Senior Frontend Engineer

About Rilian Technologies

Rilian is building Caspian, an event-driven agentic platform that powers next-generation AI and defense applications, designed for environments where access control and resilience matter.

This role is on the team building Meridian, our canvas workspace. It's an infinite, agent-driven surface where an operator works alongside agents on a shared board of live, interactive content. Everything on it persists, syncs in real time across the workspace, and has to stay responsive under pan and zoom. It's the surface where the platform stops being an API and becomes something a person works in.

We're looking for a Senior Frontend Engineer to help own and grow it.

What you'll work on

• Rendering performance on a canvas that mixes ordinary DOM with WebGL-backed content, at boards large enough that naive approaches fall over.
• Managing GPU and memory as finite resources, deciding what renders live, what degrades gracefully, and when.
• Real-time state: keeping every client converged on the same board over a streaming event system, and handling the cases where a client falls behind or a write fails.
• Direct manipulation. Selection, grouping, resize, layering, and the rest of the interactions that have to feel right or nothing else matters.
• The interaction model for working with agents on the canvas, which is as much new design as it is engineering.
• Keeping the architecture legible as the surface grows. We care about this more than most teams do.

Stack
Next.js (App Router) and React 19 in TypeScript. Zustand and TanStack Query for state, RxJS over NATS JetStream for the event stream. Pixi.js for WebGL, ArcGIS for maps. Tailwind and Radix for the design system, Storybook for component work, Vitest for tests.

We're looking for

• Six or more years building production frontends, with real depth in React and TypeScript. You should know how React actually behaves, not just how to use it.
• Performance work you've done yourself. You've profiled your own code, found the real cost, and fixed it.
• Experience with canvas, WebGL, or graphics. Pixi, Three, raw WebGL, or a 2D canvas app you took seriously. You don't need to write shaders, but a scene graph and a camera transform should be familiar.
• Real-time or collaborative state experience. You've built something where "what does the server think is true" was a hard question.
• A preference for simple, testable cores with thin imperative shells, and the judgment to know where that seam goes.
• Clear writing. We expect code to explain the reasoning behind it, and we expect the same in review.

Nice to have

• GIS or mapping work
• Event sourcing, CRDTs, or collaborative editing
• Schema-driven or server-driven UI
• Design systems and Storybook-first component work
• AI-native product surfaces
• Defense, regulated, or otherwise access-controlled environments

Who you are

You care about how software feels to use, and you'll do unglamorous performance work to get there. You're comfortable owning a large surface on a small team, and you'd rather leave a system smaller and clearer than you found it.