How should I handle a reject from a company I'm still interested in?

Don't close the door. A rejection from one role or one hiring manager doesn't mean the company is off-limits. At large companies especially, there are multiple teams, multiple hiring managers, and multiple open roles at any given time. If you had a conversation with a hiring manager, keep that connection warm — reach out when you find a relevant role and ask them to forward your resume to the right person. Frame it as making it easy for them, not asking for a favor: "I came across this role and thought it might be a better fit — here's my resume, I'd really appreciate it if you could pass this along." You're not asking them to advocate for you; you're just asking them to route something. That's a much lower bar and most people are happy to do it.