Frontend Engineer

About Us

What we're building

We’re a fast-growing deep-tech company crafting web-based tools that help people model, understand, and optimize real-world systems and processes using AI. From interactive process-model editors to real-time simulations, we turn complex, non-textual data into intuitive, responsive, accessible web apps designed to be used by non-technical domain experts at research labs, startups and enterprises worldwide.

Responsibilities

Own novel frontend UIs

As a senior Frontend Engineer you’ll own end-to-end delivery of novel world modeling and AI native interface components, helping shape our frontend architecture, as part of an Advanced Research + Invention Agency funded project building systems for delivering “Safeguarded AI”. You’ll collaborate with technical product management, UX researchers and AI engineers from top labs, as well as our own developers and leadership, to push the boundaries of what a browser can do — whether that’s a drag-and-drop model builder, timeline-based simulator, or multimodal feedback interface.

What You’ll Do

Day-to-day

Design, build, and ship production-ready React/TypeScript components and app-wide features for complex data-driven UIs
Work with mathematical experts to convert world-modeling theory formalizations into software requirements, and writing tests which ensure implementation correctness
Convert novel UX/UI designs — for new world modeling and AI-interaction features — into performant, responsive and accessible experiences that work across devices
Establish project-wide standards for code quality (e.g. via linting), review and testing, and provide feedback on the work of other frontend engineers
Profile and optimize rendering performance for complex interactions and visualisations
Tell the story of best practices and lessons learned in developing and testing novel, complex world-modeling interfaces, e.g. via blog posts and workshops
Partner with backend/infra teams to identify and manage interdependencies, and to help define robust APIs that support excellent, feature-rich frontend performance
Stay on top of emerging browser capabilities and drive adoption of the ones that matter

Requirements

Must-haves

Expertise with React, TypeScript, modern HTML & CSS
Proven track record architecting and delivering rich web apps that involve complex user interactions
Rigorous approach to documenting and versioning components for external audiences
Experience profiling and debugging performance in devtools
Comfortable taking a visible technical leadership role, mediating discussions around standards and implementation approaches, and taking accountability for the delivery of features on time and to spec
Excellent written & verbal communication in English and comfort working async

Nice-to-have

Familiarity with process/model-oriented UIs: BPMN, UML, systems-dynamics models, graphs, etc.
Understanding of WCAG 2.2 and pragmatic accessibility techniques (ARIA, focus management, keyboard UX)
Public record of maintaining a well-documented, semantically versioned library (ideally in an open-source context)
Experience with CRDTs or other real-time collaboration solutions
Hands-on experience with WebAssembly pipelines
Canvas/WebGL experience for high-performance rendering

Our mission

Overcome bounded rationality

Learn more about our mission →

Our culture

Intense by design

We're focused on building something big, in the service of something important (our mission). To that end, we're unapologetically excited. Actions speak louder than words, and we measure performance by output. You can work from wherever, but we know that teams are more productive together, in-person. We prioritze speed, and measure product delivery timelines in hours and days, not months and years. We value high-energy, high-expectations people who do what they say and say what they mean.

Our benefits

Life at HASH is good

We provide leading equity-weighted total comp, and depending on your location also offer:

Competitive salary and meaningful equity
Tax-advantaged options (e.g. EMI in the UK)
Employer pension contributions
Unlimited holiday
Quarterly in-person team retreats
Gym membership/workout classes
Fully-funded HSA & comprehensive health insurance

Interested?

Let us know you exist

We don’t accept applications to specific roles at HASH, but you can tell us about yourself to make sure you’re on our radar, and share why you're interested in our work. We review every message received, so be sure to include specific examples of relevant experience.