Kunjal Singh

Founding designer, rumik

jan-oct, 2026

Rumik Playground is for everyone, not just developers.

Playground is rumik's flagship platform to create agents, generate voice using tts, and creating api keys.

I launched the rumik playground as the product owner, designing and coding how the platform worked, looked and behaved for different users and states.

Users blamed the models for audio their prompts caused.

There was no easy way to create and connect tools and variables, and required going through multiple documentation pages, or prompting an llm.

The platform should guide the user to get the best possible output from the model and agents without any documentation.

90% of the users didn't want to read the prompting guide beforehand, and just wanted to start building.

Users who deployed an agent successfully reached out 100% more to discuss pricing, and enterprise options.

Key decisions

1)how to make empty and default states helpful?

2)Block bad prompts, or warn?

3)What should the guide lead with?

4)Should the tools and variables be global or per agent?

5)What should be defined in a tool?

6)How does a variable get its value?

7)How will we know it worked?

questionsfirstevery start,one endone user,any loginone event,one meaningno silentrevenue gapsannotatechangesfix the bugbehind the datatag thesource

Outcome

Shipped five fixes with one rule, teach in place, warn, don't block, each instrumented before launch.

  • 8 of 8existing events tracked only success. I rebuilt them from business questions
  • 17%of generations had no recorded outcome. Now every start has one end
  • 20lifecycle emails, designed to know when to stop