CCDV-FClaude Certified Developer - Foundations
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| # | Question | Time | |
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| 1 | A teammate has submitted a pull request that adds a Claude-powered feature to your service. The code works, but the prompt and model selection are hard-coded inline, error handling is missing, and there are no tests for the integration. What would you request during code review? | – | |
| 2 | Your Claude application’s prompt was written months ago and has not been updated. The team has discovered through evals that the prompt produces good results on common cases but underperforms on a specific category of inputs that has grown in volume. How would you respond? | – | |
| 3 | Your Claude application's error handling currently logs every API error with the same severity level. The team wants to differentiate between errors that should page an on-call engineer and errors that should be logged for later review. How would you structure the error handling? | – | |
| 4 | A teammate has asked why your Claude application sometimes produces a response that includes the prompt text repeated back, and other times produces a response with the prompt text rephrased. They suspect a bug in the application’s request construction. How would you respond? | – | |
| 5 | You are building an agent that needs to call several internal APIs and a database in a structured, repeatable way. Your team has decided to use the Claude Agent SDK rather than build a custom loop. You are setting up the agent’s tool definitions and execution loop. How would you set up the tools and execution loop? | – | |
| 6 | You are running Claude Code as part of an automated continuous integration pipeline. The pipeline needs Claude Code to execute a set of well-defined tasks without prompting for confirmation, and the output needs to be captured for downstream processing. How would you configure the pipeline? | – | |
| 7 | Your agent makes 10 to 15 tool calls per task, and you have noticed it sometimes loses track of earlier results by the time it reaches later steps. The agent's context window is large enough to hold all the messages, but the relevant information appears to get buried as the conversation grows. How would you address this? | – | |
| 8 | You are establishing the guardrail strategy for a Claude application. The team wants to ensure guardrail failure does not expose the application to unsafe behavior. The guardrail strategy would... | – | |
| 9 | A teammate has asked you to explain why your Claude agent’s tools include detailed descriptions in the tool definition, even when the tool name is already descriptive. The teammate suggests removing the descriptions to simplify the tool definitions. How would you respond? | – | |
| 10 | A teammate has asked you to explain the difference between context engineering and prompt engineering. They have heard the terms used interchangeably and are unsure how each applies to a Claude application that processes long-running multi-step tasks. How would you describe the distinction? | – | |
| 11 | Your team is integrating Claude into an existing REST API service. The service handles concurrent requests, and you are deciding how to structure the Claude API calls within the existing async codebase. How would you structure the Claude calls? | – | |
| 12 | Your Claude application uses structured output that is consumed by downstream code. The team wants to handle malformed or unexpected output gracefully so it does not crash downstream systems. The best choice for handling this issue would be to ... | – | |
| 13 | Your Claude application is hitting context window limits when processing long customer service transcripts. A junior developer suggests increasing the temperature parameter to fix the issue. How would you respond? | – | |
| 14 | Your Claude application requests structured JSON output from the model. Most of the time the JSON is well-formed, but occasionally Claude returns malformed JSON that breaks downstream processing. How would you handle the malformed output? | – | |
| 15 | Your team is debating how to manage the prompts used in your Claude application. Some prompts are checked into the code repository, some live in a separate configuration file, and some are constructed inline at runtime. The result is inconsistent, and a recent prompt change went out without code review. What steps would you take? | – | |
| 16 | Your team is preparing to roll out a configuration change that updates several prompt versions across a Claude application used by multiple downstream systems. The change has already been tested in staging, but the team has not assessed how the prompt change will affect each downstream system that depends on the application’s output. What would you do before rolling out the change? | – | |
| 17 | A teammate is debugging a Claude application whose system prompt has grown to several hundred lines and now contains overlapping, contradictory, and obsolete instructions. How would you advise the teammate? | – | |
| 18 | A new Claude model release includes performance improvements for several reasoning tasks but has changed the format of its responses to system prompts that use multi-section instructions. Your application uses multi-section system prompts heavily. Initial evaluation on the application’s actual workload shows the new model performs 8 percent better on reasoning tasks but produces malformed output on roughly 3 percent of requests because of the format change. The team is debating whether to upgrade. How would you decide? | – | |
