The main tasks and job responsibilities of software engineers are...

To make programs, fix existing software to correct errors and improve performance.
Design and create software systems, using scientific analysis and models using math.
Develop specifications and performance requirements and resolve customer problems.
Analyze information to determine, recommend and plan installation of a new system or modification of an existing system.
Develop and direct software system testing.
Talk with customers and/or other departments on project status, and technical issues such as software system design and maintenance.
Advice customer about, or perform, maintenance of software system.
Coordinate installation of software system.
Monitor functioning of equipment to ensure system operates correctly.
Prepare reports and correspondence concerning project specifications, activities and status.
Evaluate factors such as reporting formats required, cost constraints, and need for security restrictions to determine hardware configuration.
Supervise and assign work to programmers, designers, technologists and technicians and other engineering and scientific personnel.
Train users to use new or modified equipment.
Specify power supply requirements and configuration.

Sources: google images and bing images