Senior Database Architect (SQL Server & PostgreSQL) - B2B / Freelancers

About the Position

Xebia is a global AI-first, digital transformation, and engineering partner. With over 25 years of experience and a team of 5,000 professionals across 16 countries, we help organizations design and build scalable products, platforms, and data-driven solutions. We are currently seeking a Senior Database Architect (SQL Server & PostgreSQL) for a B2B or freelance role in Bulgaria or Poland.

Responsibilities

• Review the current SQL Server database design, indexes, queries, and operational practices.
• Identify performance issues, technical debt, risks, and areas that are already working well.
• Recommend and prioritize pragmatic improvements.
• Assess the feasibility of migrating from SQL Server to PostgreSQL, identifying compatibility issues, risks, expected effort, and possible migration approaches.
• Define and implement robust database observability and performance monitoring, including performance baselines, query-level diagnostics, wait statistics, blocking/deadlock detection, capacity trends, and actionable alerting.
• Work within an AI-native engineering environment, using Specification-Driven Development (SDD) frameworks such as OpenSpec to structure requirements, implementation plans, validation, and traceability.

Requirements

• Strong, hands-on SQL Server expertise (design, indexing, query optimization, operational practices).
• Solid working knowledge of PostgreSQL, sufficient to assess migration feasibility and compatibility.
• Proven experience optimizing query and index performance in production environments.
• Experience modernizing or refactoring databases behind legacy applications.
• Ability to define and set up database observability/monitoring (baselines, diagnostics, wait stats, deadlock detection, alerting).
• A pragmatic, risk-aware approach that balances improvement effort against migration cost and business risk.
• Experience assessing and scoping SQL Server → PostgreSQL migrations (not necessarily having executed a full migration).
• Experience working in environments where legacy and modern systems coexist in production during a transition.
• Comfort working with Specification-Driven Development (SDD) frameworks such as OpenSpec, or similar structured requirements/traceability approaches.
• Ability to produce clear, prioritized, business-readable recommendations for non-DBA stakeholders.
• Work from the European Union region and a work permit are required.

Nice to Have

• Prior exposure to legacy 4GL or transpiled/generated codebases.
• Familiarity with .NET/Blazor application ecosystems as a consumer of the data layer.
• Experience with database-heavy ERP systems (payroll, billing, scheduling domains).
• Experience in AI-assisted/AI-native engineering workflows more broadly.

We Offer

• Opportunity to work with a global leader in digital transformation and engineering.
• Collaborate with a diverse team of experts in AI, Data, Cloud, and Intelligent Automation.
• Work with leading technologies including AWS, Azure, GCP, Databricks, and Snowflake.
• Continuous focus on growth and knowledge sharing.
• Be part of a people-first culture with a strong focus on engineering excellence.

About the Company

Xebia is a global AI-first, digital transformation, and engineering partner. With over 25 years of experience and a team of 5,000 professionals across 16 countries, we help organizations design and build scalable products, platforms, and data-driven solutions. We specialize in Artificial Intelligence, Data and Cloud, Intelligent Automation, and Digital Products, combining deep technical expertise with a strong focus on engineering excellence and a people-first culture.

In the CEE region, we’re a team of nearly 1,000 experts delivering modern applications, data platforms, and AI solutions for clients such as McLaren, Aviva, Deloitte, Spotify, Disney, ING, UPS, Tesco, Truecaller, AllSaints, Volotea, Schmitz Cargobull, Allegro, InPost, and many, many more.