Application Engineer - Home Office in London

At Moss, we give finance professionals the power to automate their day-to-day and make forward-thinking decisions.Our team and culture make us unique — we’re driven by impact and growth, where every one of us strives to learn and excel. Recognised by Sifted’s Rising 100 and LinkedIn's Top Startups, we’re here to help propel your career and together, make Moss a lasting success.We are hiring an Applied AI Engineer to build AI agents and intelligent product capabilities that transform how finance teams work.This is a product engineering role - not an isolated prototyping or research role. You will own agent-based features end to end: from architecture and evaluation through backend integration, deployment, and operation in production.Your ResponsibilitiesBuild and Ship AI AgentsDesign and build agents that automate complex finance workflows.Own features from initial concept and prototype through production deployment.Integrate agents deeply with our backend services, APIs, data model, permissions, and product workflows.Design how agents securely access and use data from across the Moss platform.Turn emerging AI capabilities into reliable, customer-facing product features.Evaluate and Improve Agent PerformanceBuild systematic evaluations for agent quality, reliability, and business impact.Measure and improve accuracy, latency, cost, and user experience.Develop the AI Application ArchitectureApply context-engineering techniques such as RAG, MCP and knowledge graphs.Build appropriate guardrails, approval steps, and human-in-the-loop controls for sensitive financial workflows.Integrate Machine-Learning CapabilitiesCollaborate with data scientists to integrate machine-learning models into our production systems.Build the services, data flows, APIs, and operational tooling required to make models usable within the product.About YouYou are a seasoned software engineer with experience building and operating production applications.You are highly proficient in Python and/or Java and comfortable working across backend services, APIs, data, and application architecture.You have built and shipped at least one agent or LLM-powered product capability end to end.You have personally integrated agents into a broader product and backend architecture - not only developed standalone prototypes.You have practical experience evaluating agents or other non-deterministic AI systems.You understand how to provide agents with the right data and context while respecting security, permissions, and privacy.You communicate clearly and collaborate effectively across engineering, product, and data science.RAG, MCP, knowledge graphs, tool use, memory, and retrieval systemsAI evaluation: offline and online evaluations, test datasets, regression testing, observability, and human reviewLanguage models: Gemini, OpenAI, Anthropic, Llama, Mistral, or similarBackend engineering: Python or Java, REST APIs, Kafka, microservices, and distributed systemsData systems: SQL, PostgreSQL, BigQuery, vector search, and data pipelinesCloud AI platforms: GCP and Vertex AI, or comparable platformsAbout MossMoss is the Finance AI platform for Europe's mid-sized businesses, giving companies real-time visibility and full control over their spend. By automating card issuing, invoice management and expenses, Moss simplifies financial workflows and frees finance and accounting teams from manual, administrative work. Top-of-market compensation package, including equity. 20 days “work from abroad”, 600EUR/GBP Learning & Development Budget, and other local benefits.Unless stated otherwise, benefits apply to full-time positions (interns and working students receive a tailored package).By applying for the above position, you will confirm that you have reviewed and agreed to our Data Privacy Policy.