---
title: "Design Principles"
description: "4 posts about Design Principles, summarised, each linking to the original."
---

# Design Principles
> 4 posts about Design Principles, summarised, each linking to the original.

## Articles

### [Facebook's Julie Zhuo on product design - The Intercom Blog](https://yomu.fyi/post/facebook-x27-s-julie-zhuo-on-product-design-the-intercom-blog.md)
- Company: [Intercom](https://yomu.fyi/company/intercom.md)
- Published: Oct 13, 2026
- Type: Explainer

Julie Zhuo, Facebook’s VP of Product Design, recounts her evolution from engineering intern to leading design for the core Facebook app, including News Feed and the Like button. She defines good design as an experience that is enjoyable, useful, easy, and accessible, noting that adding functionality without increasing complexity is a persistent challenge. There is no fixed ratio of designers to engineers; the ideal mix depends on the stage of achieving product-market fit. Effective design principles should be controversial, as they articulate why a company made a particular choice over alternatives. When competing products offer similar utility and ease, the ultimate differentiator is the emotional response the product evokes in the user.


### [How we do product design at Intercom – Inside Intercom](https://yomu.fyi/post/how-we-do-product-design-at-intercom-inside-intercom.md)
- Company: [Intercom](https://yomu.fyi/company/intercom.md)
- Published: Oct 13, 2026
- Type: Explainer

In a 2014 email to Intercom’s design team, Paul Adams shares a deliberate ten-step process focusing on deep problem understanding. Designers must first read all research and customer feedback, consult the Customer Success team for clarification, and use product instrumentation to avoid assumptions about user behavior. They are instructed to generate at least three or four different solutions, research how other products solve similar problems, and iterate through feedback from multiple designers. Work proceeds systematically through four design layers: outcome, structure, interaction, and visual, with the principle of not mixing levels and always optimizing for simplicity. After shipping, designers must proactively measure success against defined metrics, talk to the Customer Success team, and learn from mistakes, as truly great designers are dogged in understanding problems even after a solution ships.


### [How users understand new products - The Intercom Blog](https://yomu.fyi/post/how-users-understand-new-products-the-intercom-blog.md)
- Company: [Intercom](https://yomu.fyi/company/intercom.md)
- Published: Oct 8, 2026
- Type: Explainer

Users form different mental models of the same product based on their experiences and assumptions, as illustrated by the “draw toast” exercise where people depict the process in diverse ways. When a product’s system model—how it actually works—aligns with a user’s mental model, the interface feels intuitive; a mismatch causes confusion. To discover these mental models, product teams should talk to users, ask them to draw how they believe the product works, and listen to the nouns and verbs they use. Designers can bridge gaps by employing standard interface patterns (e.g., buttons that behave like buttons), using customers’ own language, and leveraging metaphors like Apple Wallet’s ticket-like appearance or Nest’s dial-based thermostat interface. When a product cannot mirror existing mental models, teams can educate users through tutorials and walkthroughs, similar to video game onboarding, helping customers learn new concepts and quickly grasp the product’s value.


### [Principles of Bot Design: Successful Chatbot Design in 2021 \[+Tips\]](https://yomu.fyi/post/principles-of-bot-design-successful-chatbot-design-in-2021-tips.md)
- Company: [Intercom](https://yomu.fyi/company/intercom.md)
- Published: Oct 8, 2026
- Type: Explainer

The post argues that early chatbot attempts have failed because they over-relied on natural language processing and artificial intelligence capabilities that do not yet exist, often making users feel duped. It presents eight opinionated design principles to guide practical conversational UI development, starting with never pretending to be human. Other core principles include keeping conversations incredibly simple and bounded to particular subjects with linear flows, using structured input like buttons and custom keyboards to avoid parsing errors, and respecting the chat medium by showing formatted card previews instead of raw URLs. The post also emphasizes providing a human escape hatch and optimizing for end-user experience rather than support team convenience, with admin views maintaining full conversation context. Finally, it notes that these principles should be strongly held as a decision-making north star but allowed to evolve as technical possibilities improve.