Prepare for and practice interview questions from National Australia Bank.

National Australia Bank Interview Questions

A/B Testing

Algorithms

Analytics

Machine Learning

Probability

Product Metrics

Python

Statistics

National Australia Bank Interview Guides

Suppose there exists a new airline named Jetco that flies domestically across North America. Jetco recently had a study commissioned that tested the boarding time of every airline, and it came out that Jetco had the fastest average boarding times of any airline.

What factors could have biased this result, and what would you look into?

What could potentially bias the average boarding time in favor of an airline that only flies domestically?

What could potentially bias the average boarding time in favor of an airline that only flies domestically?

Boarding Times Bias

A new airline came out as the fastest average boarding times compared to other airlines.  What factors could have biased this result and what would you look into?

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

What is a key disadvantage of the F-test when compared to multiple t-tests?

What is a key disadvantage of the F-test when compared to multiple t-tests?

Hundreds of Hypotheses

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

In an A/B test, how can you check if assignment to the various buckets was truly random?

In an A/B test, which of the following is a common method to determine if the assignment to the test groups was truly random?

In an A/B test, which of the following is a common method to determine if the assignment to the test groups was truly random?

Random Bucketing

A/B Testing & Experimentation

National Australia Bank Salaries by Position

Role - JAVA ENGINEERExperience- 4-13 years Purpose<ul><li>The Consultant, Java Engineer role exists to ensure the delivery of the Right data to the Right customer at the Right time and at the Right Cost using the Right tools and the Right Technology on NAB’s target state (cloud) data platform Ada.</li><li>Enable the move, flow and processing of reusable data assets in the Technology and Enterprise Operations space for both Analytics and Insights.</li><li>Design, build, and develop target-state with approved framework.</li><li>Enhance business user experience on the target state platforms through robust, performant and resilient Java backend services and api.</li><li>Support the team and the enterprise stakeholders in driving informed business decisions by delivering a cloud-based end to end data-centric and engineering solutions on our target state platforms.</li><li>Collaborate with SMEs, Business to ensure end to end data delivery and the right outcome is delivered to the business.</li></ul> Essential capabilities<ul><li>In-depth understanding of data engineering practices and big data technologies.</li><li>Attention to detail, and experience in quality assurance (e.g. peer-review) and best practices for testing.</li><li>Ability to drive innovative and efficient solutions to stakeholders’ big data engineering needs.</li><li>Strong written and verbal communication skills.</li><li>Critical thinking and curiosity to understand problems and determine solutions.</li><li>Expertise in Java, Microservices, PostgreSQL, AWS, and API development. Strong understanding of data engineering practices, Big Data technologies, and dimensional data modelling.</li><li>Proficient in SQL scripting. Familiarity with AWS services and source control tools</li><li>Strong data analytical skills with data exploratory skills and the ability to investigate and determine root cause</li><li>Go-getter with the ability to lead initiative with minimum supervision</li></ul> Experience<ul><li>Bachelor’s degree in computer science, Analytics, Engineering, or related field. Hands-on experience with Java microservice development. Performance improvement, api creation and integration.</li><li>Continuous improvement and performance optimisation practice ensuring high levels of performance, availability and integrity.</li><li>Proven consulting and mentoring experience.</li><li>Experience in working within an Agile environment.</li><li>Experience in applying DevOps practices, SDLC, CI/CD principles to build automated pipelines and deployment.</li></ul> Key Accountabilities<ul><li>Build strategic and reusable enterprise data assets</li><li>Effective prioritisation and completion of assigned activities</li><li>Identify and timely escalation of any issues as required</li><li>Develop stakeholder relationships across supporting business unit and the wider NAB enterprise</li></ul> Key Performance IndicatorsProactively manage risk, meeting all policy and compliance requirements; perform controls; adhere to process and procedures pertinent to role; and escalate events, issues or breaches as they are identified (risk accountability forms part of all roles, as everyone is responsible for managing risk and compliance).# Reusable data assets in production# Resilient and performant data pipelines

