JavaScript Software Engineer(M/F/X)

We are currently seeking a JavaScript Software Engineer to join one of our clients, a leading international player in cybersecurity and open-source software, responsible for a credential management platform used by over 40,000 organizations worldwide.Your Mission:Reporting to the Client team, you will go beyond the role of a traditional developer to become a guardian of security, data integrity (zero-trust), and a seamless user experience. You will work across all client applications (browser extensions, desktop applications, CLI, and SDKs) used daily by over half a million users.Key Responsibilities:JavaScript Software Engineering: You design and implement new features for browser extensions (Chrome, Firefox, Safari, Edge), the desktop application, and various SDKs. You transform UI/UX designs (Figma) into reusable, animated components (Storybook).Security & Cryptography (Zero-Trust): You integrate client-side business logic (end-to-end encryption, local data persistence, strict data validation) while adhering to the highest security standards. Every change requires a rigorous risk analysis.Quality & Rigor: You strive for technical excellence through systematic code reviews and ambitious test coverage (Unit & E2E), aiming for a minimum of 80% coverage.Deployment & Reliability: In collaboration with Senior Engineers, you participate in release planning to minimize service downtime and contribute to the optimization of CI/CD pipelines.Candidate Profile:Experience: Minimum of 3 years of software development experience in a professional company setting (excluding internships, which remain valued for more junior positioning). A background in a startup, scale-up, or a flat, agile environment is essential.Technical Stack: Mandatory mastery of JavaScript (familiarity with a React-dominant environment is a major plus). A strong awareness or prior experience in cybersecurity, cryptography, or open-source software is highly appreciated.Languages: Fluent English is mandatory (all documentation, meetings, and internal communications are conducted exclusively in English).Mindset: A strong startup mindset (flexibility, constructive feedback culture, autonomy). You are passionate about web ethics, data privacy, and enjoy finding simple solutions to complex technical problems.Package & Benefits:Contract: Full-time permanent contract only (CDI via Remote.com).Salary: Based on profile and country of residence.Remote Work: 100% Full Remote from Europe.