The Story
Your trip planner is humming along. Users sign up, generate itineraries in the background with nice progress indicators, and everything feels smooth. You’re getting real users now. Things are good.
Then someone goes on vacation.
They come back with 20 photos from their trip to Barcelona. They want to add them all to their trip — the Sagrada Familia, the tapas bar, the sunset from Park Guell, all of it. Your app has an upload button. They select all 20 photos. Click upload.
And your server explodes.
Not literally. But effectively. What happens is this: your server receives 20 photos at once and tries to do everything simultaneously. Resize photo 1 while resizing photo 2 while resizing photo 3 while analyzing photo 4 with AI while saving photo 5 to storage while… you get the picture. Twenty parallel operations, each one chewing through memory and CPU.
Your server has limited resources. Trying to process 20 heavy operations at the same time is like asking one person to carry 20 grocery bags in a single trip. They might get two steps out the door before everything hits the ground.
But it gets worse. While your server is drowning in one user’s 20 photos, another user tries to generate a trip. Their request sits in line behind all that photo processing. They see a spinner. They leave. One user’s upload just ruined the experience for everyone.
This is the photo flood. And the solution is something you encounter every single day in the real world: a queue.
This lesson continues with the full course
The story intro above is free to read. The full lesson — prompts, explanations, and adapt-it exercises — requires the Build It Right ($149) tier or above.