What you will be doing We are seeking a highly skilled and independent Senior Freelance Web Developer to join us for immediate and high-priority internal development needs. Your work will primarily focus on our proprietary product, such as Kambria Chat Platform, and other critical internal and client development initiatives, contributing to the core infrastructure and functionality that drives our business. This is an initial contract with the strong potential for long-term collaboration, evolving into a consistent partnership if there's a mutual good fit. We value independent problem solvers who can quickly adapt to new challenges and take full ownership of their work. Key Responsibilities Full-Stack Development: Design, develop, and maintain high-performance, accessible web applications and services for our internal products (e.g., Kambria) and operational tools. Architectural Design: Contribute to defining and implementing robust data models, API structures, and scalable architectures. Feature Implementation: Implement complex features, backend functionalities, and intuitive user interfaces from concept to deployment. System Integration: Integrate with various internal and external systems and third-party APIs to enhance product capabilities. Optimization & Quality: Ensure high standards for code quality, testability, performance (e.g., Core Web Vitals), and accessibility (WCAG 2.1 AA). Operational Management: Participate in managing deployment pipelines and ensuring secure hosting environments. Proactive Problem Solving: Take full ownership of tasks, troubleshoot issues independently, and propose effective solutions, working autonomously for periods of 1-2 weeks without constant feedback. Documentation: Create and maintain clear technical documentation. We need you to have 5 years of professional web development experience with a proven track record of successfully delivering production-ready web applications and systems. Expert proficiency in modern JavaScript frameworks. Strong expertise across diverse technical stacks and platforms, demonstrating adaptability and a rapid learning curve for new technologies. Solid understanding and experience with backend development concepts, including API design (REST/GraphQL), database interactions, authentication, and state management. Advanced skills in TypeScript, HTML5, and CSS (experience with Tailwind CSS or CSS Modules highly valued). Proficiency in version control using Git/GitHub, including advanced branching strategies and collaborative workflows. Demonstrated expertise in website optimization for Core Web Vitals, accessibility (WCAG 2.1 AA), and SEO best practices. Experience with deployment processes, CI/CD pipelines, and cloud platforms (e.g., AWS, Azure, GCP). Familiarity and comfort leveraging AI-powered coding tools and agents to enhance productivity and explore solutions. Excellent communication skills in English (written and verbal) for clear collaboration with technical and non-technical team members. Strong sense of ownership and a proactive, results-oriented approach to development. Benefits Employment Details Employment Type: Freelance/contractor. Start Date: asap. Initial Duration: 2–3 months, with a strong view to extend based on mutual fit and project needs. Capacity: We prefer a commitment of 25–35 hours per week (approx. 50-75% capacity) with a potential transition smoothly into a longer-term partnership with the full capacity. Location: Remote, within CET /- 2 hours time zone. Please provide your hourly or daily rate with your application. About us We are Berlin Bytes. As a creative software development and consulting agency, we help businesses navigate the complexities of the digital landscape and unlock lasting value. Together with our clients we design, build, and scale innovative digital solutions & enterprise applications that deliver tangible results.