The knowledge of the following skills is required for software developer:
1. Data Structures and Algorithms
2. Programming Languages
3. Source Control
4. Text Editors
5. IDEs (Integrated Development Environment
6. Databases
7. Operating System
8. Networking Basics
9. Basics of Testing
10. Cross-Platform Software
11. Encryption and Cryptography
12. SDLC (Software development life cycle)
13. Microsoft Excel
Also, watch this video on Software Developer for more information: