arduino - Why does my circuit work on a breadboard, but not on a perfboard? I am new to soldering

I'm a total beginner when it comes to soldering, and recently I've been trying (and failing) to solder together a simple circuit I put together for a Raspberry Pi sensor.

Although it works fine on the breadboard, when I solder it onto one of my perfboards, the sensor no longer turns on.

Here is a topdown view of my soldered circuit:

Here is a view of the connections (the red block is just covering up old connections from past attempts):

More pictures of the connections.

What might I be doing wrong?

Answer

Everyone here is right. The perf board you are using does not contain the connections between pads like the bread board. If you got rid of the solder mask you would see something like this:

You have to make the connections manually or buy this type of perf board. Notice how it has the connections made in copper?