feat: add mathias and antoine talks (#617)

Author: ginifizz

pwa/data/con/2025/conferences/antoine-keynote.md

@@ -5,10 +5,18 @@ track: '1'
 date: '2025-09-18'
 start: '17:20'
 end: '18:00'
-short: TBA 
-tag: 'feedback'
+short: Streamline API Performance with JsonStreamer & ESA
+tag: 'performance'
 ---
 
-# API Platform, JsonEncoder and ESA for a skyrocketing API (🇺🇸)
+# API Platform, JsonStreamer and ESA for a skyrocketing API (🇺🇸)
 
-The topic of the conference will be announced soon.
+When building APIs with API Platform, JSON is king — and Symfony's Serializer is at the heart of it all. But once your API starts returning large documents (think thousands of items), performance hits hard.
+
+This talk explores how to make Symfony-based APIs faster and more scalable. We'll introduce **the new JsonStreamer component**, designed to stream JSON efficiently — perfect for large datasets and real-time delivery. Through simple benchmarks, we'll see how streaming can **dramatically improve memory usage** and time-to-first-byte.
+
+Back in API Platform, we'll look at **how JSON-LD and its complexity introduce new challenges**, and how Symfony JsonStreamer's PropertyMetadataLoader step in to help.
+
+To go even further, we'll look at **ESA (Edge Side APIs)**: a pattern for breaking large JSON payloads into smaller, progressive calls, improving perceived performance and user experience — especially in high-latency environments.
+
+Whether you're hitting performance ceilings or just curious about modern API techniques, this talk will help you rethink how data flows through your Symfony apps.

pwa/data/con/2025/conferences/api-platform-jsonencoder-and-esa-for-a-skyrocketing-api.md

@@ -0,0 +1,18 @@
+---
+type: conference
+speakers: -antoine-bluchet-2025
+track: '1'
+date: '2025-09-18'
+start: '13:40'
+end: '14:20'
+short: Discover API Platform 4.2 Innovations 
+tag: 'feedback'
+---
+
+# How API Platform 4.2 is Redefining API Development (🇺🇸)
+
+API Platform 4.2 marks a major step forward, focusing on developer experience and performance. In this session, I'll guide you through its most impactful new features, all demonstrated on a real-world Symfony application.
+
+We’ll explore the powerful new **Object Mapper**, a Symfony component I created to reduce boilerplate, and dive into the high-performance **Json Streamer** component integration, which reduces memory consumption and improves your API's time-to-first-byte (TTFB). You'll also see how a revamped core—with improved **resource metadata**, powerful new **filters**, and an intuitive **design-first approach**—makes development faster and more robust.
+
+This session goes beyond a feature list to offer a practical guide for building better, more efficient APIs.