Sign the contract and pay the contractor 30%. Once the product is in place and deployment begins, pay another 30%. After successful debugging and acceptance, pay another 30%. If it runs smoothly for several years, then release the final 10%. That's the theory.
If you're curious about what it feels like to have a vaginal birth, this article is worth reading. It shares a useful tip:
To reduce the risk of tearing or needing an episiotomy, apply moisturizing body lotion or elasticity cream during pregnancy to improve skin suppleness.
To make someone respect and fear you is the way to make use of them.
You have to care about their interests and hold their secrets. Let them both respect and fear you. If you care about their interests, they will respect you. If you hold their secrets, they will fear you.
When they both respect and fear you, they will be loyal to their duties and honestly provide you with the best service for your money.