Senior Full-Stack Engineer in Barcelona, Catalunya at Zynap

About Zynap

Zynap is redefining how companies defend themselves in cyberspace, building the first AI agent workflow platform for preventive cybersecurity.

Our AI-driven platform acts as the operational brain for security teams, automating what slows them down, connecting what’s fragmented, and transforming threat intelligence into proactive defense. By combining offensive security, threat intelligence, and AI agents, Zynap helps organizations detect faster, respond smarter, and prevent threats before they spread.

Join us in shaping the future of cybersecurity, where anticipation, foresight, and action redefine protection.

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

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