Shaping the Impossible: Production-Ready CustomPainter Techniques

When we start with Flutter, widgets feel like magic. They cover most of our use cases—until one day the design team comes up with something that just doesn’t fit inside the widget box. That’s when CustomPainter enters the picture.

In this talk, I’ll share how CustomPainter gives you complete control over the canvas and allows you to create visuals that are simply not possible with standard widgets. I’ll walk you through how I used it in a real production feature—from drawing and manipulating paths to converting an SVG into custom path data. Along the way, we’ll also touch on some simple vector concepts that make life easier when working with shapes and curves.

The goal is not just to show cool graphics, but to teach you how to structure your drawing logic, how to keep performance in mind, and how to break down a complex idea into smaller, manageable pieces. By the end, you’ll feel confident about picking up CustomPainter the next time your app’s design demands something unique.

I’ll also walk through my experience of implementing CustomPainter in the AMEX Lounge app, where we had to design premium card visuals and dynamic graphics that demanded pixel-perfect accuracy. From breaking down complex drawings into smaller reusable parts, to ensuring smooth performance on high-density screens, you’ll learn what it really takes to use CustomPainter effectively in production.

This session is not just about code—it’s about building confidence to pick up CustomPainter when your design vision doesn’t fit inside a widget box.

Key Takeaways

- Clear understanding of how CustomPainter works and when it makes sense to use it.
- Step-by-step process of turning SVG paths into Flutter-friendly drawings.
- Easy-to-grasp vector basics that you can apply in your own code.
- Practical tips on breaking complex drawings into smaller, testable parts.
- Ideas and inspiration to go beyond widgets and build interfaces that stand out.