How could I start doing user research with such a large database?
The techniques that I want to occupy are:
- Focus Group
- Contextual Immersion
My doubt is how to start working with a large volume of users.
You already seem to have the methods in mind and ordered too. But to start with may be do a Cohort Analysis and create sensible groups based on probably job-title, country or another factor considering what is available in the data (assuming you already have some data on the users). From thereon, you may create a focus group with people representing different cohorts and proceed as planned towards Contextual Immersion. There may be multiple focus groups based on location may be (just an example) - two focus groups in two different countries.