| 19 | Your Claude application has multi-step workflows where each step’s output is needed only briefly before the agent moves on. The cumulative tool output is filling the context window with content that is no longer relevant. How would you handle the accumulating tool output? | – | |
| 20 | You have just shipped a new Claude-powered application to production. The development phase is complete, and the system is now in active use by internal teams. The next phase of work for this system is ... | – | |
| 21 | Your application uses the Messages API to handle multi-turn conversations. Each new turn resends the entire conversation history, and your token costs are growing as conversations get longer. You suspect there is a more efficient approach. How would you address this? | – | |
| 22 | Your Claude application produces good responses for typical inputs but struggles with edge cases. You have several labeled examples of edge-case inputs and the desired response for each. You want to use these examples to improve the model's handling of edge cases. What is the best way to use these examples? | – | |
| 23 | You are writing a system prompt for a Claude application that needs to produce output in a specific JSON shape. The downstream system will reject any output that does not match the schema. Your prompt would need to ... | – | |
| 24 | You are deciding between Claude models for a task. The team has identified three relevant tradeoff dimensions: quality, latency, and cost. The right model is the one that ... | – | |
| 25 | A teammate is reviewing the team’s threat model for a Claude application and has asked you to identify the categories of AI-specific threats that the model should cover. The teammate has already listed traditional web application threats and wants to know what additional categories apply to a Claude application. Which AI-specific threat categories would you add? | – | |
| 26 | You are building a Claude application that needs to maintain a persistent connection to a service that streams real-time updates. The team is unsure what communication pattern to use. Which communication pattern would you use? | – | |
| 27 | Your Claude application runs long agentic workflows where the agent makes many tool calls, and the conversation history grows quickly. After about 20 tool calls, you notice the agent's responses become less focused and sometimes ignore earlier task constraints. How would you address this? | – | |
| 28 | You are extending a Claude agent with a capability that needs to be reusable across multiple teams in the organization, with each team able to invoke and use it independently. How would you build the capability? | – | |
| 29 | Your Claude application has been running for several conversation turns, and you notice the model occasionally references information that was discussed many turns ago but is no longer relevant. You suspect context drift is causing the model to weight stale content too heavily. How would you address the drift? | – | |
| 30 | You are building a Claude application that processes 10,000 customer emails overnight to extract structured data. The work is non-interactive, runs once daily, and has a flexible completion window of several hours. Which Claude API would you use? | – | |
| 31 | A teammate has asked you to explain when a Skill would be the right choice over an MCP server. The teammate is unsure how the two differ in practice when both can be reused across teams. How would you explain the distinction? | – | |
| 32 | You are building a Claude application that needs to deliver model output to end users as it is generated, instead of waiting for the full response to complete. The Claude API mechanism you would use is ... | – | |
| 33 | You are implementing a custom tool for your Claude agent. The tool needs to interact with an external pricing service that returns product data. Which of the following best practices would you apply as you develop this tool? | – | |
| 34 | You are choosing a Claude model for a high-volume classification task. Each classification is straightforward, latency requirements are tight, and per-request cost matters at scale. Which model would you choose? | – | |
| 35 | Your Claude application is producing inconsistent outputs for similar inputs, even when using the same model and prompt. You want to debug the issue systematically. Your debugging approach would ... | – | |
| 36 | You are designing an agent that handles a complex claim-processing workflow. Each claim moves through fact extraction, eligibility evaluation, and a decision step. The three subtasks have distinct success criteria, and some claims require iteration between fact extraction and eligibility evaluation before a decision can be reached. Which agent pattern would you apply? | – | |
| 37 | You are reviewing an architectural diagram for a Claude-powered travel-booking system. The diagram shows a top-level component that interprets user requests and three subordinate components that handle flights, hotels, and ground transportation. The top-level component is responsible for routing each request, sequencing the subordinate components, and reconciling their outputs into a final itinerary. The diagram also shows that each subordinate component has its own tool list and own short conversation history that is not shared with the others. Which architectural pattern does this diagram most closely describe? | – | |
| 38 | You are designing a Claude application that processes user-submitted text. Some of that text could include sensitive information such as account numbers or passwords that the application should not send to Claude. How would you design the application? | – | |
| 39 | The team is debating whether to build a new capability as a custom tool or to use an existing built-in tool that nearly covers the use case but lacks one specific feature. How would you decide? | – | |
