So first, 300 consistent listens per episode in this area is pretty respectable in my opinion. Niche things like this are more about _who_ is listening rather than how many people.

I'm 100% someone interested in shows like yours, I just didn't know it existed. One major thing you could probably do right away is invite other people with followings in this area as guests. Popular podcasters are generally annoyed by requests to be on their show, but can be a lot more friendly if you invite them on yours. That's because you're doing the work and exposing them to your audience. They'll likely promote it or might even cross post it if you want to. They might have you on as a guest afterwards, someone with that many interviews is bound to have some interesting things to talk about.

The episode you posted as an example of audio quality lately seemed more than good enough for me. As far as burn out, I would maybe recommend actually doing less for each episode, at least until you feel like you can outsource the worst parts. What if you did only the most important parts of post, and cut down post production to an hour instead of 5 or 6? Maybe a tool that auto removes silence, umms and ahs, etc could help a bit here too. Descript for example can do a decent amount of this in about 5 minutes. Good enough in my opinion. Cut out as much post work as you can. I bet you your real audience won't care.

Part of it could also be just shorter recording times. I prefer longer episodes but it seems like I'm the only one. Editing 30 mins of recording is a lot easier than an hour and a half, and people seem more likely to put on shorter episodes (I guess).

Also, just skimming a bit of an episode, I think you overdo the formality of the intro. It sounds too scripted and not like your natural self. Skipping from the intro to a later clip of you speaking, you sound much more natural later on. A lot of people will bail out during the intro if they're just checking you out for the first time and it doesn't hook them much.

The titles should reflect more of what's interesting to the audience, make it the coolest part of whatever they're doing instead of an elevator length description. Are they hitting high requests per second, doing something bleeding edge, serving a lot of users as a solo dev, etc? Combine that with the most interesting part of their stack for the title. Looking at your show notes I can see this stuff is in there, just make it the title.

If you're burning out, try being more selective with guests too. Don't force it. And don't look at it as needing X audience numbers or whatever for success. You're building authority as someone in the industry, getting respect from guests and listeners, being exposed to way more than a normal dev, and so much more. If you're trying to make a living off of the podcast, you'll need to go wayyy more generic and attention grabbing. But I say don't do that. Instead do this thing well and you'll build a name for yourself with the kinds of people who listen to things like this - people in motion, building things, who are excelling in the field. People who are or will be somebody to respect in the industry.Thats a big deal.

Finally, please keep making the show, this is a niche that I've found surprisingly hard to find good content for. I want the technical details, I want the code talk and the deep dive that most podcasts cut out because "people don't want to listen to this". Well, I do and so do plenty of people actually building real things.