BI developer

What does a BI developer do?

A BI developer builds the reports, dashboards and data models that a business uses to track how it is doing.

The job sits between raw data and the people who make decisions from it.

In Singapore, you find BI developers in banks, insurers, government agencies, retailers, logistics firms and hospitals. They usually sit in a data and analytics team, or in an IT team that supports finance and operations.

A BI developer works with data engineers who load the data and analysts who ask the questions. They also deal with business users in finance, sales and operations, and sometimes with data governance and risk teams.

What the work involves

• Meet business users to find out which numbers they need and how they will use them.
• Write SQL to pull, join and reshape data from the warehouse into tables that are ready for reporting.
• Build and test data models, measures and dashboards in Power BI or Tableau.
• Check report figures against source systems and fix mismatches before users see them.
• Schedule refreshes, watch for failures and tune slow reports.
• Document definitions and answer questions from users about what a number means.

Pay in Singapore

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Skills a BI developer needs

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BI developer job description

We are looking for a BI developer to build and maintain dashboards, data models and reporting pipelines for our business teams.

You will write SQL, model data in a warehouse and publish reports in Power BI or Tableau. You will work with analysts, data engineers and business owners to turn requests into reports that people can trust.

Responsibilities

• Gather reporting requirements from business users and turn them into clear specifications.
• Design dimensional data models, such as star schemas, that suit reporting needs.
• Write and optimise SQL queries and views for reports.
• Build transformation models and tests in dbt or similar tools.
• Develop dashboards and paginated reports in Power BI or Tableau.
• Validate report figures against source systems and reconcile differences.
• Manage refresh schedules, access rules and report performance.
• Set up row-level security so users only see data they are allowed to see.
• Document metric definitions, data sources and report logic.
• Support users, handle change requests and retire reports that nobody uses.

Requirements

• Diploma or degree in information systems, computer science, statistics, business analytics or a related field.
• Typically 2 to 5 years of experience in reporting, analytics or data warehousing for a mid-level role. Fresh graduates are often hired into junior roles.
• Strong SQL, including joins, window functions and query tuning.
• Hands-on experience with Power BI or Tableau. Excel Power Query is often a plus.
• Working knowledge of data modelling and, increasingly, dbt or a similar transformation tool.
• Clear communication with non-technical users, including finance and operations teams.

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BI developer career path

Most BI developers start in reporting or junior developer roles and move up by owning larger models and teams.

The titles below are common in Singapore, though they vary by employer.

1. Junior BI developer

   Entry

   You build reports from existing models, write simpler SQL and fix defects under guidance from a senior colleague.

2. BI developer

   Mid

   You own data models and dashboards from request to release, and work directly with business users.

3. Senior BI developer

   Senior

   You design data models for whole business areas, set reporting standards and review the work of others.

4. BI team lead

   Lead

   You lead a small team, plan the reporting backlog and agree priorities with business heads.

5. Head of business intelligence

   Head

   You set the reporting and analytics direction for the organisation and manage tools, budgets and teams.

The titles are ones commonly used in Singapore; employers may name the levels differently.

Related jobs and their pay

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BI developer interview questions

We wrote these questions from the skills this job needs. They are not an official question bank.

1. What is a star schema, and why would you use it for reporting?

   What a good answer covers

   • Describes a central fact table linked to dimension tables.
   • Explains that it simplifies queries and speeds up aggregation.
   • Gives an example, such as sales facts with date, product and store dimensions.
   • Mentions when a snowflake or flat table may suit better.

2. Explain the grain of a fact table. What goes wrong if you get it wrong?

   What a good answer covers

   • Defines grain as what one row represents.
   • Gives an example, such as one row per order line.
   • Explains that mixed grain causes double counting.
   • Says to decide the grain before adding measures.

