Migration of two existing custom Shopify POSUI apps to new server

SHOPIFY CUSTOM APP MIGRATION — LIFT-AND-SHIFT, NO DEVELOPMENT I'm looking for an experienced developer to perform a clean lift-and-shift migration of two existing custom Shopify apps from my current development agency's hosting infrastructure onto hosting that I own and control. This is purely a migration job. No new features, no code changes, no enhancements. The apps work as intended in their current state — I simply need them moved. THE TWO APPS BEING MIGRATED 1. A custom currency recorder app used for dual-currency (KYD / USD) transaction reconciliation in our Shopify store. 2. A custom Shopify POS UI extension that integrates with our in-store loyalty program (Jericommerce). Both apps are currently live and in operational use. They cannot go dark, even briefly, during the migration. WHAT I NEED FROM YOU - Coordinate with my current developers to obtain the source code, environment variables, deployment configurations, and any other materials needed to redeploy the apps on new infrastructure. - Recommend a target hosting environment that makes the most sense long-term for this kind of workload (e.g. Render, Heroku, AWS, DigitalOcean) and explain why. - Stand up the new hosting environment under accounts that I own. - Deploy the apps onto the new hosting in a staging state, run them in parallel with the existing deployment, and confirm they are functioning identically to the current production version. - Confirm with me, in writing, that the migrated apps are fully functional before any cutover takes place. I will not authorize the cutover until you have demonstrated the new deployment works as expected. - Execute the cutover — switching webhook endpoints, DNS, Shopify app URLs, or any other relevant routing — in a way that produces zero downtime or operational disruption. - Verify all Shopify connections (webhooks, OAuth, app proxies, POS UI extension registration, etc.) are correctly wired to the new hosting after cutover. - Document the new deployment so I have a clear record of where each app lives, how it is accessed, how the environment is configured, and how to maintain it going forward. WHAT I AM NOT LOOKING FOR - No new features. - No code refactoring. - No "improvements" to the apps. - No exploratory audit or rebuild. - The apps work. They just need to live somewhere else. If you see something in the codebase you'd genuinely recommend addressing, flag it to me separately — but do not change it as part of this engagement. Migration first, anything else later, only if I ask. WHO YOU'LL BE COORDINATING WITH This migration involves three parties: 1. You (the migration contractor). 2. My current development team (who will provide source code and deployment details). 3. Me (overseeing the engagement and approving the cutover). You will need to be comfortable coordinating with my current developers professionally to obtain what you need from them. The relationship is winding down, but the handover should be cordial and efficient. I will introduce you to them directly once we have an agreed scope and timeline. WHAT I'M LOOKING FOR IN A CONTRACTOR - Strong experience with Shopify custom apps (private apps, public apps, app extensions, POS UI extensions). - Strong experience with cloud hosting and deployment (Render, Heroku, AWS, DigitalOcean, or equivalent). - Experience with zero-downtime migrations and parallel-deployment cutover patterns. - Comfortable working with code you did not write and deploying it without making changes. - Direct, honest communication style. I do not need to be managed or shielded — I just need clear updates and reliable execution. - IP ownership: all deployment configuration, hosting accounts, environment variables, and documentation produced under this engagement belong to me. QUOTE AND PROPOSAL Please provide: - A fixed-price quote for the full migration as described above. - Your recommended hosting environment and rationale. - An estimated timeline from kickoff to cutover. - A brief description of your relevant prior experience (Shopify app migrations, hosting transitions, or similar). - Any clarifying questions you have before quoting. Looking forward to hearing from you.