Senior Typescript Engineer (Device / SDK) - FinTech / Crypto

Hey! Nice to see you! At Incubly , we believe that great people want to work with great people, so we started to build a company that will attract great minds and that we can achieve everything not by feeling that we work, but just having fun. Our mission is to mainly support tech companies and startups (scaleups) in fast and high-quality scale-up of their teams and boost their product development, testing, and deployment; so, we can succeed together. We are currently working with a French company which is a leader in security and infrastructure solutions for cryptocurrencies and blockchain applications. It has a team of more than 400 professionals developing a variety of products and services to safeguard cryptocurrency assets, including worldwide leading hardware wallets. Join the Device Experience team at Ledger as a Senior TypeScript Engineer and help shape how users interact with hardware wallets. You’ll work within a team of 6 engineers and a team lead, contributing to both Ledger Live (mobile and desktop) and the Device SDK, a strategic project enabling seamless Web3 integrations. Your daily responsibilities Contribute within a modern AI-enabled engineering workflow utilizing tools such as Claude Code, Cursor, and Gemini Develop and maintain the Ledger Live stack across mobile and desktop applications, as well as its broader ecosystem at Ledger Contribute 100% to open-source projects within our monorepo: ledger-live Support modularization efforts by contributing to the Device Management Kit for internal and external usage Maintain and enhance the @ledgerhq/hw-transport-* libraries, enabling secure communication with hardware wallets across multiple channels (U2F, HID, WebUSB, Bluetooth) and platforms (Web, Node, Electron, React Native) Contribute to strategic initiatives such as Clear Sign Develop and improve the My Ledger section, enabling firmware updates and app installation on devices Collaborate closely with Firmware, Product, and other engineering teams Partner with QA to further automate and strengthen testing processes Investigate and resolve complex blockchain-related edge cases and bugs We need you to have At least 5 years of experience in software development, including experience in a Tech Lead role A curious mindset and positive attitude, with the ability to thrive in a highly collaborative environment Strong proficiency in JavaScript and TypeScript Professional fluency in English Would be great if you have Experience with Functional Reactive Programming (e.g. RxJS) Experience working with devices using APDU commands, messaging protocols, and blockchain technologies Experience with Bluetooth or HID communication Previous experience working with embedded systems Open-source contribution experience Strong understanding of SOLID principles Experience with Clean Architecture Experience with GitHub Actions or similar CI/CD tools Our offer In addition to great company and challenging projects, we can offer much much more, i.e. Agile and friendly atmosphere, non-violent communication, and full respect for diversity Possibility to choose from onsite (in Lodz, Poland) or hybrid work (2-3 days a week in our office in Łódź city centre). Business trips to Paris as needed, typically once every three months Remuneration on B2B: 1300- 1500 zł net/ MD