I am assuming each field and its possible list of value are checkboxes in image. If it is the case, then each search field can become part of where clause with value. For example, WHERE 1=1 AND marital_status = 'Single' AND is_driniking in ('Yes','Occasionally') Please let me know if my understanding is incorrect.

This might be off topic. How will user make sense of data if it is in order of millions?

Assuming you already have a way to send alerts to users and your problem is on server side, did you try any messaging mechanisms like RabbitMQ? Workflow might look like: Product gets updated and that creates and sends a message to message queue Message consumer does the following receives message queries database for all subscribed users send alerts to users

I found elastic search official documentation is best source to understand and learn about it. Start learning with search APIs and you will get used to it soon. You might have got these links already but these are useful ones for me when I was working with Elastic search: https://www.elastic.co/guide/en/elasticsearch/reference/current/search.html https://qbox.io/blog/practical-guide-elasticsearch-scoring-relevancy?utm_source=hashnode.com

Code for humans which can be you going through same code after few months or years. Aim for correctness first before performance

In Mac, I had source code in host and created a share in docker container. And able to run app using that share. But haven't tried gulp + docker.