| 40 | Your Claude application receives untrusted input from external sources. The team is establishing how the application should treat this untrusted input. Untrusted input would be... | – | |
| 41 | Your team is preparing a new Claude application for production, and the product team has asked for a cost projection. The team needs to estimate the cost based on expected request volume, average input length, and average output length. How would you build the projection? | – | |
| 42 | Your Claude agent has too many tools, and many of them have overlapping functionality. The agent often picks an inappropriate tool when several could plausibly handle a request. How would you address the tool selection problem? | – | |
| 43 | You are designing an agent that handles a multi-step research task. You want the agent to break the task into smaller pieces, hand each piece to a focused subagent, and consolidate the results. The agent pattern you would apply is ... | – | |
| 44 | Your team uses several plugins across multiple Claude applications, and a recent plugin update introduced a regression. The team had not been tracking plugin versions, so the team cannot easily identify which version was previously working. How would you address this? | – | |
| 45 | You are designing an agent that processes vendor invoices. The work involves a small number of well-understood steps, but occasionally an invoice arrives in an unexpected format that requires the system to decide between rerouting, requesting clarification, or flagging for human review. The most appropriate architecture for this system is... | – | |
| 46 | Your Claude application’s content policy specifies categories of content it should not produce under any circumstance. The application currently has no mechanism to enforce this policy, and content matching these categories is appearing in the application’s output. How would you enforce the content policy? | – | |
| 47 | You are starting a new Claude application and have a small set of well-labeled examples that demonstrate the desired output format. You want to use these examples to guide Claude’s behavior. How would you guide the application’s behavior? | – | |
| 48 | You are setting up a Claude application that will run a mix of multi-turn conversations and one-off requests. You want to use caching techniques to reduce token costs where they apply. A teammate suggests caching the model’s output as well, so the application does not have to make duplicate Claude calls when similar queries arrive. You would apply prompt caching to ... | – | |
| 49 | Your team’s Claude application has been in production for a year, and the team has decided to formalize its testing strategy. Currently, the team writes ad-hoc tests for individual features but has no overall testing approach. What testing approach would you formalize? | – | |
| 50 | A teammate has asked you to explain why the team’s Claude application is billed for output tokens at a different rate than input tokens. They had assumed the rate was the same for both. How would you explain the difference? | – | |
| 51 | A Claude application is occasionally refusing to answer questions that should be in scope, including questions the application has answered correctly in the past. You want to investigate. What is the first step of your investigation? | – | |
| 52 | A Claude application is producing outputs that drift away from the expected JSON format after several conversation turns. The first few turns produce correctly formatted output, but later turns gradually lose structure. How would you address the drift? | – | |
| 53 | A Claude application that worked well in testing is now occasionally returning outputs that mention information not present in the input. The development team initially assumed the model was hallucinating, so they asked you to troubleshoot. What would you do first? | – | |
| 54 | A new agent your team built handles customer support tickets, but it routinely gets confused when a single ticket spans billing, shipping, and product issues. The agent often loses track of which sub-issue it has already addressed and revisits the same one. The team is considering architectural changes. What architectural change would you recommend? | – | |
| 55 | A team has deployed a multi-agent system in which a primary agent decomposes user requests and delegates subtasks to three specialized subagents: one for data retrieval, one for analysis, and one for report generation. In production, the team observes that subagents are making redundant tool calls, occasionally exceeding token budgets, and sometimes producing outputs that contradict each other – all of which the primary agent passes along without catching. What is the most appropriate way to address these failures? | – | |
| 56 | A teammate has asked how the Claude SDK handles transient API errors, such as a temporary network issue or a brief rate-limit response. They want to know whether the application code needs to handle every transient error or whether the SDK provides any default behavior. How would you describe the SDK's default behavior? | – | |
| 57 | A teammate has asked how to extend Claude Code with a custom Skill that the team can invoke during sessions. The Skill consists of a set of instructions and a few support scripts the team wants Claude to be able to call when the Skill is loaded. Where is the right place to define the Skill? | – | |
| 58 | The Anthropic API deprecated a request parameter that your Claude application uses in approximately 40 places across the codebase. The deprecation notice gives a six-month window before the parameter is removed and recommends a replacement parameter with slightly different semantics. You would respond to the deprecation by ... | – | |
