Lead Data Specialist

Position

Lead Data Specialist | Poland | Deloitte Digital

Work arrangement

Full-time

City

Gdansk, Katowice, Krakow, Lodz, Poznan, Rzeszow, Szczecin, Warsaw, Wroclaw

Country

Poland

Department

Consulting

Team

Deloitte Digital

Area of interest

Consulting

Way of work

Remote

Who we are looking for

We're looking for a Lead Data Specialist.

In this role, you'll combine the strengths of a Senior Business Analyst, Technical Writer, Data Architect, and Backend-minded Engineer. You will own key data domains, set standards for data modeling and documentation, and guide other Data Specialists in delivering clean, consistent, developer-ready assets.

Your mission: shape the data architecture, design robust models, define and document APIs, and orchestrate data flows that power products on a global stage. If you love structure, clarity, and craftsmanship — and you can turn complex, fast-changing specs into elegant XML/JSON/YAML and high-quality documentation under time pressure — this role is for you.

Required Skills & Experience:

Data & Modeling

• Strong data literacy: solid grasp of hierarchical data; XML 1.0, JSON, YAML 1.2 (scalars, sequences, mappings, nested structures).
• Proven experience designing and reviewing complex XML/JSON/YAML schemas for large-scale, multi-team systems.
• Foundations in data architecture: conceptual vs. logical modeling; exposure to ERDs and Logical Data Models in real-world projects.

Tools & Wrangling

• Confident in VS Code/Cursor with format/validate extensions; able to define efficient workflows for the squad.
• Capable in Excel or Python for inspection, transforms, and quick analysis of structured data.

Programming & APIs

• Working knowledge of Python or TypeScript (both preferred); comfortable writing Python-like pseudocode to express logic.
• Strong, hands-on experience consuming and documenting APIs in OpenAPI 3.0, including use of Swagger Editor or similar tools.
• Ability to translate mockups and UX flows into well-structured JSON contracts and API payloads.

Collaboration & Communication

• Excellent written and verbal English; able to produce crisp, unambiguous specs for developers and non-technical stakeholders.
• Track record of proactive collaboration with engineers, designers, QA, and SMEs in distributed teams.
• Comfortable facilitating discussions around data requirements, trade-offs, and edge cases.

Mindset

• Entrepreneurial and creative, with strong attention to detail and consistency.
• Intrinsically motivated to grow in data design/modeling/programming and help others do the same.
• Calm under pressure; able to handle time-sensitive changes and evolving requirements without sacrificing quality.

Nice to Have:

• Experience writing technical documentation that developers genuinely appreciate and use.
• Familiarity with schema validation (XSD/JSON Schema), migration/versioning strategies, and backward-compatible API evolution.
• Previous experience in large-scale event, media, or sports-tech ecosystems.

Your future role

Data Ownership & Architecture

• Own and evolve data models and contracts for key business domains.
• Quickly and accurately analyze technical documentation (PDF/Excel), understanding downstream implications for multiple systems and teams.
• Define and enforce standards for XML/JSON/YAML structures, naming conventions, versioning, and documentation quality.
• Drive conceptual and logical data modeling in collaboration with architecture leads.

Design & Documentation

• Explore and analyze XML, JSON, YAML using advanced editors (VS Code/Cursor) with validation, auto-formatting, and schema checks.
• Design clean and consistent XML/JSON/YAML structures to support high-quality technical documentation and reusability.
• Document data flows with conceptual diagrams, mapping tables, and concise pseudo-code (XPath or Python-style).
• Define and maintain REST APIs in OpenAPI 3.0, ensuring alignment between specifications and implementation.

Technical Leadership & Delivery

• Provide hands-on support for backend flows (primarily in TypeScript) and reusable analytical snippets in Python.
• Review and challenge data models, API specifications, and documentation created by other Data Specialists.
• Collaborate with cross-functional teams (Backend, Frontend, UX/UI, QA, Product) to translate business and UX requirements into robust data contracts.
• Own and maintain documentation in Confluence, ensuring clear specs, version history, and links to visual assets.
• Ensure Jira epics, issues, and documentation remain aligned; promote transparency and delivery discipline within the team.

Mentoring & Ways of Working

• Act as a go-to person for data structure, documentation, and API-related questions.
• Mentor junior and mid-level Data Specialists on best practices in data modeling, API design, and technical writing.
• Foster a culture of clarity, speed, and craftsmanship in all areas related to data contracts and documentation.

What we offer

• Working across multiple geographies and clients
• B2B contract
• Access to new technologies
• Personal development training
• Wellbeing initiatives
• Internal career development program

About Deloitte

In Deloitte we support leading global organizations in optimizing and transforming their organizations. This also relates to their finance function. Our consultants offer insights, capabilities, and solutions that change the way these organizations operate and make people-related decisions.

We are currently building in Poland a dedicated team which will focus on advisory in the area of Finance & Performance. The Team will advise our Clients in complex issues relating to i.a. Reporting, Budgeting, Controlling processes. We are looking for high-energy, committed and ambitious people to join our advisory practice. Next to advising on most sophisticated and challenging issues relating to the above mentioned areas, our Consulting professionals will also advise on potential solutions leading to optimisation of the above mentioned processes. This will also include applying the newest technologies.

Are you ready to join our team and help our clients imagine, deliver, and run their future?

About the team

At Deloitte Digital, we connect creativity with technology for business. Bringing empathy, ideas, and experience into digital transformation. We're a creative digital consultancy that fuses strategy, tech and design to identify where businesses need to be, then get them there. Fast. We work with a wide range of iconic local and global organizations, helping them understand and profit from the online and mobile revolution. We approach our work with great energy and passion as we align our client's business aspirations to the goals of the end user.