Full Remote · European Timezone · Professional English RequiredAbout the RoleWe're looking for a Senior Software Engineer with an Agentic mindset — someone who doesn't just write code, but builds systems that think, act, and adapt. You'll work on a production AdTech platform with real business impact, and you'll increasingly work alongside AI agents and design agentic workflows as part of your daily engineering practice.This is not a ticket-execution role. We expect you to bring judgment, ask the hard questions, design thoughtfully, and genuinely care about the quality of what you ship — whether that code was written by you, assisted by AI, or executed autonomously by an agent you designed.Responsibilities- Design, develop, and maintain robust, scalable backend services following Domain-Driven Design (DDD) principles.- Take full technical ownership of features — from design through deployment and monitoring.- Build and orchestrate agentic workflows: autonomous pipelines where AI models (Claude, LLMs) take actions, call tools, and solve tasks with minimal human intervention.- Actively participate in architecture decisions with strong analytical thinking and technical depth.- Ensure code quality through SDD, TDD, and BDD methodologies, with sharp attention to detail.- Collaborate on code reviews, refinements, and technical planning.- Proactively identify and address technical debt, performance bottlenecks, and security risks (OWASP, SOLID).- Build and maintain CI/CD pipelines across Bitbucket, GitLab, or GitHub.- Produce well-reasoned technical designs before writing the first line of code.Tech StackLanguages- PHP (required) · JavaScript / Node.Js · Python- Rust (nice to have)Frameworks & Tools- Laravel · Pest · Tailwind CSS- AWS: Lambda, SAM Templates, S3, CloudFront- Terraform · Playwright · Robot Framework · Cypress- Grafana · k6 · PostmanAgentic & AI Tooling- Claude (Anthropic) · Kiro- Experience building or working with LLM-powered agents, tool use,



MCP integrations, or prompt engineering at an engineering levelPlatform & Collaboration- Bitbucket · Jira / Atlassian suiteAdTech (nice to have)- Google Ad Manager (GAM)- Prebid.Js · Prebid ServerMethodologies & Principles- SDD (Spec-Driven Development) · TDD · BDD- SOLID · DDD · OWASP- CI/CD pipelines (Bitbucket Pipelines, GitLab CI, GitHub Actions)What We're Looking For- 5+ years of experience in backend or full-stack software development.- Practical experience with agentic AI systems — building agents, designing tool use, working with LLM APIs, or automating complex workflows with AI.- Strong technical analysis and design skills: you can break down complex problems, propose well-reasoned solutions, and think through the implications of architectural decisions.- Critical thinking: you don't execute blindly. You question, challenge, and improve — including the outputs of AI tools.- Attention to detail: the code you ship is clean, tested, and documented. You apply the same standard to AI-generated code.- True ownership: you're accountable for what you build — in production, over time.- Autonomy: you know how to move forward without hand-holding, and when to raise a flag.- Proactive attitude: you surface improvements, catch problems before they become incidents, and share knowledge freely.- Eagerness to learn: the agentic era is moving fast, and you're moving with it.- Fluent professional English, written and spoken. The team is fully remote and multicultural.What We Offer- Full remote — work from anywhere within the European timezone (CET ±2h).- Small, technical team with minimal overhead.- Direct impact: your decisions ship to production.- A culture of honest feedback and continuous improvement.- Modern tooling — including cutting-edge AI — and freedom to propose new approaches.- A front-row seat to the agentic engineering shift, not just as a user but as a builder.If this sounds like you and you want to build something that matters, we'd love to hear from you.

📌 Sr. Software Engineer (Agentic) (Madrid)
🏢 Refinery89
📍 Madrid