Google won't tell anyone the exact formula, and no one legitimately knows all of it. But the pieces that matter are well understood, and none of them are secret. They're just easy to skip.
Relevance
Does your website clearly match what the person searched? If someone searches "emergency plumber Tacoma" and your site talks generally about "quality plumbing services" with no mention of emergency calls or Tacoma, that's a weak match, no matter how good your work actually is.
Location
Does Google understand where you work? This comes from your address, your service area pages, and consistent location information across your website and your Google Business Profile. Vague or missing location signals make it hard for Google to show you to the right nearby customers.
Google Business
Is the profile complete and consistent? Business name, category, hours, service area, and photos all matter, and they need to match what's on your website. A profile that's half-filled out, or contradicts your site, works against you.
Reviews
Do customers trust the company? Review count and rating are one of the clearest trust signals Google has, and they're one of the clearest signals a customer looks at too. Ask happy customers for reviews. It matters more than almost anything else on this list.
Website
Does the website support the same information? Services, service area, and business details should be consistent and clearly written, with a page dedicated to each real service. This is the part a website you actually control has the most influence over.
Authority
Does Google have enough evidence that the company is legitimate and useful? This builds over time from consistent information, real reviews, a working website, and, where relevant, mentions or links from other credible local sources.
None of this guarantees a specific ranking, and no one who tells you otherwise is being straight with you. What it does is give you a real foundation to compete on, instead of hoping.