Senior Software Engineer (Monolith, AI, React)
Senior Software Engineer (Frontend Focus) – (Monolith, AI, React) – Remote/HybridDaily rate: £500 - £800 (Outside IR35)Duration: 6 - 12 months Start: ASAPMy new client is looking 2 top tier Senior Software Engineers (frontend focused) to join the team on a contract basis. They’re building a next-generation AI platform for engineering simulation and workflows a “super-intelligent AI test lab” that helps engineers turn complex data into actionable insights faster. You will own and evolve our web application and contribute across the platform.About the roleFrontend Ownership: Lead development of the Monolith web app (React + TypeScript), focusing on data-heavy, workflow-centric views like dashboards, charts, experiment timelines, and agent interfaces. Drive component design, design system evolution, and frontend performance improvements.Fullstack Development: Collaborate with backend engineers on Python services (FastAPI/Flask) to design APIs, integrate new capabilities into the frontend, and occasionally implement backend features to unlock better UX.Collaboration & Leadership: Partner with Product, Design, and other engineering teams to scope projects, define success criteria, and solve complex, data-rich workflow challenges. Mentor other engineers on frontend best practices and effective fullstack collaboration.Performance & Observability: Improve frontend and backend performance, implement metrics and logging, and use telemetry to guide UX and product improvements.User Experience Focus: Ensure the platform is fast, intuitive, and reliable for engineers, including accessibility and usability in demanding environments.DeliverablesCompleting and shipping features that were partially developed by their predecessorBuilding and delivering new frontend features aligned with our roadmap over the coming quarters, in collaboration with existing squadsProviding expert guidance on frontend architecture, tooling, and best practices, and contributing to the evolution of our frontend stackIdentifying and resolving urgent frontend security issues in a timely mannerStaying up to date with, and actively leveraging, modern AI-assisted coding practices to improve productivity and code qualityRequirementsExperience: 7+ years in software engineering, building complex, user-facing web applications; experience operating at Senior or Staff level preferred.Frontend Expertise: Advanced React and TypeScript skills; experience structuring large frontends, managing state, routing, and data fetching; strong web fundamentals. Experience building dashboards, visualization-heavy UIs, and experiment or metrics explorers.Backend & Platform Skills: Solid Python experience (FastAPI, Flask, or Django), API design and integration, SQL databases, microservice/cloud architectures, and containerization (Docker/Kubernetes).Collaboration & Quality: Strong testing habits (unit, integration, E2E), CI/CD experience, clear communication, and ability to thrive in high-ambiguity, fast-moving environments.Bonus skillsExperience with ML/AI workflows, experiment tracking, or analytics platforms.Familiarity with GraphQL, typed API clients, SSR/SSG frameworks, and frontend observability tools (Sentry, Datadog, OpenTelemetry).Experience building products for technically skilled or data-savvy users (ML engineers, data scientists, or simulation engineers).