Boundary YC Application

Winter 2023Active

Boundary went through Y Combinator in the Winter 2023 batch as a B2B company. Below: what the company does, who founded it, and its application to YC, reconstructed question by question in the real YC form.

YC batch: Winter 2023
Industry: B2B
Team size: 10
Status: Active
Launched: 2023

Founders

Vaibhav GuptaFounder
Aaron Villalpando GonzalezFounder

What Boundary does

Boundary is building BAML -- a programming language to build AI agents. We used to code in assembly, and moved on to C. From C, we moved on to higher level languages like Python. Now we are going from Python to natural language. What does the code look like when 50% of the business decisions is decided by an AI agent / prompts? How do you test these AI components? We made BAML to address these problems. BAML helps has built-in tools to test, observe, and work with structured LLM outputs / tool calling natively in the language 10x faster. With BAML you can also instantly parallelize LLM Calls, or react to certain events or changes in your pipelines, without having to write any boilerplate. It's like using 'React' for AI. BAML code can used from any other language -- providing a standardized way to organize and declare any LLM or AI code.

Boundary's YC application, reconstructed

Y Combinator application

Boundary, Winter 2023 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

Boundary

Describe what your company does in 50 characters or less.

The programming language for AI

What is your company going to make? Please describe your product and what it does or will do.

We are building BAML, a programming language designed specifically to build AI agents. It tackles how to code when AI and prompting drive up to 50% of business logic, helping developers test and observe AI components effectively. BAML natively supports structured LLM outputs, tool calls, parallelizing calls, and event-driven pipelines, making AI development faster and more reliable. It also integrates with other languages to standardize AI code organization.

Where do you live now, and where would the company be based after YC?

We currently live in Seattle, WA, and the company will remain based here after YC.

Explain your decision regarding location.

We are based in Seattle where the founders live and where the current team works. Seattle gives us access to diverse AI talent and a good quality of life while building Boundary.

21 more answers in the full application

Founders, Progress, Idea, Equity, Curious, Batch Preference are in the full version. Create a free account to open it in YC Insights, next to every other YC batch.

See full application

Frequently Asked Questions

Is this the real Boundary YC application?

No. Y Combinator keeps submitted applications private. This is a reconstruction: the real YC form questions, answered from Boundary's public data (launch notes, founder backgrounds, product description). It shows how a company like Boundary would present itself to YC, not the text they submitted.