Experience - 4+ years Essential capabilities<ul><li>Strong analytical capability, with close attention to detail and pro-active approach to problem-solving</li><li>Ability to write and enhance ETL using SQL, Python, etc.</li><li>Team player and proven ability to collaborate and achieve effective outcomes</li><li>Proven Power BI experience</li></ul>Other capabilities<ul><li>Ability to build rapport with team and business stakeholders.</li></ul>Understanding of the Enterprise Property & Strategic Sourcing DomainExperience<ul><li>Experience as a data analyst in complex business settings.</li><li>Proven ability to analyse data and present it in an effective and meaningful manner</li><li>Clear experience of Agile behaviours, principles, tools and techniques.</li></ul>Technical skills - Minimum requirements:<ul><li>Python, SQL</li><li>GitHub</li><li>Data visualisation and story telling usingPowerBI</li></ul>Understanding of technology infrastructure

Business Analyst RoleThis is a senior business analysis role within the Liquidity Management team, focusing on cash concentration, liquidity forecasting, intraday liquidity monitoring, and regulatory reporting. The role involves working closely with business stakeholders, product owners, and technology teams to define, document, and deliver functional and strategic enhancements across the liquidity management and treasury ecosystem. The incumbent will be exposed to banking products, liquidity management systems (LMS), cash flow analytics, funding optimization, financial messaging standards, and in particular solutions such as Intellect. The Business Analyst – Liquidity Management will act as a bridge between business and technology teams, ensuring that system design and functional delivery align with business objectives, regulatory standards, and operational excellence. Key Responsibilities • Act as SME for liquidity-related processes such as:<ol><li>Cash pooling, cash concentration, sweeping, notional pooling</li><li>Intraday liquidity reporting and monitoring</li><li>Regulatory liquidity ratios (LCR, NSFR, ALMM)</li></ol> • Translate business needs into functional specifications, user stories, and acceptance criteria for development and testing teams.<ul><li>Engage with business stakeholders, Treasury, Finance, Risk, and Operations teams to gather, analyze, and document business requirements.</li><li> • Support the end-to-end lifecycle of liquidity management initiatives — from ideation, requirement definition, design, testing, implementation, and post-go-live support.</li><li> • Conduct detailed analysis on liquidity flows, balances, intraday movements, and forecast accuracy, and identify automation or process improvement opportunities.</li><li> • Define and validate data mapping, transformation logic, and integration points between LMS, core banking, and treasury systems.</li><li> • Support UAT planning, test case definition, and validation of system changes.</li><li> • Collaborate with developers and solution architects to ensure technical feasibility and alignment with enterprise architecture standards.</li><li> • Support production changes, releases, and BAU operations, ensuring compliance with Change and Incident Management processes.</li><li> • Provide functional and process training to users and operations teams as needed.</li><li> </li></ul>What You Will Bring• Proven experience working with liquidity management platforms such as Intellect LMS, Finastra Liquidity Manager, or equivalent treasury systems.• Total Experience: 11+ years overall with at least 5 years in business analysis within liquidity management, treasury, or trade working capital domains. • Strong understanding of banking liquidity processes, including: • Cash and liquidity forecasting • Nostro/Vostro reconciliation and cash position analysis • Intraday liquidity monitoring and optimization • Regulatory liquidity reporting (LCR, NSFR) • Ability to perform data analysis, SQL queries, and validation across multi-system environments. • Experience of working in Agile and DevOps environments with tools like Rally/JIRA, Confluence, and ServiceNow. • High level understanding with microservices, APIs, and cloud-based solutions (AWS/Azure) from a business perspective. • Excellent documentation, analytical, and communication skills with ability to translate business goals into clear, actionable requirements. • A self-starter with strong ownership, problem-solving attitude, and ability to work under pressure. Tools and Technologies (Good to have)• ServiceNow – for incident, change, and problem management tracking. • Rally/JIRA / Confluence – for Agile delivery and documentation. • SQL / Excel/VBA / Power BI / Tableau – for data validation and liquidity analytics.

