Senior Fullstack Engineer (f/m/d)

At Upvest, we are on a mission to make investing as easy as spending money. Upvest empowers businesses to offer a wide range of investment products and the best experience in the field of capital market investment and retirement planning. Upvest’s Investment API is easy to integrate so that fintechs and financial institutions can save resources and fully focus on their core business. We are proud to partner with Europe’s leading Fintechs and financial institutions such as DKB, Revolut, N26 and Raisin. Founded in 2017 by Martin Kassing, Upvest now brings together over 270 talented professionals from more than 70 nationalities. Upvest is backed by €280M in total funding from world-class investors, including BlackRock, Tencent, Sapphire Ventures, and Bessemer Venture Partners, Earlybird, Notion Capital, and Motive. Our latest €105M funding round in March 2026 - led by Sapphire and Tencent - serves as a massive catalyst for our growth, allowing us to offer premier investment experience. About the role: Team's mission Upvest's core product is an API: the execution layer that moves securities for our clients. Upfront extends into the layer above it. It's Upvest's operational service panel for enterprise clients, giving their operations, support and compliance staff the ability to handle first-line requests themselves: looking into an end-user's account, checking what happened to an order, answering the question in front of them. Today their options are to ask Upvest support or to build a service panel of their own, which most of them won't do. Our mission is to prove that financial institution customers can replace their fragmented operations with Upfront. That case isn't settled yet, and this team is the one making it. Our users do this work all day, so a clumsy interface is how a task turns back into a ticket for us. Our clients are already asking what AI can do for their operations teams. Agentic operations, exposed over MCP, is where we think this goes. What it should look like in Upfront is still open, and we'd like the person in this role to help define it. Upfront is part of the Clients Tribe at Upvest. Together with the Public API and Tooling Apps teams we enable Upvest’s business to scale efficiently, accelerate our client’s time-to-market and embed intelligence and automation into client processes. Your mission You’ll focus on building what actually creates value for our clients. While our OKRs set the destination, we expect you to help map the route. We prioritize impact and shipping speed over a perfectly groomed backlog. Because you're on a client-facing team, the quality of your output directly impacts client trust – especially since we are handling their customers' money. In our domain, the bar is high: anything touching client funds must be correct and auditable, or it's an incident. We will give you the client context, access, and autonomy to figure out what needs building, rather than just handing you a rigid spec. We also expect you to challenge our internal processes if they are slowing down your efficiency or shipping speed. What you’ll do:Take operational problems from concept to production, working across our React/TypeScript frontend and Go backend services. Own modern interface security. Upfront is where external users act on real end-user data, so you will tackle per-client isolated environments, least-privilege access, and Auth0 integrations in a regulated space. Expand the operational surface across Upvest's internal domains and develop a deep understanding of how our core systems piece together. Help define how software delivery works in an AI-enabled company by pushing AI tooling to its limits to maximize quality and speed while staying compliant. Build agentic operations as we move toward exposing Upfront over MCP. Every action requires a strict audit trail, so you will solve real design problems around what an agent can do autonomously versus what requires human intervention. Work in w