For the purpose of applying for a lecturer position in Australia in computer science, what is actually a "contribution to technical achievement"? This phrase occurs among the selection criteria but seems to me way too broad from a purely linguistic viewpoint. According to the text describing the selection criteria, a "contribution to technical achievement" is supposed to be separate from research experience, teaching experience, experience outside university, creative achievements, and professional contributions – they are measured separately.
I suspect that "technical achievement", within the context of computer science, is a reference to the production and development of computer software/hardware. Hence, "contributions to technical achievement" is a cue to allow you to give information on any contributions you have made to the development of software/hardware/computing problems (e.g., a program you wrote or helped with). There is probably going to be some overlap with "creative achievements".
The job ad should list a contact. You can ask them.
In my experience the selection criteria are not written very carefully. So I would guess there is no precise answer to your question.