Senior Full stack Engineer (L3) - TPV

About the company

OpenFX is a fintech infrastructure startup that provides a stablecoin-native network and API-based solutions for instant, 24/7 cross-border foreign exchange and payments.

About this role

<h2>About Us</h2> <p>OpenFX is on a mission to move money as freely as data, unrestricted by time zones, banking hours, or legacy systems. We are building the infrastructure that will power the next generation of cross-border payment systems for institutions. The team's execution has been exceptional, and we're scaling at a remarkable pace. Our stellar early team comes with experience in companies like J.P. Morgan, Goldman Sachs, FalconX, Paypal, Affirm, Polygon, Kraken, Nium &amp; others. We're backed by Accel, Lightspeed, NfX and other top-tier investors.</p> <h2>Role Overview</h2> <p>We're hiring a frontend-heavy Full Stack Engineer for our Trading team — the team that owns the client's entire trade experience.</p> <p>Trading owns quote generation, pricing strategy, the spread engine, and the trade lifecycle across GUI, API, and soon conversational AI. Our north star is Total Payment Volume, with Gross Revenue as the control metric.</p> <p>You will own the client-facing surface of that experience. This is where an institutional client sees a live quote, understands the price and fees, commits to a trade, and tracks it through to settlement. You will own architecture for these flows — state management, data fetching, error handling, and performance — and be trusted with the correctness of what the client sees.</p> <p>You will also work across the stack. You'll build and extend the APIs your surfaces depend on, model the data behind them, and ship the backend piece of a feature rather than waiting on someone else to unblock you. You don't need deep backend systems experience for this role, but you do need to be genuinely comfortable there.</p> <p>We're specifically looking for someone with a trading background. Think a crypto exchange, brokerage, or trading platform (CoinDCX, Groww, CoinSwitch Kuber, or similar).</p> <h2>Key Responsibilities</h2> <ul> <li>Own the architecture of critical client trade flows — quote and pricing surfaces, trade initiation, and status and settlement tracking — across GUI, API and conversational AI.</li> <li>Design frontend state and data-fetching patterns, exception handling and retries.</li> <li>Drive frontend performance and reliability — rendering efficiency under frequent updates, load times, and stability on the flows that carry volume.</li> <li>Build and extend the APIs and data models your surfaces depend on, and ship features end-to-end rather than stopping at the boundary.</li> <li>Instrument the client experience — Error rates, flow completion, and latency — problems are visible before clients report them.</li> <li>Partner closely with Design and Product to shape flows, and with backend engineers to shape API contracts.</li> <li>Drive work to closure with Product, Design and Operations. You are accountable for adoption, not just delivery.</li> <li>Act as a product engineer — scope a problem statement, understand its product impact, and take the hard prioritisation calls.</li> <li>Raise the bar through code review and design feedback, and mentor L1/L2 engineers on the team.</li> <li>Build a healthy engineering-excellence and tech-debt backlog — surface the right items, work with the EM on a resolution plan, and drive them to closure.</li> <li>Participate in on-call, respond to incidents with urgency, and turn post-mortems into durable fixes.</li> </ul> <h2>What we are looking for</h2> <p><strong>Must-haves:</strong></p> <ul> <li>5–7 years of experience building production web applications, with the majority of that depth on the frontend.</li> <li><strong>A trading background</strong> — you've worked at a trading company, exchange, or brokerage and have built client-facing systems on a live trade or order path (e.g. CoinDCX, Groww, CoinSwitch Kuber, or similar).</li> <li>Deep expertise in <strong>TypeScript and React</strong>, and strong command of <strong>Redux</strong> or equivalent state management on non-trivial applications.</li> <li>Hands-on experience with <strong>server-side rendering</strong> and <strong>code splitting</strong>, and a clear sense of when each is worth the cost.</li> <li>Strong grasp of frontend architecture — component design, data fetching, error handling, and data synchronisation between client and server.</li> <li>Experience building reliable UIs on top of asynchronous systems, where ordering isn't guaranteed, and failures are partial.</li> <li>Experience writing automated tests for Frontend and working with Frontend test frameworks.</li> <li>Track record on frontend performance — you've diagnosed and fixed a slow production surface.</li> <li>Working backend proficiency: building CRUD and REST APIs, designing schemas and queries on <strong>PostgreSQL</strong>, and comfort in a <strong>Next.js,</strong> <strong>Hono</strong> (or similar) server runtime. You should be able to own the backend of your own feature.</li> <li>Solid command of object-oriented programming principles and low-level design patterns.</li> <li>Comfort with <strong>abstract, ambiguous problems</strong> — you can turn a vague mandate into scoped, sequenced deliverables without waiting for someone to specify it for you.</li> <li><strong>Hands-on and high agency.</strong> You find the important problem and go solve it rather than waiting to be assigned it.</li> <li><strong>Heavy AI user.</strong> You use AI coding tools with real technique and get materially more done because of it.</li> <li><strong>Data-driven</strong>, and a clear written communicator — we are async-heavy and globally distributed.</li> </ul> <p><strong>What helps you stand out:</strong></p> <ul> <li>Experience building real-time financial surfaces — live pricing, order books, or streaming quote updates.</li> <li>Experience with complex financial dashboards, reconciliation views, or transaction history at scale.</li> <li>Experience with FX, multi-currency systems, or cross-border payments.</li> <li>Experience with frontend testing, observability and monitoring tooling.</li> <li>Experienc