Set a custom LinkedIn URL first (Settings, Public profile, Edit URL) so the code points at linkedin.com/in/yourname rather than a string of digits: shorter link, smaller code. Company pages use linkedin.com/company/name.
Keep the design restrained. A single colour, soft eyes and a short frame line read as professional on a card and on the last slide of a deck. If the card is dark, use the transparent background and light dots, and read the scan check warning about inverted codes on Android.
Questions
LinkedIn has its own QR code. Why make one here?
LinkedIn’s in-app code only works inside LinkedIn’s scanner. A standard code opens your profile from any camera, exports as SVG for print, and can carry your branding.
Profile or vCard code for a business card?
A vCard code saves your details offline in one tap. A LinkedIn code starts a connection. Many cards carry one of each.