Deliverability Engineer (Instantly / Smartlead / Maildoso / Infra Experience)

I’m looking for an engineer with hands-on experience maintaining deliverability at scale for platforms such as Instantly, Smartlead, Maildoso, Mailreef, Infraforge, or similar cold email infrastructure providers. This is not a request for a generic email consultant. If your work consists primarily of checking SPF, DKIM, DMARC, MX records, or running basic deliverability audits, please do not apply. My infrastructure is already configured correctly. What I’m looking for is someone who understands how to maintain a high inboxing rate over time across a large sending infrastructure. Specifically, I’m looking for someone who can provide a clear, practical strategy covering topics such as: * Extending inbox and domain lifetime * Maintaining high inbox placement over months, not days * Sender rotation strategies * Content and signature rotation * Warm-up strategy (when to use it and when not to) * Volume management * Domain and mailbox reputation management * Detecting reputation degradation before it impacts performance * Operational processes used by large cold email platforms I’m not looking for theory. I’m looking for someone who has worked on these problems in production and can explain what actually works. If you’ve helped build or maintain deliverability systems for a large cold email platform, I’d love to speak with you.