How to enrich data for 1.5M companies cost effectively?

I’m working on a recruiting platform where we maintain a database of ~1.5M distinct companies tied to candidate work history.

Right now, we mostly have:

Company names (often messy / non-normalized) Employment time ranges

But to unlock a bunch of product use cases (search, filtering, prioritization), we need to enrich these companies with things like funding history & funding stage, type of company and growth signals.

I’m thinking of how we can get all this data in a cost effective way.

Some of the tradeoffs we’re actively thinking through:

Batch enrichment vs on-demand enrichment Pre-enrich everything vs lazy enrichment on first use Refresh cadence (on demand vs fixed cadence)

Would love to get some tips from folks who’ve been done this before. Thanks!