Software Engineer

💻 Role: Senior Frontend Engineer (React/TS)📍 Location: London / Hybrid 🏦 Industry: FinTech / RegTech💰 Salary: £85k-£90K + Bonus Immersum are currently partnering with a fast-scaling, regulated financial services business looking for a pragmatic, high-caliber Senior Frontend Engineer.If you are an engineer who thrives on owning complex domain logic, building bulletproof architectures, and leveraging modern AI tools to ship fast—this role is for you.Why You’ll Love This BusinessOwnership & Impact: A true "you build it, you run it, you own it" culture with high autonomy and short paths from decision to production.Modern Stack & AI Native: Zero legacy weight—they build with modern React standards and integrate AI tools (Claude Code) daily into their actual workflow.Top-Tier Benefits: Flexible working, annual discretionary bonus, 25 days leave + birthday off, London season ticket loans, and full family/wellbeing support.The Technical ChallengeYou will take point on designing and scaling complex, form-heavy single-page applications responsible for onboarding global corporate clients, funds, and intermediaries.State & Flow Mastery: Engineering complex multi-step flows, handling cross-field dependencies, branching validation, and robust client-side persistence.Architecture Calls: Making, documenting, and defending domain-level architectural calls in front of the tribe.Production Standards: Setting high coverage gates with Vitest/MSW, enforcing WCAG 2.1 AA accessibility, and building with security and observability at the forefront.The StackCore: React 18 (Strict TS), Vite, Azure Static Web AppsState & Navigation: TanStack Query / Form / RouterUI & Styling: Tailwind CSS, Radix UI / shadcn, StorybookTesting: Vitest, React Testing Library, MSWAI Tooling: Claude Code integrated into daily developmentWho Fits Best?Track record of shipping complex, production-grade React/TypeScript SPAs.Deep experience with TanStack Query (cache invalidation, query-key strategy, route prefetching) and complex form logic.Practical experience using AI tools in development (understanding both their power and limitations).Strong technical conviction paired with collaborative, clear communication.📩 Send me a DM or comment below to arrange a confidential conversation!#FrontendEngineering #ReactJS #TypeScript #FinTechJobs #SoftwareEngineering #LondonTech #WebDevelopment #TanStack