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

Open 23d

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. We work with leading technologies including AWS, Azure, GCP, Databricks, and Snowflake, and combine strong engineering culture with a consulting mindset and a continuous focus on growth and knowledge sharing.

Our client is a software company running a large, business-critical ERP system used to support core operational processes such as payroll, billing and workforce scheduling. The organisation is in the middle of a multi-year modernisation programme, moving away from a legacy technology stack toward a modern .NET/web-based platform, while keeping the legacy system fully operational in production throughout the transition.

Contract: B2B or Freelance

You will be:

Strong, hands-on SQL Server expertise (design, indexing, query optimisation, operational practices).
Solid working knowledge of PostgreSQL, sufficient to assess migration feasibility and compatibility.
Proven experience optimising query and index performance in production environments.
Experience modernising 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.

Your profile:

  • 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, prioritised, business-readable recommendations for non-DBA stakeholders.
  • Work from the European Union region and a work permit are required.

Tasks

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 prioritise 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.

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.

Recruitment Process:

CV review – HR call – InterviewClient Interview – Decision

What this application asks

greenhouse

First Name, Last Name, Email, Phone, Resume/CV, Cover Letter

  • LinkedIn Profile optional
  • Website optional
  • Where did you find this job offer? choose one
  • What is your notice period?
  • What is your preferred form of cooperation?
  • What are your financial expectations?
  • Please specify if the salary expectation are provided hourly or monthly
  • Please specify if the given salary is in net or gross value
  • Currency of the salary expectations
  • What country do you currently reside in? choose one
  • Do you have documents entitling you to work in the European Union (valid work permits to work in the EU)? choose one
  • Do you speak English at a minimum B2 level? choose one
  • I declare that I agree to the processing of my Personal Data contained in the content of documents sent in response to the job/cooperation offer, and Personal Data collected during a possible recruitment interview, in order to participate in future recruitment processes conducted by the Administrator, i.e. Xebia sp. z o.o. with its registered office in Wrocław. choose one
  • I declare that I agree to sending to my e-mail address indicated in the content of recruitment documents, any information about recruitment processes conducted by the Administrator, i.e. Xebia sp. z o.o. with its registered office in Wrocław. choose one
  • The administrator of Personal Data is Xebia sp. z o.o. with its registered office in Wrocław, ul. Sucha 3, 50-086 Wrocław, KRS: 0000978067, NIP: 8971719181, REGON: 020363023 with a share capital of PLN 37 168 600.00. Your data contained in the CV will be processed only for recruitment purposes. The legal basis for the processing of your personal data is art. 221 cl. 1 of the Labour Code. If you provide separate consent, we will process your personal data also for future recruitment purposes. You have the right to access your personal data, to correct them, to remove them, to restrict their processing, to transfer your data, to submit an objection, to withdraw consent to data processing any time without affecting the lawfulness of processing carried out on the basis of the consent before it was withdrawn. In order to exercise the abovementioned rights, please send an e-mail with your request to: [email protected]. If you believe that your data are processed illegally, you can submit a complaint to the supervisory body with its registered office in ul. Stawki 2, Warsaw. We may only disclose your personal data if you provide consent thereto or to authorised bodies, when necessary. choose one

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