| 59 | The Claude application your team built has grown over six months, and the prompt-handling code has accumulated duplication and tangled control flow. The functionality is working, but new features are getting harder to add. How would you address this? | – | |
| 60 | The product team has asked you to choose a Claude model for a new feature. The team has provided functional requirements but has not specified performance, cost, or quality targets. The team's product manager says, "Use whatever model gives us the best results." How would you respond? | – | |
| 61 | The product team has described a new Claude feature in business terms: “agents should help our analysts produce client memos faster.” You need to convert this into actionable technical requirements for the engineering team. Your first step would be to ... | – | |
| 62 | The team is debating whether to integrate with the Claude API directly or through a third-party abstraction layer that supports multiple LLM providers. The team has identified that all current and projected use cases run on Claude, no internal customer has requested LLM portability, and the team’s product roadmap does not mention multi-provider support over the next two years. The third-party abstraction would add roughly 15 percent overhead in code complexity and introduce one additional dependency. Which integration approach would you recommend? | – | |
| 63 | You are building an MCP server that exposes several internal data sources as MCP resources. The server needs to be deployed so multiple Claude applications can integrate with it. How would you approach the build and deployment? | – | |
| 64 | You are choosing between using STDIO-based communication and HTTP-based communication for an MCP server. The server will be invoked by a Claude Code session running locally. Which communication pattern would you use? | – | |
| 65 | You are configuring Claude Code for a new project. The team needs to set permissions, default model selections, and environment-specific behavior at the project level so the configuration is consistent across all developers working on the repository. The Claude Code mechanism you would use is ... | – | |
| 66 | You are deciding between deploying a Claude-powered agent on Anthropic's hosted infrastructure or self-hosting under a "bring your own cloud" model in your own AWS account. The agent processes customer data subject to your enterprise's data residency policies, but the team wants to ship quickly and avoid managing infrastructure. Which deployment model would you recommend? | – | |
| 67 | You are designing a Claude application that helps medical researchers analyze multi-step clinical case studies. The application must work through differential diagnoses by considering symptom patterns, weighing evidence across competing hypotheses, and showing intermediate reasoning steps before producing a final recommendation. The team is choosing among Claude's available model options. The model option best suited to this use case is... | – | |
| 68 | You are designing a Claude application that maintains user sessions across multi-turn conversations. The product team has asked how the application will handle session lifecycle: when sessions should expire, how state is reset, and how the application avoids carrying stale context into new conversations. How would you design session lifecycle? | – | |
| 69 | You are designing a Claude application that will process customer support tickets in two stages: a triage stage that classifies tickets and a response stage that drafts replies. The team is debating whether to use a single Claude call that handles both stages or separate Claude calls for each stage. How would you structure the application? | – | |
| 70 | You are designing a Claude application that will require structured JSON output for downstream processing. The output schema is well-defined, and downstream systems will reject malformed JSON. Your application design would ... | – | |
| 71 | You are designing a multi-step Claude workflow where some steps must reason without seeing the full prior conversation history. The team wants to keep specific context isolated to specific steps. The context engineering technique you would use is ... | – | |
| 72 | You are explaining to a stakeholder why running the same Claude prompt twice can produce slightly different results. The stakeholder is concerned this means the application is broken. How would you address the stakeholder’s concern? | – | |
| 73 | You are integrating Claude into an application written in Python. The Claude SDK provides a Python client that wraps the underlying REST API. How would you integrate the SDK? | – | |
| 74 | You are setting up a CI/CD pipeline for a new Claude application. The pipeline needs to run automated checks on every pull request before code can be merged. The CI/CD checks would include... | – | |
| 75 | You are setting up a Claude application that requires API keys for several external services. What is the best way to store the keys? | – | |
| 76 | You are setting up Claude Code for a new project repository. Your team has shared coding standards, preferred libraries, and project-specific context that every developer working on the repository should have available when they use Claude Code. How would you set this up? | – | |
| 77 | You are setting up the configuration management approach for a new Claude Code project. Your team will use CLAUDE.md files and settings.json files to control behavior, and you want to make sure changes are tracked and reviewable. The configuration management approach would ... | – | |
