Infra · AI System Designsenior

AI Coding Copilot (Inline Completion at Scale)

Components

Drag onto the canvas, or click to add.Tap to add to the canvas.

Utilities

Text Box

Group / Container

Circle

Diamond

Divider Line

Heading

Recommended

Client / User

LLM / Model

Model Router

Cache (semantic/prompt)

PII Filter / Redactor

Observability / Tracing

Entry & gateway

Client / User

LLM Gateway

API Gateway

Orchestration

Orchestrator / Planner

Agent / Worker

Agent Loop

Models

LLM / Model

Model Router

Embedding Model

STT / TTS

Retrieval / RAG

Retriever

Reranker

Vector Store

Knowledge Source

Tools & execution

Tool / Function

MCP Server

Code Sandbox

Browser / Computer Env

External API

Memory & state

Working Memory

Long-Term Memory

Cache (semantic/prompt)

Safety & eval

Guardrail / Classifier

PII Filter / Redactor

Eval / Judge

Observability / Tracing

Infra & data

Database / State

Queue / Event Bus

Human

Human-in-the-Loop

Drag or click a component on the leftTap Components to add your first piece

connect · iterate · submit for review

// brief

AI Coding Copilot (Inline Completion at Scale)

Design the inline gray-text code-completion system for millions of developers — instant, cheap, and high quality.

Key Requirements

01Sub-few-hundred-ms latency (debounce, cancel, small model, caching)
02Context assembly under a token budget (open/nearby files, LSP)
03Retention (not just acceptance) as the quality signal
04Cost control at high QPS; privacy (no-retention / on-device option)
05Load shedding under pressure; never send detected secrets

Rubric must-haves

0/3

Has a cache for prefixes/completions
Has a model (ideally small/fast tier)
Has a secret/PII filter on context

These checks are the structure score, 30% of your total. They update as you draw.

Practise it like the real round

45-minute timer paced through requirements, design and deep dive. The follow-up questions stay hidden until the last phase, and solution hints are off.

AI Review

0/5

Review me as:

Build your design, then submit for an AI-powered review with dimension scores, strengths, gaps, and actionable suggestions.

Try designing your solution first before viewing hints.

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