AI Engineer (Python)

About Quartz Quartz is reimagining wealth management through personalised intelligence. It's the first wealth platform that truly learns from you, understands your goals, and helps you make confident, informed decisions all in one secure platform. Get the experience of a personal banker that works with you 24/7, at a fraction of the cost. About The Role We're looking for an AI Engineer to own Charlie, the personal banker at the heart of Quartz. Charlie is live with UK members today, answering questions about their pensions, ISAs, savings and investments from data we aggregate across their accounts. You'll take responsibility for how Charlie reasons, what it is allowed to say, and how we know it is getting better. This is a production role, not a research one: you'll be judged on answer quality, safety and cost in front of real customers, in a regulated category where a confident wrong answer is worse than no answer. What you'll be doing Own and evolve the Charlie runtime end to end: agent roles and handoffs, prompt and tool architecture, model routing across providers, conversation memory, and the MCP integrations that give Charlie typed access to data in our Kotlin backendDesign and maintain the guardrails that keep Charlie accurate, compliant and on-brand, including what it must not do in a business that is not yet authorised to give regulated financial adviceBuild and run our evaluation pipeline: define quality and relevance metrics, curate eval sets from real conversations, and gate releases on them so regressions never reach membersDrive reliability and cost: instrument every conversation, hunt down failure modes such as loops, duplicated actions and tool misuse, and keep inference spend proportional to the value deliveredEvaluate and integrate external capabilities (web search, market data, model providers) and make clear build-versus-buy recommendationsWork with product and the wider engineering team to turn wealth guidance logic into behaviour Charlie can execute safely, and feed what you learn from conversations back into the roadmapSet the standards for how we build with LLMs at Quartz: testing, observability, prompt versioning and release discipline What you'll need 5+ years of software engineering experience, including meaningful ownership of a customer-facing LLM system in productionStrong Python and FastAPI and strong relational data modelling in Postgres with SQLHands-on experience with agentic or tool-calling systems: function calling, retrieval, structured outputs, multi-step workflowsPractical experience with evaluation of non-deterministic systems: you have built eval sets, chosen metrics and defended a release decision with themSolid grasp of guardrails and safety patterns for LLM applications, and the judgement to know when a model should declineStartup or scale-up experience; you are comfortable owning a system alone and making it robustQuick to learn, ambitious and driven by resultsFluency in English Nice to have Experience in financial services, wealth management or another regulated consumer domain, and an understanding of what an AI assistant can and cannot say thereExperience with workflow orchestration for long-running agent tasks (Temporal or similar)Familiarity with search and retrieval APIs (for example Exa) and vector or hybrid retrieval over structured financial dataCost engineering for LLM systems: caching, model routing, prompt compressionExposure to a product-focused environment where you talk to users and read their conversationsSome Kotlin or JVM experience, or willingness to pick it up