Essential skills for backend development include proficiency in programming languages such as Python, JavaScript (Node.js), Java, or PHP, depending on the technology stack used. Additionally, knowledge of databases like MySQL, MongoDB, or PostgreSQL is essential for storing and managing data. Understanding of server-side frameworks, such as Express.js, Django, Spring Boot, or Laravel, is also important. Backend developers should be familiar with RESTful API design, authentication methods, and security best practices. Strong problem-solving skills, attention to detail, and the ability to work with third-party APIs are also valuable traits for backend developers.