Technical practice
How would you design a retrieval-augmented generation system for a business application?
What to coverSuggested preparation: Explain document ingestion, retrieval with a vector database, grounding responses in retrieved material, and handling poor or missing matches. Discuss trade-offs among answer quality, latency, scalability and access to sensitive data.
How would you choose among AI SDKs and orchestration tools for an application?
What to coverSuggested preparation: Compare where an SDK or service such as OpenAI SDK or Bedrock might suffice and where a framework such as LangChain or Google ADK could help. Explain how you would assess complexity, maintainability and integration needs rather than assuming one tool fits every use case.
How would you combine advanced prompting with AI guardrails?
What to coverSuggested preparation: Describe how you would specify the task, constrain outputs and test prompts against ambiguous or unsafe inputs. Explain where application-level validation and controls remain necessary even when prompts are well designed.
How would you evaluate and troubleshoot an applied AI feature?
What to coverSuggested preparation: Describe checks for answer relevance, groundedness, failures, latency and changes after a prompt or retrieval update. The posting lists Langfuse; discuss how tracing could help isolate a problem without assuming Barclays uses a particular evaluation process.
How would you design an AWS data flow to support an AI application?
What to coverSuggested preparation: Use relevant listed services, such as S3, Glue, Athena and Step Functions, to explain ingestion, preparation and orchestration. Address data quality, failure handling and when a different storage or query approach would be preferable.
How would you choose an AWS runtime and deployment approach?
What to coverSuggested preparation: Compare Lambda with ECS or EKS for workload duration, scaling, operational effort and application requirements. Explain how CloudFormation and CloudWatch could support repeatable deployment and operational visibility.
How would you protect sensitive data across an AI application and its data stores?
What to coverSuggested preparation: Discuss least-privilege IAM access, appropriate data controls and secure handling across services such as S3, Lake Formation and RDS or PostgreSQL. Explain how you would review risks at system boundaries rather than treating model guardrails as the only protection.
How would you maintain code quality while delivering applied AI software?
What to coverSuggested preparation: Cover code-review criteria, unit tests for deterministic components, and testing around external AI responses. Explain how you would balance readable, maintainable code with performance and delivery needs.
How would you investigate a slow or unreliable AI-backed application?
What to coverSuggested preparation: Break the request path into retrieval, model calls, application code and infrastructure, then describe what you would measure to locate the issue. Compare improvements against their effects on response quality, cost and operational complexity.
When might you consider a different data platform for an AI workload?
What to coverSuggested preparation: The posting marks Hadoop, Impala, Hive and cloud data technologies such as Snowflake and Databricks as desirable, not mandatory. Compare platforms at a high level using data scale, query patterns, governance and integration needs, without assuming a particular Barclays platform.
Behavioural practice
Tell me about a time you aligned stakeholders on a technical direction.
What to coverSuggested practice question: Give the situation, the competing business and engineering priorities, your actions to explain options to stakeholders, and the result. Include how you handled disagreement or changed the plan in response to feedback.
Describe a time you developed others while maintaining delivery standards.
What to coverSuggested practice question: Use a real mentoring or team-leadership example, stating the situation, your coaching actions and the result. Make clear whether you had people-management responsibility or were guiding specialists through technical leadership.
Tell me about a risk or control concern you identified during delivery.
What to coverSuggested practice question: Explain the situation, how you assessed and communicated the concern, what action you took or escalated, and the result. Focus on your actual decisions and evidence rather than claiming a control was effective without support.
Describe a cross-functional project where requirements changed.
What to coverSuggested practice question: Explain the situation, how you worked with product, design or engineering partners to revise the plan, and the result. Address the trade-off between delivery timing and the quality or maintainability of the solution.
Tell me about a change you led to improve an engineering approach.
What to coverSuggested practice question: Describe the situation, your rationale, how you gained support and executed the change, and the result. Connect the example to strategic priorities or continuous improvement without implying a specific Barclays initiative.