This post emphasizes the importance of working on legacy projects for engineers, arguing that such experiences are crucial for career growth. Comments from users highlight how engaging with outdated systems helps engineers understand corporate project management and the underlying challenges faced by their predecessors. These projects not only teach engineers valuable lessons about coding and problem-solving but also contribute to career advancement by building niche expertise. Furthermore, there's a contrast drawn between legacy and greenfield projects, where the author suggests that valuable learning occurs in both scenarios, but legacy work can be more difficult and rewarding.