange data at scale and turns it into numbers people file taxes with. Correctness is not negotiable here a wrong balance is a wrong tax return. This is a senior hands-on role for someone who combines exceptional engineering craft with genuine product ownership. We expect you to lead by example writing high-quality code making sound architectural decisions and raising the bar for the entire backend team. We’re a remote-first async-first startup with deep product-market fit. If you value autonomy technical excellence and clear communication over meetings and process complexity Koinly is the place for you. Read On For Responsibilities Requirements And Who We Are. 👇 Role at a glance Mission Own the distributed backend data engine end-to-end guaranteeing precision performance and scale for complex crypto tax data. Location Remote - Strictly Europe (EU / UK timezones) + Note we won’t review job applications from outside Europe. Employment B2B Contract. Compensation USD $80k – $100k/y. Perks 32 days PTO (incl. public holidays). Experience 8+ years with a focus on complex data-heavy distributed systems. 🚀 Work within one of the most rapidly growing industries in the world What we're looking for We're looking for someone who thrives on complex business-critical financial systems - architectural depth high throughput high-volume ETL and high stakes. You’ll focus on optimising refactoring and elevating our backend architecture while ensuring deterministic execution high availability and financial-grade correctness. Above all we value a high sense of product ownership exceptional code quality autonomy and openness you take responsibility for outcomes not just tasks and you work independently while staying transparent and collaborative. We also expect Deep understanding of distributed system architecture and the design patterns that support it at scale - queues workers idempotency backpressure rate-limiting and retries. Work closely with product and engineering leads serving as a key technical partner to evaluate ideas propose architectural solutions and take real ownership of our backend data pipeline. Real production-level DeFi experience - AMMs lending staking LP positions and bridges. You understand what on-chain activity actually means and you can spot data anomalies instantly. Advanced data modeling and SQL skills with a track record of tuning performance on massive PostgreSQL datasets. Proven professional experience with Rust - you’ve used it in production or professional settings can read and write it confidently and are ready to work in it where extreme performance demands it. Fluency with the latest AI development tools such as Claude/Codex/Cursor and the judgment to put new tools to work effectively in a professional workflow. Tech stack You should have deep production-level experience across our core stack Core TypeScript (strict modern) on the Bun runtime with modern TS tooling (oxlint Biome) Distributed processing with RabbitMQ and Redis (ioredis) PostgreSQL - schema design query optimization and migrations at scale Vitest for unit and integration testing Sentry for error monitoring Data & Blockchain Blockchain libraries and node/indexer APIs RPC and provider reliability patterns On-chain data decoding ABIs event logs traces token standards transaction semantics Data parsing and wrangling csv-parse xlsx (SheetJS) node-html-parser Integrations against messy inconsistent third-party APIs and file formats Infrastructure & Tooling PostgreSQL Heroku GitHub JIRA Nice to have Public portfolio of projects available on GitHub or similar platforms. Deeper Rust experience especially in performance-critical data processing. Background in financial products double-entry accounting or tax domains. Familiarity with Ruby (our services interoperate with a Ruby codebase). Knows and understands our product. ✔️ Don’t tick all of the boxes? Neither do we 🤷 We're driven by hiring not only by experience and relevance but also by ambition. We celebrate anything ‘outside of the box’ so if you don’t meet every single listed criterion please do still apply - we’d love to hear from you. That said there are two hard gates for this role Expert-level TypeScript. You should reach for strong typing instinctively not as an afterthought. We deal with complex financial data where ""mostly correct"" isn't good enough your TS skills should reflect that. Deep Distributed Systems & DeFi context. This is a Staff-level role. You need a deep understanding of async queue architectures idempotency and how smart contracts execute on-chain. We need someone who can hit the ground running with a complex high-throughput pipeline. Why join Koinly as a backend engineer? One of the fastest-growing Crypto Tax Calculators in the world with solid product-market fit. Trusted and loved See what our customers say on Trustpilot. Direct impact Our users rely on Koinly for their financial compliance. Every performance optimization and reconciliation engine improvement you ship directly reduces the stress of hundreds of thousands of investors. True ownership We don't believe in ""ticket-flipping."" You'll own core data services from architecture through deployment and scaling. You have the autonomy to make system decisions that stick. High-signal low-noise We're remote-first and async-first. We don't do unnecessary meetings or processes for the sake of process. You’ll have long blocks of deep work time to actually build. 🚀 Come and shape the future of crypto tax with us We aren't just building a calculator we're building a platform that empowers crypto investors to make the best decisions for their financial future. If you’re ready to own a piece of that journey and build a product people actually need we want to hear from you. Our take on Diversity Inclusion and Belonging The diversity of our team reflects the diversity of our community and customers. We not only welcome but celebrate diverse communities. We feel we have an empowering environment where everyone is supported and respected and we want you to feel this too. We welcome new ideas thinking and approaches and listen intently and we are strongly committed to learning and improving on this as we grow. Compliance and privacy Due to our domain background checks are required before joining. By applying you consent to processing your data for recruitment purposes per our privacy policy."