Ask HN: How do you market a developer tool?

Hi HN, I build and run a developer tool which helps teams deliver products faster by allowing front-end devs to mock REST APIs easily, without needing to wait for the backend guys to get things ready. It has a few features my own team finds very useful (ex: a single person can mock a server and share it to the entire team, and updates then get synced automatically etc.) which reduce the overhead of maintaining the mock in sync with the actual API being built.

The product is split into an Electron app (fairly performant), and a web service which allows for teams to be created and mocked APIs shared.

So far, I've had an abysmal time marketing the service. My marketing strategy so far has been:

1. Posting to HN, Reddit (r/programming and r/programmingtools), Product Hunt, IndieHackers - Bad initial traction (the post on HN got buried), very few signups, quite a few downloads of which about 5% stuck around and still use the app.

2. Posting as a response to appropriate questions on stackoverflow - The four answers I wrote still net me about 10 visits a day.

3. Blogging on the official product blog - Pretty much nobody reads this, I've tried cross posting to r/programming but generally not very receptive over there.

That said, based on my own teams usage, and the usage of a few teams we have gotten to use through word of mouth is quite positive and it has quickly become an integral tool. So I'm not really willing to give up on it yet.

So how should I get more developers to try out and use the tool? How do I market this tool to developers? Should I be trying to go after Engineering Managers instead?

Thanks in advance for your help.

EDIT: It's called Mocktastic. (Site: https://mocktastic.com, Blog: https://blog.mocktastic.com)