Intermediate~2h
Structured Outputs & Function Calling in LLM CoreInterview Readiness Check
JSON mode vs constrained decoding vs function calling — the modern reliability story for LLM outputs. Schema design, retries, validation, parsing failures..
function callingtool useJSON modestructured outputconstrained decodingschemaZodPydantic
Learning path
Prompt Engineering — Opinionated→Structured Outputs & Function Calling ← you are here→Streaming & Realtime UXTool / Function Calling Deep-DiveVision, Audio & Multimodal LLMs
Try a sample question
A backend service needs to parse LLM responses into a database record. The LLM sometimes wraps JSON in markdown code blocks (```json ... ```) and sometimes returns plain JSON. Which approach eliminates this inconsistency?
A.Add 'return only JSON, no markdown' to the prompt and write a regex to strip code blocks as a fallback
B.Use temperature=0 to make the output deterministic
C.Use the provider's JSON mode or structured output API — the model is constrained at the token level to emit valid JSON, eliminating markdown wrapping
D.Post-process with JSON.parse and retry on failure
Sign up free to take the full check and see the answer with an explanation.
What this module tests
- Conceptual understanding of structured outputs & function calling fundamentals
- Trade-offs and design decisions in real system scenarios
- function calling and tool use — applied knowledge
- Interview-style reasoning and explanation quality
Free to start
Take the Structured Outputs & Function Calling check →
10 questions · Dimension scoring · AI coach feedback · Shareable result
Test your knowledge — free →No credit card · Takes 10–15 min
Frequently asked questions
- What does the Structured Outputs & Function Calling check test?
- The check covers json mode vs constrained decoding vs function calling — the modern reliability story for llm outputs. schema design, retries, validation, parsing failures.. Questions span beginner to advanced difficulty and test both conceptual understanding and practical trade-off reasoning.
- What keywords should I know for Structured Outputs & Function Calling?
- Key concepts include: function calling, tool use, JSON mode, structured output, constrained decoding, schema, Zod, Pydantic. These frequently appear in llm core interviews at product and infrastructure companies.
- How many questions are in the check?
- Each check has 10 questions — a mix of MCQ and short-answer. You get scored by dimension (e.g., scalability, consistency) so you know exactly where to focus.
- How long does it take to study Structured Outputs & Function Calling?
- Most engineers spend around 2 hours on this module. The check itself takes about 10–15 minutes. You can retake it up to 3 times per day.
- What prerequisite knowledge do I need before Structured Outputs & Function Calling?
- Structured Outputs & Function Calling builds on Prompt Engineering — Opinionated. Complete those first for the best results.
- Is function calling, tool use, JSON mode covered?
- Yes. The Structured Outputs & Function Calling module covers function calling, tool use, JSON mode among other key concepts. The check includes questions that reflect real llm core interview patterns.