Fullstack Software Engineer - React, Kotlin & Ruby on Rails (x/f/m)

Join ACAI (Advanced Calendar Improvement) , a team dedicated to making day-to-day practice operations more efficient and less mentally exhausting for healthcare professionals and their teams. Practice operations are often fragmented across post-its, emails, SMS, phone calls, oral instructions, and individual memory. This makes it difficult for teams to know what needs to be done, who owns it, how urgent it is, and what has already happened. As a Software Engineer, you will help build products that centralise work, improve coordination, and automate administrative tasks across the practice; directly contributing to a smoother experience for healthcare professionals, staff, and patients. Your responsibilities Develop reliable, intuitive features for Task Manager, Patient Flow Management, patient intake, appointment proposals, and telesecretaryship workflows Help practices coordinate the patient journey from arrival to completion of a visit, including waiting-room status, care steps, walk-ins, delays, patient movement, and check-out Design solutions that reduce the time healthcare professionals and staff spend manually creating, sorting, remembering, relaunching, and completing tasks Work across backend and frontend technologies to deliver high-quality, user-facing experiences Build performant, reliable, and observable services that can support Doctolib's growing user base and complex healthcare workflows Apply strong privacy, data protection, and security practices when working with personal and health-related information Partner closely with Product, Design, Data Protection, and other engineering teams to understand problems and deliver valuable solutions About our tech environment Our solutions run on a single, fully cloud-native platform serving web and mobile applications across multiple languages and countries, each with its own regulatory and specialty-specific requirements. To address these challenges, we are modularising our platform through reusable components and a distributed architecture. On ACAI, you'll primarily work with Ruby and Kotlin on the backend and React with TypeScript and Rails on the frontend. Doctolib's broader technology environment also includes Java, Python and Swift. We leverage AI in an ethical manner across our products to empower patients and healthcare professionals. Discover our AI vision . Who you are Before you read on, if you do not have the exact profile described below but feel this role matches your skills, we still encourage you to apply. You have 3+ years of experience as a full-stack Software Engineer, ideally working on user-facing products You have experience building scalable, robust, and reliable systems You are comfortable working with sensitive personal or health-related data, such as PHI and PII, and apply a strong privacy, data protection and security best practices by default You have experience collaborating closely with Product, Design, Security, and other engineering teams You have a user-first mindset and care about solving real problems for customers You use AI tooling thoughtfully as part of your engineering workflow You enjoy sharing knowledge, contributing to team discussions, and helping others grow You demonstrate a growth mindset and a strong learning agility You are fluent in English and comfortable working in a collaborative, discussion-oriented environment Experience in healthcare, medical software, fintech, or another highly regulated domain would be a plus. What we offer A Deutschlandticket (Germany-wide public transport pass) fully paid for by Doctolib 28 vacation days + 1 additional day for each full calendar year of employment (up to a maximum of 30 days) Work from abroad for up to 10 days per year thanks to our flexibility days policy Company health insurance with great supplementary benefits through our partner Allianz Company pension scheme (bAV) through Allianz with an employer subsidy of 40% (15% within the probationary period) The Doctolib Parent Care…