Senior Power BI Developer / BI Technical Lead

act digital; Porto; On-site; EUR 50,000 - 85,000; Full time

Job summary

act digital is seeking a Senior Power BI Developer / BI Technical Lead to design and evolve enterprise-level BI solutions. You will transform complex data into scalable data models, dashboards, and actionable insights using Power BI, SQL, and DAX.

You will own the reporting lifecycle from data extraction to publication, mentor junior developers, and promote governance across the BI ecosystem. You will lead the creation of scalable dashboards, optimize queries, and ensure security and performance

Qualifications

• 8+ years of experience in data analytics or BI development.
• Strong experience with Microsoft BI ecosystem and Power BI.
• Proven ability to build enterprise-level dashboards and data models.
• Experience mentoring developers and guiding technical decisions.

Responsibilities

• Build scalable Power BI solutions and dashboards.
• Develop advanced SQL queries for data extraction and analysis.
• Translate business requirements into DAX calculations and data models.
• Improve report performance and user experience.
• Define and promote Power BI development standards and governance.

Skills

Power BI

SQL

DAX

Mentoring

Governance

Tools

Power BI Desktop

Power BI Service

Power BI Gateways

Job description

We are looking for a highly experienced Senior Power BI Developer / BI Technical Lead to design and evolve enterprise-level Business Intelligence solutions.

In this role, you will transform complex datasets and business requirements into scalable data models, high-performing dashboards, and actionable insights. You will work extensively with Power BI, advanced SQL, and DAX, taking ownership of the complete reporting lifecycle, from data extraction and modelling to visualization, optimization, security, and publication.

As a senior technical reference, you will also review solutions, mentor less experienced developers, and promote consistent engineering and governance standards across the BI ecosystem.

As a Senior Power BI Developer, you will:

• Build scalable and business-focused Power BI solutions.
• Develop advanced SQL queries for complex and historical data extraction.
• Translate sophisticated business rules into effective DAX calculations.
• Improve report performance, refresh times, and user experience.
• Define and promote Power BI development and governance best practices.
• Provide technical guidance to junior and mid-level developers.

Power BI Development

• Design, develop, and maintain enterprise-level dashboards and reports using Power BI.
• Translate business requirements into intuitive and actionable analytical solutions.
• Develop interactive reports that support operational and strategic decision-making.
• Build reusable reporting components and standardized visualization patterns.
• Publish and maintain reports through Power BI Service.
• Ensure dashboards remain accurate, user-friendly, scalable, and aligned with business needs.
• Design efficient and maintainable data models for analytics and reporting.
• Define relationships, hierarchies, dimensions, facts, and calculation structures.
• Apply dimensional modelling and star-schema principles where appropriate.
• Improve model performance, usability, and scalability.
• Ensure consistency between source data, business logic, and report outputs.
• Document data models, dependencies, assumptions, and business rules.

Advanced SQL Development

• Write, debug, and optimize complex SQL queries for data extraction and analysis.
• Work extensively with:
• Complex JOINs
• Common Table Expressions
• Nested subqueries
• UNION and UNION ALL
• Advanced filtering
• Aggregations and GROUP BY logic
• Window and analytical functions
• Extract information from multiple source systems.
• Validate query results against functional and reporting requirements.
• Optimize database interaction and query execution performance.

Historical & Time-Series Data Extraction

• Implement dynamic date parameters and rolling time-period logic.
• Build flexible queries that support evolving reporting periods.
• Handle historical comparisons and time-series analysis.
• Ensure accurate and consistent treatment of dates across data sources and reports.
• Optimize historical data retrieval to reduce unnecessary processing and refresh times.

Dynamic SQL Integration

• Integrate customized SQL queries directly into Power BI.
• Inject dynamic parameters into SQL queries to control data retrieval.
• Push suitable transformations and filters closer to source systems.
• Optimize data loads by reducing unnecessary data volume.
• Balance query folding, source processing, and Power BI transformations appropriately.
• Ensure parameterized data retrieval remains secure, maintainable, and reliable.

