Backend Engineer

Senior Python Backend Engineer — Legacy System Migration

Location: Spain, Portugal, Italy, United Kingdom
Employment: Full-time | Remote | B2B Contract
Contract Duration: 3–9 months
Seniority: Senior

About the Project

WORKSHORE is looking for an experienced Senior Python Backend Engineer to join a fast-growing European logistics technology company.

The project involves modernizing a mission-critical last-mile delivery platform that processes thousands of parcel events daily.

The existing system is built on Java and Oracle, and the engineering team is gradually migrating its backend architecture to Python and PostgreSQL.

The main challenge is to ensure the stability of a live production system while implementing a modern, scalable technology stack.

We are looking for an engineer with strong technical ownership, excellent problem-solving skills, and proven experience working with complex legacy systems.

Tech Stack

Python, PostgreSQL, Java, Oracle, Docker, REST APIs, Git, GitHub, CI/CD, Google Cloud Platform.

Responsibilities

• Maintain and improve existing backend services while migrating functionality to Python and PostgreSQL.
• Participate in planning and executing an incremental migration of a production system.
• Refactor legacy code and introduce modern engineering practices.
• Develop and optimize PostgreSQL databases, queries, and data models.
• Rebuild critical carrier integrations using the new technology stack.
• Introduce automated unit and integration testing into legacy applications.
• Ensure high availability, performance, and reliability throughout the migration.
• Manage application deployments and production stability.
• Apply AI-assisted development tools to improve engineering productivity.
• Collaborate with Product Managers and engineering teams throughout the development lifecycle.

Requirements

• Extensive commercial experience with Python backend development.
• Advanced PostgreSQL expertise, including query optimization, database design, and complex data processing.
• Proven experience maintaining and modernizing legacy codebases.
• Hands-on experience with technology migrations or major system refactoring.
• Experience developing high-load, high-volume backend applications.
• Strong understanding of unit testing, integration testing, and test automation.
• Experience with Docker, REST APIs, Git, GitHub, and CI/CD pipelines.
• Practical experience using AI-assisted coding tools.
• Ability to independently manage technical tasks and production deployments.
• Strong communication skills and good English.

Nice to Have

• Commercial experience with Java.
• Knowledge of Oracle databases.
• Experience with Google Cloud Platform.
• Familiarity with GitHub Actions or GCP Cloud Build.
• Background in logistics, delivery platforms, or e-commerce.
• Experience working in cross-functional product teams.

What We Offer

• Opportunity to work on a large-scale production platform.
• Challenging backend modernization and migration project.
• High technical ownership and autonomy.
• International engineering team.
• Remote B2B cooperation.
• Opportunity to contribute to long-term architectural improvements.

Interested? Apply through Djinni and share your CV or LinkedIn profile.