diff --git a/src/main.zig b/src/main.zig
index 6e82cc7..9063123 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -17,12 +17,14 @@ pub fn main() !void {
     const alloc = gpa.allocator();
 
     // todo declare or infer module dependencies, topological sort for init order
-    // problem: how to specify runtime options, like Window title?
     // problem: where should gpa go? probably some "Engine" structure in nu.zig
 
     // don't necessarily need to declare topological sort - depth-first traversal
     // of each module's dependencies without repeats would do.
 
+    // idea - use a structure like std.Build.Step where the polymorphic part is a
+    // component of the larger structure.
+
     try nu.Window.init(alloc);
     defer nu.Window.deinit();
 
diff --git a/src/nu/Render.zig b/src/nu/Render.zig
index 952db90..9dcd518 100644
--- a/src/nu/Render.zig
+++ b/src/nu/Render.zig
@@ -92,6 +92,11 @@ pub fn frame() !void {
         for (present_callbacks.items) |cb| {
             cb(cmd);
         }
+
+        // todo really don't like this.
+        // there should be some comptime means for a module to invoke hooks on other modules. eg there should be some
+        // "record" hook that for each module that gets called here; but if the render module is never added then that
+        // hook never gets called
         target.end_rendering(cmd);
         try cmd.endCommandBuffer();