Product Designer (UX/UI)

Silmaril

Security for agents that self-improves.

We are backed by Y Combinator and based in San Francisco.

The Opportunity

You will shape how people understand, trust, and control autonomous agents, and how agents discover, understand, and use Silmaril.

You will have broad ownership across product strategy, UX, UI, and brand. Work directly with the founders and engineers, taking ideas from customer research and early exploration through prototypes, production, and iteration.

This is foundational work: you will help establish the design language of a new product category and the standards Silmaril grows around.

Human Design

We believe human design matters more than ever as software becomes easier to produce.

We are looking for exceptional taste, empathy, and original thinking. You can challenge a brief, identify the underlying problem, and make deliberate choices about how a product should work and feel.

You care about the details, from the structure of a workflow to the wording of a label. You know how those choices combine into an experience people understand and trust.

AI can support your productivity. Your ideas, visual direction, and design decisions come from your own observation, exploration, and judgment.

Agent-First Design

We want to build a product that agents love to use.

Treat agents as users with their own needs: discoverable capabilities, clear instructions, predictable interactions, useful context, and precise feedback.

Your canvas extends beyond screens to tools, documentation, and the information agents receive. Great agent-first design also gives people a clear view of what an agent is doing and meaningful control over its behavior.

You Will Own

Product and research

Work directly with customers to identify important problems, test ideas, and shape product direction.

UX and interaction

Design clear paths through onboarding, investigation, policy, approval, and action. Help people delegate work, inspect decisions, and intervene with confidence.

UI and visual craft

Set an exceptional standard for typography, layout, hierarchy, and interaction. Make complex information easy to understand and act on.

Agent experience

Design how agents discover capabilities, use tools, understand permissions, interpret results, and recover from failures within clear boundaries.

Prototypes and production

Build prototypes that test real questions. Partner with engineering to ship, refine, and own the experience in use.

Design systems

Create coherent components and patterns, including accessible interactions, responsive behavior, and complete loading, empty, and error states.

Brand and communication

Shape Silmaril’s identity across the product, website, demos, and customer materials.

You

• You have three or more years of professional product design experience.
• You have shipped complex products with a high bar for design and engineering.
• Your portfolio shows original thinking, strong visual craft, clear interaction design, and your personal contribution to what shipped.
• You can turn an ambiguous problem into research, product direction, prototypes, and a polished production experience.
• You make technical systems understandable and are curious about designing for agents as users.
• You work closely with engineers, test your assumptions, and take responsibility for the experience in real use.
• You want broad ownership and to build in person with a small, exceptional team in San Francisco.

Bonus

• Experience with security products, developer tools, enterprise software, AI interfaces, or agent workflows.
• Experience building design systems, distinctive brands, or products from the ground up.
• Strong interactive prototyping skills or an understanding of frontend implementation.