The actual work being proposed must meet the relevant requirements. Future duties cannot substitute for the current role.
Assess each stage honestly
Identify the work that will actually begin and the conditions for later changes. Do not merge incompatible duties into a fictional single assignment.
Proof of Canadian citizenship, the credential the listing names, the regulator’s confirmation where a licence is relied on, and an employer letter that identifies the listed profession and the professional duties. For TN purposes the question is whether the whole of the work is professional geological practice, described clearly enough that an officer reading the letter sees one qualifying assignment rather than a mix of professional and technician tasks. The Scientific Technician/Technologist entry can work, but it carries its own conditions: theoretical knowledge of the discipline, the ability to solve practical problems, and a role that supports a professional such as an engineer. Ask the employer to title the position Computer Systems Analyst and to describe the requirements-gathering, design and specification duties in the support letter, with coding mentioned as a component. Canadian or Mexican citizenship, temporary entry and permitted prearranged professional work remain necessary; neither a customer’s urgency nor technical equipment replaces those conditions.