Senior Software Engineer (SQL / Web Applications)
Aleja Pokoju 18, Kraków
Ready4S
🏗️ About the role
We’re looking for an experienced engineer with a true engineering mindset — someone who not only writes code, but also understands why certain technical decisions are made. We’re not looking for a “code soldier” who just follows instructions. We want an engineer with opinions — someone who can analyze, reason, and design solutions consciously and thoughtfully.
You’ll be part of a team developing a key component of a real-time data system — a web service that serves as a central part of the application’s architecture. Your work will have a direct impact on the performance, stability, and growth of the product.
💡 Responsibilities
Develop large-scale, high-performance web applications
Contribute to application logic written in Python (not ETL)
Write and optimize complex SQL queries
Design database schemas and participate in architectural decisions
Work with databases as a core part of the system, not just through an ORM
Deploy and maintain applications in production environments
✅ Must have
Expert-level SQL knowledge, including
Experience handling large data volumes (millions/billions of records, high -QPS)
Hands-on experience with schema and database design
Proven track record in building complex web applications or products
Willingness to work with Python
Ability to explain and justify architectural decisions
Proficiency in at least one programming languages at an advanced level
🌱 Nice to have
Query optimization and tuning
Experience writing and managing database migrations
Familiarity with database monitoring and optimization tools
Experience with cloud/data services (AWS, GCP, Azure)
Python doesn’t have to be your main language — what matters is openness and readiness to use it
Why Join This Project?
Work on a high-impact application that is critical to business operations.
Opportunity to shape and modernize the architecture, not just maintain it.
Long-term potential with a multi-year modernization roadmap.
Collaborative international environment with challenging, meaningful problems to solve.
Senior Software Engineer (SQL / Web Applications)
Senior Software Engineer (SQL / Web Applications)
Aleja Pokoju 18, Kraków
Ready4S