Senior Software Engineer - Full Stack

About CoinList CoinList is a leading crypto financial platform supporting the full lifecycle of crypto investment. We offer a comprehensive suite of services, including token sales, trading, lending, staking, and access to DeFi opportunities. CoinList has helped raise over $1.1 billion for groundbreaking projects, establishing itself as the go-to platform for innovative blockchain companies. Our platform is trusted by validators, miners, founders, crypto funds, and a broad array of crypto enthusiasts globally. The Opportunity We’re looking for a Senior Software Engineer (Full Stack, Backend-leaning) to join our Core Team. You’ll play a key role in building and scaling the core financial infrastructure that powers CoinList’s money movement, wallet, and custody solutions, while also owning and improving our web application experience. This is a high-impact role where you’ll ship production systems, shape product direction, and help set technical standards for the team. This role is ideal for a full stack engineer (backend-leaning) who thrives in product-focused environments, cares deeply about UX and frontend polish, and is excited to own both backend infrastructure and web product experiences in a fast-paced fintech startup. What You’ll Do: Design, build, and scale robust financial software systems and backend services that power money movement, custody, and payment flows. Develop and maintain web frontends (React, LiveView) with a focus on UX, collaborating closely with designers to deliver polished, user-friendly products. Architect and optimize wallet and custody solutions for a variety of cryptocurrencies, ensuring security, reliability, and scalability. Own projects end-to-end: From concept and design through implementation, testing, deployment, and monitoring. Collaborate cross-functionally with product, compliance, and other engineering teams to deliver secure and delightful financial products. Participate in code reviews, share knowledge, and help upskill junior engineers. Identify and address performance bottlenecks, reliability gaps, and opportunities for automation. Influence product and technical direction, working closely with leadership and crypto founders. Requirements 5+ years of professional engineering experience shipping high-quality code in production environments Strong coding fundamentals Proven experience scaling financial systems (fintech, payments, trading, or crypto/DeFi platforms). Security-first mindset and deep understanding of best practices in financial software development. Experience with, or open to learning and working with, Elixir and LiveView (backend and frontend). Demonstrated experience building and maintaining production web frontends (React, LiveView, or similar). Track record of product ownership, attention to detail, and working collaboratively with designers. Bonus Skills: Experience with distributed systems or microservices architecture. Prior Elixir experience is a plus but not required-willingness and ability to learn is key. Familiarity with blockchain protocols, crypto custody, or staking systems. Experience integrating with payment rails, ledgers, or compliance systems. Contributions to open-source projects or crypto communities. Backend engineering fundamentals with experience in modern languages (Elixir, Ruby, Go, TypeScript, Python, etc.). Tech stack:  Elixir (primary), LiveView (frontend), Ruby. Most new development is in Elixir and LiveView. Legacy systems in Ruby on Rails and React. Benefits $128,000 – $179,000 USD base + significant equity (depending on experience/location)