Advanced DAX Development

• Create and maintain foundational and complex DAX measures.
• Implement calculations involving:
• Filter context manipulation
• Nested measures
• Conditional business logic
• Dynamic calculations
• Period comparisons
• Troubleshoot incorrect results and context-related calculation issues.
• Optimize DAX expressions for performance and maintainability.
• Establish naming conventions and calculation standards.

Performance Optimization

• Diagnose and resolve report performance issues.
• Optimize:
• DAX measures
• Dataset refreshes
• Visual interactions
• Identify bottlenecks across the full reporting chain.
• Reduce dashboard loading and refresh times.
• Ensure a reliable and responsive experience for end users.
• Recommend sustainable improvements instead of short-term workarounds.

Power BI Service & Administration

• Manage reports, semantic models, workspaces, and access permissions.
• Configure and support Power BI gateways.
• Implement and maintain Row-Level Security.
• Support scheduled refreshes and investigate refresh failures.
• Apply appropriate release, sharing, and workspace management practices.
• Contribute to reliable deployment and lifecycle management across environments.

Technical Leadership & Governance

• Act as the N4-level technical reference for Power BI and BI development.
• Review SQL, DAX, data models, and report implementations.
• Mentor junior and mid-level developers.
• Define and promote development standards and reusable practices.
• Improve consistency across dashboards and reporting solutions.
• Support complex technical decisions and escalations.
• Contribute to BI governance, documentation, quality, and maintainability.

Business Collaboration

• Work closely with business stakeholders to understand analytical and reporting requirements.
• Translate technical data structures into clear and meaningful business insights.
• Explain complex calculations and modelling decisions to non-technical stakeholders.
• Challenge requirements when necessary and propose effective alternatives.
• Ensure delivered solutions support measurable business outcomes.

What We’re Looking For

Mandatory Requirements

• At least 8 years of professional experience in:
• Data Analytics
• A related data-focused area
• Strong experience with the Microsoft BI ecosystem.
• Advanced hands-on expertise in Power BI.
• Proven ability to build enterprise-level dashboards and data models.
• Experience writing and optimizing complex queries independently.
• Strong experience with dynamic historical data extraction.
• Experience injecting parameters into custom SQL queries used by Power BI.
• Deep knowledge of DAX, including advanced calculations and time intelligence.
• Experience troubleshooting reporting, modelling, and refresh performance.
• Strong Power BI Service administration and governance knowledge.
• Previous experience mentoring developers or guiding technical decisions.
• Power BI Desktop
• Power BI Service
• Power BI Gateways
• Workspace Administration
• Semantic Models
• Row-Level Security
• Report Publishing and Refresh Management
• Facts and Dimensions
• Data Relationships

SQL

• Advanced SQL
• Common Table Expressions
• Complex JOINs
• Subqueries
• UNION / UNION ALL
• Aggregation Functions
• Dynamic Date Filtering
• Query Optimization

DAX

• Advanced DAX
• Filter Context
• Nested Measures
• Dynamic Calculations
• Performance Optimization

Technical Leadership

• Code and Solution Reviews
• BI Governance
• Development Standards
• Technical Documentation

Nice to Have

• DA-100, MCSE, or equivalent legacy Microsoft certifications.
• Knowledge of deployment pipelines and controlled BI release processes.
• Experience working with French-speaking stakeholders.
• Professional proficiency in French.

Technical Leadership

• Confidence guiding technical decisions and challenging implementation approaches.
• Ability to mentor developers and share knowledge effectively.
• Strong commitment to quality, consistency, and sustainable solutions.

Analytical Thinking

• Excellent problem-solving and critical-thinking skills.
• Ability to investigate complex data and performance issues.
• Strong attention to detail and data accuracy.

Communication

• Ability to translate complex data structures into clear business insights.
• Strong written and verbal communication skills.
• Comfortable presenting solutions to both technical and non-technical stakeholders.
• High degree of autonomy and accountability.
• Collaborative approach to working with business and technical teams.
• Proactive mindset focused on continuous improvement.