Senior AI Frontend Engineer

HeyDaily Inc.; San Francisco, Northern (CA, KY); Hybrid; USD 180,000 - 240,000; Full time

Job summary

HeyDaily Inc. in San Francisco seeks a senior frontend engineer to own Sauna's frontend, delivering fast, polished interfaces and tackling complex data fetching and state management. You’ll make design calls, prototype quickly, implement or create designs, and collaborate with product and design.

Stack includes TypeScript, React, Tanstack, Zustand, TailwindCSS, IndexedDB, Cloudflare Workers. If you love crafting great UX, performance, and autonomous decision-making, join a team backed by Spark

Qualifications

• 4+ years of frontend engineering with shipped web apps.
• Strong React expertise and state management knowledge.
• Ability to own full-stack features (DB, backend route, frontend UI).
• Product sense to sketch and ship intuitive interactions.
• Focus on performance, caching, and snappy UX.
• Own UX decisions and deliver clean, reusable components.
• High autonomy with a bias toward shipping and iteration.

Responsibilities

• Own the frontend of Sauna, shipping fast, intuitive interfaces.
• Make design calls, prototype quickly, and implement or create designs.
• Collaborate with product and design to ship features end-to-end.

Skills

Frontend engineering

React

State management

Performance

Autonomy

Product sense

Tools

TypeScript

Tanstack

Zustand

TailwindCSS

IndexedDB

Cloudflare Workers

Job description

Please read first

• This is a full-time, in-person role based in San Francisco (Presidio) - we work from the office 5 days a week.

• You must be based in the Bay Area or willing to relocate before starting.

• We require US work authorization , but are open to O-1 or J-1 visa sponsorship for exceptional candidates.

About Sauna by Wordware

Every tool you use was built as an island, so you became the glue between them: a name from Gmail into the CRM, a time from the CRM into Calendly, a note from Calendly into a doc. AI showed up and mostly became an eleventh window to paste into.

Sauna is a hybrid of AI and software standing on one shared brain. It holds your context and hands you real software built on top of it, so an ordinary Calendly becomes one that writes the invite itself and knows which of your busy hours bend, and for whom. Software for the path you repeat, AI for the edge that never repeats.

Wordware is the team behind it, 15 people backed by Spark Capital, Felicis, and Y Combinator with a $30M seed, the largest in YC's history. We build from an office in the Presidio, fifty metres from Crissy Field beach, and we work absurdly hard because we can see and feel the outcome every day.

About the Role:

You’ll own the frontend of Sauna: shipping interfaces that feel instant, intuitive, and polished even when the underlying work is complex.

What You’ll Do:

You’ll need to make product and design calls yourself, prototype quickly, and execute without waiting for perfect specs. Sometimes you’ll implement designs. Other times you’ll create them.

Stack: TypeScript, React, Tanstack, Zustand, TailwindCSS, IndexedDB, Cloudflare Workers.

Who You Are:

Minimum:

• 4+ years of frontend engineering with a portfolio of complex web apps you’ve shipped. We want to see multiplayer experiences, apps handling large data with sophisticated fetching and caching, or work with server-sent events (SSE).

• You love React and deeply understand state management. You know when to useMemo, how callbacks work, the component lifecycle, and you write beautiful, reusable components. You recognize when props are being drilled through multiple layers and should be lifted into context or Zustand instead.

• You’re comfortable owning a full-stack feature. You can do the DB migration, write the route in the backend, fetch on the frontend, and create the UI for it.

• Product sense and design intuition: you can take a rough product direction, sketch an interaction, and ship something that feels right.

• You care about performance. You know when to cache, when to refetch stale data, and how to optimistically update the UI. You notice duplicated network requests. You care about the app feeling snappy and responsive.

• You make design decisions: you’ll need to own some UX decisions, create simple designs when needed, and unblock yourself.

• High autonomy, low ego: you don’t wait for permission or perfect specs. You ship, gather feedback, and iterate.

• You care about craft: details like loading states, empty states, error messages, keyboard shortcuts. The 1000 small decisions that make software feel good.

Bonus (but not required):

• Experience with multiplayer apps (Y.js, Automerge, CRDTs, or similar real-time collaboration frameworks).

• Built interfaces for LLM-based tools (streaming responses, handling uncertainty, progressive disclosure).

• Experience with local-first architectures (IndexedDB, service workers, sync strategies).

• Design background or strong visual sense: you can make things look good without a designer.

• Been a founding frontend engineer and established standards from scratch.

Compensation & Benefits:

Base salary: $180K–$240K + meaningful early-stage equity + health, dental, 401(k), considerable PTO, gym budget, lunch.

The Process:

We keep our process simple. Exceptional candidates go from first touch to offer within 2 weeks.

• 2. 15-minute intro call: Align on location, motivation, and logistics. If it's a go, we move fast from here.

• 3. System design interview: A deep dive into how you think and architect systems. We'll walk through a real Wordware problem together.

• 4. Final conversation: We answer your questions and scope out the work trial.

• 5. Work trial: Paid, in person, usually a few days to two weeks. You work on a real project with us. See how we work, see if it fits, both sides.