Polymorph YC Application

Winter 2026Active

Polymorph went through Y Combinator in the Winter 2026 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 2026
Industry: B2B
Team size: 3
Status: Active
Launched: 2026

Founders

Andrew SyFounder

What Polymorph does

Polymorph is personalization infra that lets developers use AI to personalize their apps, improving conversion, LTV, and CAC for consumer and self-serve apps. This infra is used to personalize user experiences and notifications, which takes whole orgs years to build at companies like Facebook, TikTok, and Google. They already support over 3.5M users across our customers, with some seeing 3.6x increases in conversion rates after using Polymorph. Users are unique and special, make them feel like it~ The team has extensive experience in the space, having been in senior engineering leadership at Meta Ads, building out large-scale ML infrastructure at Scale AI, and iterating quickly and securely at startups like Gusto, Opal, and Nira.

Polymorph's YC application, reconstructed

Y Combinator application

Polymorph, Winter 2026 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

Polymorph

Describe what your company does in 50 characters or less.

Personalization infra that improves retention, LTV, and CAC

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

We build personalization infrastructure that lets developers use AI to tailor user experiences and notifications in their apps. Our product simplifies what takes big companies years to build, helping consumer and self-serve apps increase conversion, retention, and lifetime value by making users feel uniquely valued.

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

We live in San Francisco and intend to base Polymorph here after YC as well.

Explain your decision regarding location.

San Francisco has the tech talent and startup ecosystem we need. All three founders are already based here, so it makes sense to keep the company in a place where we can easily recruit and operate.

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 Polymorph YC application?

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