đŸ”„ The DB Grill đŸ”„

Where database blog posts get flame-broiled to perfection

Circles Uses MongoDB to Fuel Jetpac’s Rapid Global Expansion
Originally from mongodb.com
September 11, 2025 ‱ Roasted by Alex "Downtime" Rodriguez Read Original Article

Alright, settle down, everyone. Grab your free vendor-branded stress ball. I just finished reading this... visionary piece of future-journalism from MongoDB about Circles. And let me tell you, my pager is already vibrating with phantom alerts just thinking about it. This isn't a case study; it's a pre-mortem, and they've handed us the full report.

First off, the interview is dated July 2025. They’re writing marketing copy from the future. I love that. It’s the same level of optimistic delusion that leads a team to believe a six-week migration project won't have any “unforeseen complexities.” Bold. I’ll give them that.

So, our hero is Kelvin Chua, the "Head of Markets." Not Head of Engineering. Not SRE Lead. Head of Markets. Perfect. The guy in charge of selling the thing is telling us how robust the engine is. That's like the marketing director for the Titanic telling you about the ship's "unprecedented structural integrity." What could possibly go wrong?

He tells us his journey with MongoDB began in his startup days, choosing it to handle "5 million documents per hour." That’s the classic developer origin story. It translates to: "I was using Node.js, I didn't want to write a schema, and this thing let me just throw JSON at it until it stuck." It's the "move fast and break things" approach, except my team is the one that has to glue the "things" back together with duct tape and despair.

The real gem is the Jetpac project. A "massive challenge" to build a global travel product from scratch in six weeks. Six weeks. I’ve had root canals that took more planning. They didn’t build a product; they assembled a tech-debt Jenga tower and are praying no one breathes on it too hard. They chose Atlas because they had no time to think, and now they’re calling that frantic scramble a "strategy."

But let's get to my favorite part: the justification for migrating from their self-hosted mess to the shiny managed service. Let me translate this from Marketing-speak into Operations:

And this line, this absolute work of art:

We were able to shortcut our process by about a week just because contractors could access MongoDB Atlas and select schemas immediately—no delays in consulting environments!

Oh, fantastic. No pesky change control, no DBA review, no guardrails. Just contractors YOLO-ing schema changes directly into the managed environment to "move faster." What is monitoring? What is an alerting strategy? Don't worry about it! The charts on the Atlas dashboard are green, so everything must be fine. I'm sure they have a comprehensive observability stack and they're not just waiting for the support tickets to roll in. I'm sure of it.

And now, the grand finale: AI. They're bolting on vector search for RAG projects. Bless their hearts. They took their "aggregated," cost-optimized clusters—the ones now running a dozen formerly separate workloads—and they're going to start hammering them with vector similarity searches. You know, the kind of notoriously resource-intensive queries that have a habit of consuming all available CPU and memory.

I can see it now. It'll be 3:15 AM on New Year's Day. The Head of Markets will be sleeping soundly, dreaming of 500% growth. But I'll be awake, staring at a Grafana dashboard that’s a solid wall of red. The cause? A new, poorly-indexed AI-powered "personalized offer" query will be running a full collection scan across billions of documents, locking up the entire primary node. The "aggregated" cluster will fall over, taking every single one of their "revolutionized" services with it. Their "seamless roaming" will be anything but, and thousands of holiday travelers will be stranded without data, lighting up Twitter with our company's name.

My on-call engineer will be trying to explain to me why they can't fail over because the read replicas are also choked, trying to catch up with an oplog that's growing faster than the national debt. And I’ll be sitting here, sipping my cold coffee, looking at my laptop lid. I'll peel off the backing of a fresh MongoDB sticker and place it gently on my wall of fame, right next to my faded ones from RethinkDB, Parse, and all the other "revolutionary" databases that were supposed to solve all our problems.

Thanks for the story, Kelvin. It’s a good one. I’ll think of it fondly when I'm canceling my holiday plans.