To sustain motivation and enthusiasm as a web developer in your late career, focus on staying updated with the latest technologies and trends in the industry. Set personal and professional goals to keep challenging yourself and stay engaged. Collaborate with colleagues and participate in the developer community to stay inspired and share knowledge. Consider mentoring younger developers to pass on your expertise and stay connected with the evolving landscape of web development. Additionally, prioritize work-life balance and take time for self-care to prevent burnout and maintain a positive outlook on your career.