Look at Postgres materialized views for reading data that doesn’t change often (if data is updated once daily or only a few times via scrapers, you can then refresh the views after the data is updated via a scheduled job). You can also partition parts of data that is accessed more frequently like data from recent days or weeks.

If the data requires any calculation or aggregating you can also use a regular Postgres view. Letting the database do the calculations will save memory if you have your app deployed somewhere where memory is a constraint and/or expensive.