Simplify I/O slide: remove flow diagram, add concurrency punchline

Torey Heinz committed Feb 17, 2026
commit 4698e5b5613ca4fc44fe25c5d06c287d1d9336d4
Showing 1 changed file with 5 additions and 17 deletions
slides/01-intro.html +5 -17
@@ @@ -228,28 +228,16 @@
<!-- SLIDE 10: Why It Matters — I/O bound insight -->
<section data-auto-animate>
<h2>Why It Matters for Web Apps</h2>
- <p>The key insight: <strong>Web applications are fundamentally I/O bound</strong></p>
-
- <div class="flow-diagram" data-id="flow">
- Request arrives
- |
- [ Parse ] &larr; microseconds
- |
- <span class="waiting">[ Query DB ]</span> &larr; <span class="waiting">WAITING (ms to seconds)</span>
- |
- [ Process ] &larr; microseconds
- |
- <span class="waiting">[ Call API ]</span> &larr; <span class="waiting">WAITING (ms to seconds)</span>
- |
- [ Render ] &larr; microseconds
- |
- Response sent
- </div>
+ <p><strong>Web applications are fundamentally I/O bound</strong></p>
<p class="fragment small" style="margin-top: 0.5em;">
Your app spends most of its time <strong>waiting</strong> &mdash; on databases, APIs, file systems.
</p>
+ <p class="fragment" style="margin-top: 1em;">
+ The answer to I/O bound problems? <strong>Concurrency.</strong>
+ </p>
+
<aside class="notes">
Here's the insight that made Elixir click for me. Think about what your web app actually does. The computation — parsing, processing, rendering — takes microseconds. But the I/O — database queries, API calls — takes milliseconds to seconds. Your app spends almost all its time waiting. So the question is: how well does your runtime handle waiting?
</aside>