About this Senior Frontend Engineer role at Deuna
About the role
We built Athia, DEUNA's cognitive intelligence layer for payment optimization and fraud detection. You'll own the interfaces where that intelligence meets the user: conversational copilots, agentic "deep research" flows, organic dashboards, and live data visualizations. This is high-craft product engineering — we move from a PM's idea to a working, shippable flow in days, then harden what proves out. You should love turning product definitions into interfaces that feel fast, trustworthy, and a little magical.
You'll work close to product and design (sometimes you are the designer for a flow), and you'll have enough backend range to wire your own data and APIs without waiting on someone else.
What you'll do
Build and maintain production-grade Next.js (App Router) + React + TypeScript applications — dashboards, chat/copilot surfaces, and agentic research UIs.
Design and ship data visualizations (time series, breakdowns, combo charts, KPI strips) with a charting library (we use ECharts) — readable, performant, on-brand.
Craft AI/agent UX: streaming "thinking" traces, multi-step/agent fan-out progress, grounded follow-up conversations, and the rich result artifacts (boards, reports, canvases) users interrogate.
Own and extend a design system — design tokens, reusable components, motion/animation, and accessibility — keeping a large surface visually consistent.
Prototype mock-first for rapid product iteration, then graduate proven flows to real data and APIs.
Care about performance and correctness: React rendering, SSR/hydration, bundle size, and the subtle bugs that come with modern React.
Do light fullstack glue: build and consume REST/JSON APIs, wire up a backend service or BFF endpoint, shape data contracts, and integrate LLM/agent backends.
Keep the codebase healthy: typed, linted, documented, and easy for the next person (human or AI agent) to pick up.
What you'll need (must-have)
3+ years building web apps with React and TypeScript in production.
Strong with a modern React framework (Next.js or similar) — App Router, SSR/CSR trade-offs, data fetching, routing.
Real fluency in CSS / a utility framework (Tailwind) and translating design into pixel-faithful, responsive, accessible UI.
Experience with data visualization / charting and making dense information legible.
Solid product instincts — you make sensible UX decisions independently and sweat the details (states, empty/loading/error, motion, micro-interactions).
Comfortable with Git, code review, and shipping iteratively; you write code that reads like the code around it.
Basic Fullstack
You can stand up and consume an API — Node/Express or Python/FastAPI — and reason about request/response shapes, auth, and async behavior.
You're comfortable integrating LLM / agent APIs (streaming responses, tool/function calls) and modeling that on the frontend.
You don't need to be a backend specialist — but you shouldn't be blocked waiting for one.
Nice to have
AI-native UX experience: copilots, RAG/agent interfaces, streaming/token-by-token UIs, or "show your reasoning" patterns.
Building or maintaining a design system / component library.
Fintech / payments domain exposure (acceptance rates, routing, fraud, PSPs) — or eagerness to learn it fast.
Animation/motion craft (Framer Motion, CSS transitions, tasteful micro-interactions).
Working alongside AI coding agents and keeping a repo that's legible to them (clear conventions, docs, typed contracts).
An eye for performance profiling and React rendering optimization.
How we work
Speed-to-working-flow beats premature robustness — we prototype to learn, then invest where it counts.
Tight loop with PM and design; you'll often shape the experience, not just implement it.
Small surface area of ownership, high autonomy, high craft bar.
