Mid Backend Engineer (Data-focused) (Python / ETL) | €35K - €50K

We're looking for a skilled Mid-Level Data Engineer for one of our clients (TOP Startup) to design, build, and optimize data pipelines and backend services that ensure clean, reliable data across the organization. 🎯 Responsibilities Design, develop, and maintain scalable ETL/ELT pipelines to ingest, transform, and load data from multiple sources. Write clean, efficient Python code with a focus on performance, memory efficiency, and maintainability. Collaborate on database schema design (SQL and NoSQL) and optimize query performance for fast, accurate data access. Implement unit tests, integration tests, and data quality checks to ensure pipeline integrity and prevent issues before production. Deploy and iterate on pipelines using CI/CD practices and containerization tools such as Docker, and participate actively in code reviews. 🛠️ Requirements Strong Python engineering skills (at least 3 years of professional experience) with emphasis on performance and production-quality code. Experience building and operating ETL/ELT data pipelines, pipeline orchestration, and large-scale data ingestion. Familiarity with SQL and NoSQL databases, including schema design and query optimization. Ability to work autonomously, taking high-level requirements from scope definition to production. Capability to quickly understand and contribute to unfamiliar codebases. Experience with CI/CD workflows and containerization (e.g., Docker). Professional proficiency in both English and Spanish. 🤗 We offer Full-time, permanent contract Salary range of €35,000–€50,000 gross per year, based on experience An office with stunning views of Barcelona Flexible working hours and hybrid work options Paid day off on your birthday Weekly fresh fruit, coffee, and tea Friday happy hours (optional) Team-building events Health insurance and flexible compensation Subsidized digital canteen Yearly training budget for continuous growth About Joppy Joppy is a technology recruitment platform built for developers by developers. ✅ No CV is required. Just say what you know and what you want. ✅ Anonymous profile by default. ✅ You choose who can talk to you. Companies cannot write to you until you accept their offer. ✅ Only relevant offers that match your preferences. No more Javascript offers for Java developers. ✅ Get rewarded if you get hired. Keep an eye on tech job opportunities anonymously and find the job that makes you happy.