The difference between software that works and software that lasts is the depth of its foundations. The Senior Full Stack Engineer (Python/JS) role in Barcelona is about building dependable systems that support growth and decision-making. This is a place for engineers who see the value in robust architecture and trusted data. You decide how technical choices shape the reliability and future of the platform. The person in this role sets the standard for what dependable software means.
Responsibilities
Build and maintain production-grade systems from scratch, including backend services, APIs, data/ML platforms and automation
Design and develop APIs using REST, FastAPI, GraphQL and/or gRPC
Architect cloud-native, serverless, microservices and event-driven systems and ensure cloud integration (GCP and/or AWS)
Implement DevOps practices, including CI/CD, Docker, Kubernetes, Terraform/IaC and automated deployments
Apply security-aware engineering, including IAM least privilege, secrets management, OIDC, Entra ID and permissions management
Lead technical design and mentor engineers, communicating effectively with technical and business stakeholders
Develop frontend/web applications for internal tools, dashboards and proof of concepts
Work with relational and NoSQL databases, such as PostgreSQL, Redis, BigQuery and DynamoDB
Ensure observability and debugging using CloudWatch, Grafana, Datadog or similar tools
Contribute to building AI/ML platforms, agentic AI systems, agents, chatbots, RAG and LLM-based
Requirements
Expertise in software engineering fundamentals and building production-grade systems
Proficiency in Python backend development, including APIs, services, data/ML platforms and automation
Experience with API development (REST, FastAPI, GraphQL and/or gRPC) and architecture skills across cloud-native, serverless, microservices and event-driven systems
Cloud experience (preferably GCP and/or AWS), including ECS, Lambda, SNS, SQS and managed data services
Solid DevOps background: CI/CD, Docker, Kubernetes, Terraform/IaC and automated deployments
Security-aware engineering: IAM least privilege, secrets management, OIDC, Entra ID and permissions management
Experience with AI-assisted programming tools and modern engineering workflows
Ability to lead technical design, mentor engineers and communicate effectively with technical and business stakeholders
Frontend/web app development experience, especially for internal tools, dashboards and proof of concepts
Database experience across relational and NoSQL systems (PostgreSQL, Redis, BigQuery, DynamoDB)
Nice to have
Experience with LangChain, LangGraph, LlamaIndex and prompt engineering
Platform engineering or developer experience background
MLOps experience: model deployment, inferencing, monitoring and production operations
PostgreSQL
Redis
Observability
Grafana
Datadog
IAM
AI
LLM
Senior
Pay
Pay is not stated in the ad.
Estimate take-home pay for a figure you enter
Estimated take-home pay
Explore gross pay after typical payroll taxes for a work location.
Illustrative estimate only; assumes a standard employee profile and may omit benefits, pensions, credits and local rules. Regional and city-specific tax applies only where the selected calculator supports it; other results are country-level. Salary and location are sent only when you calculate: Paysums for supported regions, or WorthOf for wider country coverage. Confirm with an official payroll or tax source before making decisions.
Visa sponsorship and relocation: not stated in the ad.
JobCheckPoint never asks candidates to pay, and genuine employers shouldn't either. If this job asks you for money (registration, training, visa or equipment fees), don't pay. Report it below.
