https://www.pistack.xyz/tags/rules/ Recent content in Rules on Pi Stack Hugo en-us Wed, 04 Nov 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-11-04-mvel-vs-jexl-vs-aviatorscript-jvm-expression-languages/ Wed, 04 Nov 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-11-04-mvel-vs-jexl-vs-aviatorscript-jvm-expression-languages/ <p>The moment a Java application lets a non-developer change behaviour, you inherit an expression language problem. Pricing rules, discount thresholds, alert conditions, feature gates, routing decisions — someone always wants to edit them without a deploy. The first version of that feature is always <code>if (tier.equals(&quot;gold&quot;) &amp;&amp; total &gt; 300)</code> buried in a service class. The fifth version is a <code>switch</code> statement nobody dares touch, and the sixth version is an expression engine.</p>