solid track record, strategies

[user_gary]

RPO is meant to be customized to what an individual company needs
rather than a one-size-fits-all approach to the recruitment function. A good
recruitment partner must be agile and prepared to scale its support as
client needs fluctuate. When done correctly, it is clear that RPO
helps build stronger teams, which positively affects customer satisfaction
and improves business results. The right RPO partner will offer:

• Expertise and a solid track record. Companies are looking to leverage
RPO providers who offer best practices when it comes to volume
recruitment strategies.

Please explain the emboldened parts to me.

[thedeebo]

Not a teacher.

Solid track record=a history of success regarding the area mentioned

Volume recruitment strategies=the ways that someone goes about volume recruiting

The paragraph with the bold words is basically saying that an RPO partner will be an expert at what they do with proven past performance (track record). They will also have effective methods (strategies) for volume recruiting and their methods will be the best.