Full Stack AI Engineer

Senior Full-Stack Engineer, Agentic AIA growing RegTech SaaS business is hiring a Senior Full-Stack Engineer to help build the next generation of its customer-facing platform from its Cascais engineering hub.The company is developing an AI assistant that will sit inside a highly configurable regulatory platform. Over time, the assistant will help customers create complex workflows through conversation, interpret regulatory changes, work across documents and data, and interact with underlying product capabilities.This hire will have significant influence over how that agent layer is designed, shipped and operated in production.The roleYou will work across the core product and the AI agent layer, taking ownership of features from design through to production.The work will include:Building and operating multi-step AI agent workflowsDesigning tool and function calling between agents and product servicesManaging state, context, retries, fallbacks and human interventionBuilding evaluation and regression approaches for non-deterministic AI behaviourImplementing tracing and observability across agent workflowsManaging latency, token usage and model cost in productionDesigning guardrails around agent behaviour and actionsBuilding full-stack product features across backend and frontend servicesWorking with APIs, databases and cloud infrastructureContributing to architecture and technical design decisionsOwning what you build after release and improving it based on real production behaviourWhat we're looking forYou'll need strong commercial software engineering experience and hands-on experience taking AI agents into production.The strongest profiles will be able to explain a real system they personally helped design and build, including what the agent could do, how it interacted with other systems, what happened when parts of the workflow failed, and how its behaviour was evaluated after release.Experience with some of the following will be useful:C# and .NETPythonReact, Angular or another modern frontend frameworkAzure, AWS or GCPSemantic Kernel, Azure AI Foundry, LangGraph, Pydantic AI or similar agent frameworksRAG and retrieval pipelinesREST APIs and SQL databasesAI evaluation, tracing and observability toolingCI/CD and automated testingExperience across several production AI projects would be particularly relevant.You'll also suit the environment if you're comfortable working in a smaller engineering team where technology is changing quickly, technical decisions are visible and engineers are expected to challenge assumptions, learn quickly and take ownership.What's on offerSalary up to €100,000, depending on experiencePermanent positionHybrid working from Cascais, typically around two days per week in the officePrivate medical insurance25 days' holiday plus public holidaysAccess to AI tooling and professional developmentOpportunity to have significant influence over a new production AI capability as the engineering team growsYou must already have the right to work in Portugal. Visa sponsorship is not available.