Add lightning talk about JGit racy reads

Change-Id: I221bef1666af85ff54f2143ea041d55c35ba3aa5
diff --git a/lightning-talks/jgit-racy-read.md b/lightning-talks/jgit-racy-read.md
new file mode 100644
index 0000000..ee4c13c
--- /dev/null
+++ b/lightning-talks/jgit-racy-read.md
@@ -0,0 +1,6 @@
+# Racy JGit - a short history of time
+
+Git uses file meta-data to avoid it has to read file content for detecting modifications.
+This seems a simple idea but getting the Java implementation in JGit right was a lengthy endeavour.
+
+*[Matthias Sohn, Gerrit Contributor and Community Manager](../speakers.md#msohn)*
diff --git a/schedule-usa.md b/schedule-usa.md
index 4397e98..3833b66 100644
--- a/schedule-usa.md
+++ b/schedule-usa.md
@@ -64,7 +64,7 @@
 | 14:45 | [Gerrit upgrades, step-by-step](sessions/gerrit-upgrades-step-by-step.md)                    |
 | 15:30 | [Using Zuul CI for the Gerrit Code Review project](sessions/zuul.md)                         |
 | 16:15 | Break & Networking                                                                           |
-| 16:30 | Lightning talks <br/>- [Show me your dashboard - 10'](lightning-talks/show-me-your-dashboards.md) <br/>- [Gerrit UX @ Google - 15'](lightning-talks/google-gerrit-ux.md)
+| 16:30 | Lightning talks <br/>- [Show me your dashboard - 10'](lightning-talks/show-me-your-dashboards.md) <br/>- [Gerrit UX @ Google - 15'](lightning-talks/google-gerrit-ux.md) <br/>- [Racy JGit - a short history of time - 15'](lightning-talks/jgit-racy-read.md)
 | 17:30 | End of Day 1                                                                                 |
 | 19:00 | Dinner - Celebrations for Gerrit v3                                                        |
 
diff --git a/speakers.md b/speakers.md
index f917cb5..4743102 100644
--- a/speakers.md
+++ b/speakers.md
@@ -138,4 +138,7 @@
 Before working in Git, Ivan worked for Nokia in their linux-based mobile
 platform, Maemo/Meego, and has contributed to the GNOME desktop.
 
+### Matthias Sohn - SAP {#msohn}
 
+Matthias is a long-time Gerrit contributor. He joined the Gerrit project in 2010,
+and assumed the role as community manager in 2019.  He leads the Gerrit team at SAP and is project lead of Eclipse JGit and EGit.
\ No newline at end of file