| 78 | You maintain a Claude application that uses Claude Sonnet 4.5 across several production workflows. Anthropic released Claude Sonnet 4.7, which your evaluation suite shows performing 8% better on your highest-volume task. However, this version produces different output formatting on two of your structured-extraction prompts that downstream consumers parse with regex-based code. To roll out the upgrade, you would... | – | |
| 79 | Your agent is processing tasks that take 30 to 60 minutes to complete. Each task has well-defined intermediate checkpoints, and the team wants the agent to be able to resume from the most recent checkpoint if a process is interrupted. How would you implement this resumability? | – | |
| 80 | Your Claude agent has access to a tool that retrieves customer records. A teammate has noticed that the agent occasionally calls the tool with arguments the schema does not declare, and the tool’s downstream service returns an error each time. The teammate proposes loosening the schema so the tool accepts whatever arguments the model produces. How would you respond? | – | |
| 81 | Your Claude agent performs database operations. A recent incident occurred where the agent ran a destructive query that affected production data. The team wants to add deterministic controls to prevent similar incidents. How would you prevent similar incidents? | – | |
| 82 | Your Claude agent’s hooks are currently triggered for every action, which slows down the agent significantly even when actions pose no risk. The team wants to scope hooks more carefully. How would you scope the hooks? | – | |
| 83 | Your Claude application is deployed to development, staging, and production environments. Each environment uses a different model version, different prompt versions, and different plugin dependencies, but the configuration is currently scattered across environment variables, hardcoded values, and undocumented setup scripts. How would you manage the configuration? | – | |
| 84 | Your Claude application makes high-volume API calls during business hours and very few calls overnight. The team is concerned about staying within rate limits during peak hours and wants to understand how the Claude API enforces those limits. How would you proceed? | – | |
| 85 | Your Claude application processes 50-page legal contracts and produces summaries with citation references back to the source. The team is debating whether to send each contract whole or split into smaller pieces. The contracts fit within Claude’s context window. Initial testing shows that whole-document processing produces summaries with stronger cross-section reasoning but occasionally drifts on citation accuracy in later sections. Chunked processing produces stronger citation accuracy per chunk but loses cross-section reasoning. The team has not decided which property matters more. How would you guide the team’s decision? | – | |
| 86 | Your Claude application returns confident-sounding answers, but occasionally those answers contain factual errors that downstream systems treat as ground truth. The team is concerned about the application's confidence-versus-accuracy gap. How would you address the gap? | – | |
| 87 | Your Claude application’s API keys are stored in a secrets manager. The team is debating whether the same key should be used in development, staging, and production environments. How would you handle the keys across environments? | – | |
| 88 | Your Claude application's outputs are inconsistent in format. The team's instructions are scattered across the system prompt and user messages, with some instructions stated only once and others repeated. How would you fix the inconsistency? | – | |
| 89 | Your Claude application's token costs have grown faster than expected. The team has not been tracking token usage by feature, so the team cannot identify which features are driving cost. The team is debating how to respond. How would you respond? | – | |
| 90 | Your Claude application uses tool calling to fetch patient data and generate summary reports. The flow occasionally fails because the model returns a tool_use block that references arguments not present in the schema, and your application code does not handle this case gracefully. How would you address this? | – | |
| 91 | Your Claude application validates structured output but has been treating validation failures as terminal errors. Each validation failure causes the entire user request to fail. The team wants to handle validation failures more gracefully. How would you handle the validation failures? | – | |
| 92 | Your enterprise has a contract with AWS that requires Claude API calls to flow through Amazon Bedrock rather than the direct Anthropic API. Your team is building a new Claude application and is unfamiliar with this constraint. How would you build the application? | – | |
| 93 | Your team is choosing how to add a capability to a Claude application. You want to apply the appropriate option, whether built-in tool, custom tool, Skill, or MCP server, based on the use case. You would choose the option that... | – | |
| 94 | Your team’s Claude agent has accumulated several customizations that bypass the SDK’s defaults, including custom history management, retry logic, and error handling. A new team member has proposed reverting all the customizations to maintain the codebase more easily. The tech lead disagrees and says each customization was added for a reason. How would you advise the team? | – | |
| 95 | Your team uses Claude Code across multiple repositories. You want the team’s rules and general coding standards to apply to all repositories, and other rules to apply only to specific repositories. The team is currently duplicating instructions across every repository’s CLAUDE.md file. How would you address this? | – |