Senior Full Stack Engineer

About the role

Inworld recently launched a new platform for consumer AI applications, and we’re looking for an ambitious and capable Senior Full Stack Engineer to join us and take this platform even further.

The new platform has two main components:

• The Inworld Runtime itself, currently available as the npm package @inworld/runtime (and coming to more platforms!). The core concept is specifying AI computations as graphs, but there’s much more.
• Our web experience (and cloud services) that complement the runtime. Internally, we call this web experience the Portal, and you can sign up and try it out yourself at platform.inworld.ai.

You’ll see the major areas currently launched:

• Playgrounds for both the TTS and LLM APIs and TTS zero-shot voice cloning.
• Dashboards/Metrics, Traces, and Logs for viewing the telemetry data generated by the Runtime.
• The Graph Registry feature, which lets you configure and run A/B experiments on your Runtime graphs dynamically, without having to recompile or redeploy code.

As a Full Stack Engineer, you would contribute significantly to both the NodeJS version of the Inworld Runtime, as well as to the Portal web experience. Our teams are small, so there’s plenty of room for you to grow and thrive. Note that our web backends are not written in NodeJS, so this isn’t a conventional full stack role.

In particular, the NodeJS Runtime work is more like systems programming than it is working on a typical NodeJS backend for a web app. Here are some challenges to ponder:

• The core of the Runtime is written in C++, so what is the best way to interop with this code?
• Even though the core is written in C++, there are still challenges on the NodeJS side regarding streaming, concurrency, and high-end scale and performance.
• Providing a first-class, idiomatic developer experience (typing, API ergonomics, best practices, modern libraries, etc).

On the FE side, the key challenges are:

• Shipping quickly. AI is evolving weekly, so there’s a ton of opportunity to be had. We want to move fast to capture those opportunities while they are fresh, full of potential, and exciting with our customers.
• Developer-focused web experience. Our web experience has to be productive and powerful for AI developers (not end-consumers), otherwise they may look elsewhere. This takes listening to customers and iteration as much as just shipping new features out the door. How to do this well is much harder than it seems.
• Great features, solid foundations. Beyond just shipping features, our web foundations need ongoing refinement. Whether it’s state, query handling, routing, hooks, auth, test coverage, etc, there is always room to be better at our basics. We need you to drive such improvements while delivering features on time.

We can’t say in advance what percentage of your time would be spent on FE vs NodeJS work. Every week is different here, and we need someone highly adaptable and comfortable with navigating ambiguity.

This is an IC-focused role. We are looking for someone who loves direct technical contribution.

What you'll do

Whether working on the FE or on the NodeJS Runtime, your goal is shipping useful, high quality features quickly. The more you can own and drive projects, the better. That involves:

• Establishing prioritized feature scope: Collaborate with the PMs, engineers and leads to determine the biggest product needs to focus on now. This is not a one-way flow, please participate with gusto!
• Collaborating, executing, delivering: This is the core of the building loop. We aim to optimize for both speed and quality, despite it being decidedly non-obvious how to manage that tradeoff exceptionally well.
• Reflecting and driving improvements: Advocate for and realize foundational improvements, even while staying busy with feature work.

Expected experience

• Excellent programming skills and experience in JavaScript and TypeScript
• A solid grasp of NodeJS fundamentals: events, the event loop, streams, async, etc.
• Experience developing complex React apps, using popular libraries such as React Router and React Query
• Experience with popular frontend tools and libraries (MUI, Emotion, PostCSS, React Testing Library, Playwright, etc).
• Excellent verbal and written communication skills, can collaborate and coordinate with other roles and engineer with ease, trusted and well-regarded teammate

Bonus Qualifications

• Comfortable with C++ programming.
• Experience with Node interop with C++ code via the Node API.
• Familiarity with Cursor or other AI-assisted coding tools
• Familiarity with turborepo
• Experience building AI-centric web apps and familiarity with AI and ML concepts

Candidates must be based in the SF Bay Area or willing to relocate (you will be working on-site in our South Bay office a few days a week).