Experience- 5-16 years Purpose: The role will be involved in Designing, development/enhancing a range of technology applications/services through our change management set up. Activities may involve design, development, test and implement the Acquiring application software. The Acquiring portfolio of applications underpins the following services provided by NAB - ATMs, EFTPOS, Ecommerce Gateways and interfacing into multiple downstream applications for Authorisation, reporting, Fraud, Settlement and reconciliation. Core Responsibilities: · Design, Estimate, code and test enhancement/development projects for assigned application/s (Acquiring applications - Base24 EPS and UPF. Which will be implemented on Cloud Technology – Azure and AWS. · Should have worked on Groovy, C++ and Linux platform. · Create support documentation and provide advice regarding applications to enable support function to work pro-actively. · Contribute to the design/development of changes to technology applications to ensure quality, supportable change is delivered into Production. · Contribute to the review and redesign of processes or procedures, on an ongoing basis, to deliver improved team productivity or efficiency. Success: • Successful implementation of projects and business realising the full benefits of the projects. • Development of tools and processes for the smooth run of the Delivery platform. Success is measured as follows:• Quality of Design and Development. • Quality and timeliness of the software delivery. • Improvements to the tools and work environment. • Documentation of key processes and implementation of team operating procedures Critical Experiences: • 5 to 16+ years working in Switching technology environment in a Tier 1 Bank. • 5+ years of analysis and design experience on complex projects. • Demonstrated experience in Design and delivering quality change to a switching system using CI/CD pipeline. • Experience in cloud migration projects. Core Skills & Capabilities required: • 5 to 13+ years of relevant software development experience in a Tier 1 Bank • Minimum 3 years of exp in Base 24 EPS and/or UPF • Experience with cloud technologies - AWS, Azure. • Solid work experience in Java, Groovy, C++. • Experience in Devops using Jenkins and other CI/CD tools. • Testing experience using transaction simulators like FinSim/Paysim. • Understanding of software development lifecycle, including development, testing, implementation and production support. • Understanding of Acquiring business.

Experience – 4 to 14 years Skills -• Proficient in executing ETL processes between data environments• Proficient at coding in SQL (additional knowledge in Python and R is highly regarded)• Proficient at creating analytics related documentation• Communication skills (written and verbal)• Stakeholder engagement skills• Commercial problem-solving capability• Experience using cloud based environments (such as AWS S3/Redshift or Google GO) is highly regarded. Knowledge -• Strong knowledge of data wrangling/engineering principles, tools and techniques• Knowledge on how to bring together disparate data in an efficient manner to create meaningful data flat files• Awareness of data security principles• Basic proficiency in modelling techniques (preferred, not required)• AWS cloud analytics platform knowledge (preferred, not required)• NAB data environment (preferred, not required)• Tertiary qualification in Information Technology or Computer Science (preferred, not required) Abilities- • Passion for upskilling, providing feedback and mentoring peers• Understanding ambiguous/complex datasets and business rules to bring them together to create insights• Working with others in a collaborative manner to achieve a common objective• Have a willingness to engage others and share knowledge• Attention to detail particularly with data integrity and applying correct formats to data elements• Be able to communicate technical concepts details in simple language to senior stakeholders• Enjoy the challenge that a dynamic, fast paced and complex organisation brings

