Design Engineer

About the role

Manifest OS is an AI-native company on a mission to replace the billable hour and make legal services more accessible for American businesses and consumers. We power the next generation of AI-native law firms with one unified global brand, a proprietary technology platform, and a centralized back office — enabling lawyers to eliminate the administrative burden and focus on delivering exceptional outcomes for their clients. Manifest OS has raised a $60M Series A from Menlo Ventures, Kleiner Perkins, First Round, and Quiet Capital.

Responsibilities

• Design System Engineering: Evolve the design system into scalable components and tokens that make every project fast to ship and beautiful by default, whether a person or an agent is building it. Spot patterns that keep recurring across the platform, and promote them into tested, documented primitives that designers and engineers can compose without reinventing. Build the guardrails that keep the product on-system as it scales, including token linting, visual regression testing, and component documentation that AI coding tools can read and follow.
• Frontend Architecture: Translate the design system into components and tokens that make the next screen fast to ship and beautiful by default, by a person or an agent. Partner with design on what AI-native interfaces should be in a high-stakes domain: progressive disclosure, streaming states, and the patterns nobody's figured out yet. Define the contracts between backend and UI - data fetching, caching, state boundaries, the choices that make the design hold up against real data. Own the screens clients and attorneys live in, where a well-set page turns a dreaded process into one that actually feels good to use. Build loading, empty, error, partial, and permission-restricted states as first-class parts of every feature, so nothing ships with only the happy path. Treat accessibility, performance, and failure recovery as acceptance criteria, not polish. A failed document upload the night before a filing deadline should tell the user exactly what happened and what to do next.
• Product Engineering: Own end-to-end features across our legal tech platform - client portals, case management, and the workflows lawyers and clients depend on daily. Design production-grade APIs, data models, and permission systems for a regulated, high-trust domain.
• Agent Platform: Eval systems, retrieval, and agent orchestration - building the infrastructure that measures and improves how our AI agents perform. Harness engineering - building the tooling and guardrails that let the rest of the company build securely, reliably, and self-serve.

Requirements

Must-haves

• 7+ years building production software, with demonstrated depth in at least one area (backend systems, infra, ML/AI systems, frontend or similar)
• Built or meaningfully shaped a production design system, including component APIs, tokens, theming, and documentation, that other engineers adopted and shipped with
• Proven track record delivering features that produce measurable business outcomes
• Comfort with relational database design and data modeling
• Hands-on experience deploying and operating services on a major cloud platform
• Fluent with AI coding tools as a core part of your daily workflow
• A track record of self-teaching your way into unfamiliar systems and shipping there
• First-principles and systems thinking: you can reason about a system you didn't build, from the database up through the API to the product surface
• Familiarity with our stack - TypeScript, React, GCP, PostgreSQL

Nice-to-haves

• Experience making a design system legible to AI coding tools, through machine-readable documentation, token linting, or visual regression testing that keeps generated UI on-system
• Deeply engaged with the AI tooling ecosystem - you follow new model releases, experiment with new tools as they land, and stay current out of genuine curiosity
• Experience with eval systems, retrieval, agent orchestration OR ML in production
• Background building client portals, CRMs, or case management systems
• Familiarity with legal tech or other regulated industries

Schedule

This is an in-person role - you'll be on-site at our NYC office 5 days a week.