core skills needed by all software developers are:

The core skills needed by all software developers are:

Core Skill	Description
Read Code	The ability to understand an existing code base in order to analyze its behavior and make fixes or enhancements to it.
Write Code	This does not include any significant amount of design – just the basics of coding. An example is being able to write a method given the desired behavior (inputs, outputs, pre-conditions and post-conditions).
Design Software	The ability to determine what code is necessary to achieve some specified functionality, particularly the higher-level structure or organization of the code.
Awareness of the Software Development Life Cycle	This is an awareness of the 'big picture' of software development beyond just writing code - how the other life cycle stages (requirements, design, testing, and maintenance) impact coding and vice-versa. This includes an understanding of the types of methodologies (e.g. Agile or Waterfall) that can be used to progress through this cycle.
Use of Libraries and Frameworks	This skill could also be called "Reuse Existing Code". This skill includes the ability to search for and evaluate libraries and frameworks based on how effectively they meet your needs and the ability to integrate the chosen package into the software you are writing.
Debugging	The ability to analyze the behavior of code to diagnose a problem and find the underlying cause. This includes but is not limited to using a debugger.
Use of Integrated Development Environments	The ability to effectively use modern IDEs and an understanding of their strengths and weaknesses.
Use of Version Control	This skill includes basic use of a version control tool as well as a general understanding of software configuration management.
Automated Unit Testing	This is the ability to unit test code by writing automated tests.
Refactoring	The ability to revise existing code without impacting its functional behavior.
Use of Build Automation	This goes beyond simply writing a build script to include other related automation like continuous integration, automated deployments, and static code analysis tools.