The Opportunity This is a role for a visionary technical leader who operates as a strategic force multiplier for the entire engineering organization. As a Principal Platform Engineer (SDE4) at NAB, you will be responsible for setting the long-term technical vision for critical domains of our engineering platform. You will tackle our most complex and ambiguous challenges, pioneering innovative solutions that advance the state-of-the-art for financial technology at scale. Your influence will extend far beyond the Platform Engineering & Developer Experience teams; you will collaborate with senior technology leaders, establish engineering standards, and mentor other senior engineers, shaping the technical fabric of the bank. If you are driven by the challenge of solving large-scale distributed systems problems and have a passion for creating an environment where hundreds of engineers can thrive, this is your platform to make a lasting impact. What You'll Do As a SDE4, your focus will be on strategy, architecture, and technical leadership, driving the long-term success and scalability of the NAB Engineering Foundation.<ul><li>Define Technical Vision and Strategy: Define and own the long-term technical vision, architecture, and roadmap for critical platform domains, such as our enterprise container platform, multi-cloud infrastructure strategy, or core developer experience. Your work will set the direction for years to come.</li><li>Architect for the Future: Lead the architectural design of complex, cross-functional platform solutions. You will ensure these systems are secure, compliant, highly scalable, and cost-effective, anticipating future business needs and technological shifts.</li><li>Solve Ambiguous, Large-Scale Problems: Tackle the most technically challenging and ill-defined problems within the platform space. This involves deep-dive analysis, prototyping, and creating novel solutions that push the boundaries of what's possible.</li><li>Champion Engineering Excellence: Act as a steward for engineering quality across the orgs. You will establish and evangelize best practices, author design documents and RFCs, and lead by example to cultivate a culture of high-performance engineering.</li><li>Mentor and Elevate Senior Talent: Serve as a mentor and technical guide to other senior engineers (SDE3s) and team leads. You will be a "force multiplier," elevating the technical capabilities of the entire organization through your guidance and expertise.</li><li>Collaborate with Senior Leadership: Partner with senior technology leaders (Heads of Engineering) to align the platform strategy with NAB's overarching business and technology objectives, ensuring your work delivers maximum strategic value.</li></ul> What You'll Bring We are seeking a world-class engineer with a history of strategic impact and a reputation for technical excellence and thought leadership.<ul><li>Experience: 9+ years of experience in software and platform engineering, with significant time spent in a technical leadership, staff, or principal engineer capacity.</li><li>Distributed Systems Mastery: Deep, recognized expertise in designing, building, and operating large-scale, fault-tolerant distributed systems on multi-cloud platforms (AWS and Google Cloud / Azure).</li><li>Cloud-Native Authority: Mastery of Kubernetes and the cloud-native ecosystem. You have architected and operated Kubernetes platforms at enterprise scale, likely in complex, multi-tenant environments, and have a profound understanding of its internals.</li><li>Strategic Influence: Proven ability to drive large-scale, cross-team technical initiatives from conception through to production. You are adept at building consensus and influencing technical direction without direct authority.</li><li>Exceptional Communication: World-class communication and interpersonal skills. You can crisply articulate highly complex technical concepts to diverse audiences, from junior engineers to executive leadership.</li><li>Visionary Mindset: A strategic thinker who can look beyond immediate problems to anticipate future challenges and opportunities, translating them into a coherent technical strategy.</li><li>AI Innovation: Lead organizational AI platform strategy and GenAI technology adoption. Design intelligent platforms with autonomous capabilities and predictive operations, like developer agents, code review agents, test agents, SRE agents etc.</li><li>Multi-Cloud architecture & Strategy: You have experience in designing and architecting, multi-cloud / cross-cloud-platform systems, and defining clear strategies for maintaining multi-cloud infrastructure at scale. </li><li>Risk & Security: As part of being a banking / financial institution, security and risk in ingrained in our daily activity. A key competency would be not just building great tech but also building with the best practices of security & risk ingrained in our decisions and strategies.</li></ul> Good to Have These qualifications indicate a candidate operating at the forefront of the industry:<ul><li>Demonstrable experience in defining and implementing AI-driven platform capabilities.</li><li>Active contributions to open-source projects within the cloud-native, infrastructure, or observability space.</li><li>Deep expertise with advanced deployment strategies (e.g., canary, blue-green) and modern continuous delivery platforms like Harness, especially in the context of highly regulated financial workloads.</li><li>Published work, such as conference talks, blog posts, or whitepapers, on topics related to platform engineering, distributed systems, or cloud architecture.</li></ul>

Question	Topic	Difficulty	Ask Chance
Boarding Times Bias	Statistics	Medium	Very High
Hundreds of Hypotheses	Statistics	Medium	Very High
Random Bucketing	A/B Testing & Experimentation	Medium	Very High

National Australia Bank Interview Questions

National Australia Bank Interview Guides

National Australia Bank Interview Questions

National Australia Bank Salaries by Position

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