3. Write a SQL query to find the top three customers by revenue in each month.

   What a good answer covers

   • Aggregates revenue by customer and month first.
   • Uses a window function such as RANK or ROW_NUMBER with PARTITION BY month.
   • Filters on the rank in an outer query or CTE.
   • Explains how ties are handled.

4. A Power BI report is slow to load. How do you find the cause and fix it?

   What a good answer covers

   • Checks the data model size, relationships and column count.
   • Uses Performance Analyzer to see which visuals are slow.
   • Reduces visuals per page and avoids heavy calculated columns.
   • Considers aggregations, incremental refresh or pushing logic back to SQL.

5. What is the difference between import mode and DirectQuery in Power BI? When do you choose each?

   What a good answer covers

   • Import loads data into the model for fast queries but needs refreshes.
   • DirectQuery sends queries to the source each time and keeps data current.
   • Mentions source load, performance and feature limits.
   • Gives a case for each, such as daily finance reports versus near-live operations views.

6. How do you use dbt in a BI workflow? Give an example of a test you would add.

   What a good answer covers

   • Describes models as SQL select statements built in layers, such as staging and marts.
   • Mentions version control and documentation.
   • Gives tests such as unique, not null or accepted values on a key column.
   • Explains that failed tests stop bad data reaching dashboards.

7. When would you pick Tableau over Power BI, or the other way round?

   What a good answer covers

   • Compares licensing and fit with the existing Microsoft stack.
   • Notes differences in visual flexibility and modelling features.
   • Considers the skills of the team and the users.
   • Recognises that the right tool depends on the case.

8. A finance team sends you monthly Excel files with changing layouts. How would Power Query help?

   What a good answer covers

   • Imports files from a folder and combines them.
   • Cleans headers, types and blank rows in repeatable steps.
   • Handles layout changes with error checks or parameterised steps.
   • Says when to move the process into the warehouse instead.

1. A sales director says your dashboard total does not match the figure in her own report. What do you do?

   What a good answer covers

   • Asks for her report, the filters and the date range she used.
   • Compares definitions, such as booked versus invoiced sales.
   • Traces both figures back to the source tables.
   • Fixes the error or documents the agreed definition, and tells her the outcome.

2. A business user asks for a dashboard with 30 charts on one page. How do you respond?

   What a good answer covers

   • Asks which decisions the dashboard should support.
   • Proposes a short list of key measures with drill-down pages.
   • Shows a quick mock-up to agree the layout.
   • Chooses chart types that match the data and keeps the page uncluttered.

3. Your nightly refresh failed and the CEO's report is blank at 8am. What are your first steps?

   What a good answer covers

   • Checks the refresh logs and the source system status.
   • Reruns the failed step once the cause is clear.
   • Tells the report owner what happened and when it will be fixed.
   • Adds monitoring or alerts and writes up the cause afterwards.

1. Tell us about a time you found an error in a report that had already been shared.

   What a good answer covers

   • Describes how the error was found and its impact.
   • Shows that the developer told users quickly and clearly.
   • Explains the fix and the check added to prevent a repeat.
   • Takes ownership of the mistake.

2. Describe a time you had to explain a technical limit to a non-technical stakeholder.

   What a good answer covers

   • Uses everyday words instead of jargon.
   • Offers an alternative that meets the underlying need.
   • Checks that the stakeholder understood.
   • Gives the result of the conversation.

3. How do you use tools such as ChatGPT in your BI work, and where do you not use them?

   What a good answer covers

   • Gives uses such as drafting SQL, explaining errors or writing documentation.
   • Checks all output against real data before use.
   • Keeps confidential or personal data out of public tools.
   • Follows the employer's policy on AI tools.

1. A dashboard shows customer names and NRIC numbers to all staff. What would you change under the PDPA?

   What a good answer covers

   • Asks whether the data is needed for the report at all.
   • Removes or masks NRIC numbers and other personal data.
   • Applies row-level security and role-based access.
   • Raises the issue with the data protection officer and keeps access logs.

Common questions about a BI developer job

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