Building it
In early 2024, MGM guests who didn't use the mobile app had no way to check in online, so most of them waited in line at the front desk. I was asked to build a web version, and I started it from an empty repository in January.
I built most of the first version myself. Guests could find their reservation, choose an arrival time, verify their ID, add a payment card and confirm, all from a browser. I set up testing and automated deployments in the first week, which made it safer to move fast against a tight deadline.
Shortly before launch, the app kept losing the guest's card details between pages. When I tracked it down, the cause wasn't in our app: every web app on MGM's platform was reloading the whole page on navigation. I worked around it so we could launch, and the first property went live about three months after I started.
Growing it
After the pilot, we added features that brought in revenue, like room upgrades and paid add-ons such as early check-in. We also opened the flow to guests who booked through third-party sites like Expedia. Today more than 1 in 8 completed check-ins come from those guests, who previously couldn't check in online at all.
Rather than launching everywhere at once, we used feature flags to turn check-in on one property at a time. That let us handle each property's branding and setup separately, and fix problems before they reached every guest. One rollout day did go wrong, and we rolled back and re-released within a few hours.
Today web check-in runs at more than 20 MGM properties, and about 50,000 guests a month complete it.
Leading it
In 2025 I became the web lead, and four engineers took over most of the feature work. My job changed from writing most of the code to helping the team do their best work: detailed code reviews, careful feature-flagged releases, and clearing whatever was blocking them.
Together we shipped three major features. Multi-room check-in lets a guest check in several rooms at once. An embedded payment form keeps raw card details out of our app entirely. One-step MGM Rewards sign-up reached about 2,600 sign-up starts a month within two months of launch.
The biggest lesson came from a mistake. I added analytics to track where guests dropped off, then found it had recorded nothing because of a platform change I hadn't noticed. I fixed it, and since then I check real usage data after every release instead of assuming that something shipped means it works.