About the role
• We are looking for a Senior Full-Stack Engineer to build across the whole platform: from the Go and Python services and event-driven pipelines that power it, to the React application our customers use every day. AI is not a side project here: agents and LLM-powered workflows are core to the product, and AI-driven development is core to how we build it. You will ship features end to end, own them in production, and help raise the bar for how a modern, AI-native engineering team works.

What you'll do
• Build and ship product features end to end: backend services, APIs, and the React front end
• Work across our Go and Python microservices
• Build and evolve our React + TypeScript web application
• Work with event-driven pipelines (queues, workers, schedulers) building scalable solutions
• Build AI-powered product capabilities: agents, LLM integrations, and tooling
• Make AI-driven development a first-class part of how you work, using coding agents and AI tooling daily, and helping shape how the team uses them well
• Own quality end to end: testing, code review, observability, and deployment
• Collaborate closely with Product and Design What we're looking for Must have
• 4+ years building and shipping production software, with senior-level ownership of features from design
• through operation
• Strong hands-on experience with React (with TypeScript) in production applications
• Strong backend experience in Go or Python (at least one is required; we work in both)
• AI-driven development

experience:
genuine fluency with AI coding agents and assistants (e.g. Claude
• Code, Cursor, Codex, etc.) as part of your real development workflow,



and sound judgement about when and how to use them
• Familiarity with AI-driven development practices more broadly: working with LLMs, prompting, and evaluating AI-generated code and output critically
• Solid engineering fundamentals: API design, data modelling, testing, and debugging distributed systems
• Professional English, written and spoken Nice to have
• Experience in both Go and Python
• Familiarity with event-driven architectures: queues, workers, and asynchronous pipelines (SQS and Kafka)
• Experience with AWS and its ecosystem (we also use Terraform, Docker, and Kubernetes)
• Experience building AI-powered product features (tool use, MCP, RAG, evals)
• Background or interest in cybersecurity
• Spanish or additional languages How you work
• Pragmatic and product-minded: you optimise for shipping value to users, not for elegance in the abstract
• Autonomous and proactive: you take a defined problem and drive it to done
• Curious and fast-moving with new tools, especially AI: you experiment, adopt what works, and discard what doesn’t
• Clear, direct communicator who can explain technical trade-offs to technical and non-technical audiences
• High standards without preciousness: you care about quality, and you know when good enough is good enough
• Comfortable operating in a fast-moving start-up environment where no two days look the same What do

we offer
• Scope & impact: Full ownership of features across a modern, AI-native platform, with your work in front of customers from day one
• Flexibility: Flexible hours and a adaptable benefits plan
• Growth & team: In-house training, team-building events, and a young, energised, international team in a start-up environment

📌 Senior Full-Stack Engineer (Barcelona)
🏢 Zynap
📍 Barcelona