Build System Designs
Feature by Feature

Build a video platform feature by feature: upload, transcode, stream, recommend, and go live.

Build a microblogging platform feature by feature: tweet creation, timeline, search, trending, notifications, DMs, media, ads, Spaces, and analytics.

Build an encrypted messaging platform feature by feature: messages, groups, encryption, media, calls, stories, presence, backups, and payments.

Build a photo-sharing platform feature by feature: upload, feed, stories, reels, explore, DMs, live, shopping, notifications, and search.

Build a ride-sharing platform feature by feature: ride requests, location tracking, matching, pricing, payments, navigation, notifications, ratings, safety, and analytics.

A marketer needs to track 10K campaign links across social media, email, and ads. Build a URL shortening service that creates, redirects, analyzes, and scales.

Black Friday sale triggers 50M notifications in 30 minutes. Build a multi-channel notification platform that delivers reliably at massive scale.

Google needs to index 50 billion web pages across millions of domains. Build a distributed web crawler that discovers, fetches, parses, and indexes the internet.

Build a streaming platform: video ingestion, transcoding, CDN delivery, recommendations, profiles, search, downloads, playback, billing, and analytics.

Build a music streaming platform: audio ingestion, streaming, search, playlists, recommendations, offline, social, podcasts, ads, and payments.

Build a collaborative editor: real-time editing, conflict resolution, version history, and sharing.

Build a workspace messaging platform: channels, threads, search, file sharing, and integrations.

Build a dating platform: profile cards, swipe matching, geolocation, and recommendations.

Build a payment platform: tokenization, processing, fraud detection, refunds, and reconciliation.

Build a distributed rate limiter: algorithms, state management, quotas, and monitoring.

Build a food delivery platform: restaurant search, ordering, payments, delivery tracking, and analytics.

Build a hotel booking platform: search, availability, reservations, and dynamic pricing.

Build a production distributed cache from scratch: consistent hashing, replication, eviction, read/write patterns, invalidation, monitoring, and cluster management.

Build a ticket booking system: events, seat selection, holds, payments, and waitlists.

Build a battle-tested leaderboard system handling 100M+ players: atomic score updates, real-time ranking, pagination, social graphs, time-based resets, anti-cheat, notifications, and analytics.

Build an AI agent from scratch — LLM brain, tools, memory, and planning. Like Devin or AutoGPT.

Build a Q&A bot over your company docs -- ingest, chunk, embed, retrieve, and generate. Like Glean or Perplexity.

Build a supervisor agent that coordinates a research team -- specialist agents for search, writing, and review. Like LangGraph or CrewAI.

Build a Q&A bot over your company docs -- ingest, chunk, embed, retrieve, and generate. Like Glean or Perplexity.

Build a supervisor agent that coordinates a research team -- specialist agents for search, writing, and review. Like LangGraph or CrewAI.

Build an agent that turns "Plan a 5-day Goa trip for 2 under ₹50k" into a real booked itinerary — parsing intent, calling flight/hotel/weather APIs, and safely confirming bookings.

Build a Cleo/YNAB-style agent that reads your bank transactions, flags overspending, and safely suggests actions — with strict PII and human-in-the-loop guardrails.

Build a Devin/Cursor-style agent that writes, runs, and tests real code inside an isolated sandbox — with safe rollback and human approval before merging.

Build an Intercom Fin-style support bot — grounded in help-center docs, capable of taking safe actions, escalating frustrated users, and measuring deflection.

Talk to your data. Upload CSVs or connect a warehouse, ask questions in English, get charts + answers. Like Hex Magic or ChatGPT Code Interpreter.

Zapier / n8n-style: "when new Stripe payment, post Slack + update Google Sheet." Triggers, actions, DAGs, retries.

Ramp-style: extract structured data from invoices, contracts, receipts. OCR + layout + LLM + human review.

TikTok/Meta-scale moderation: hash match, ML classifiers, LLM for nuance, humans for hard calls. Cheap first, smart last.

Screen 10,000 resumes the way Eightfold and HireVue do — parse PDFs, match against the job, kill bias, and hand the top candidates to a human recruiter.

Build an Ada-Health-style symptom checker. Capture symptoms, catch life-threatening red flags with hard rules, ground every suggestion in a medical knowledge base, and stay HIPAA + FDA compliant.

Build an Amazon Rufus / Flipkart Nova-style shopping agent. "Gift for my wife's 30th under ₹5k" → parse intent, retrieve candidates, personalize, and ONLY suggest SKUs that actually exist and can ship.

Build a Motion / Reclaim / x.ai style scheduler. "Find 30min with Priya and Raj next week, preferably morning" → parse, pull calendars safely, solve across timezones, and atomically book across Google + Outlook.

Build a Perplexity / ChatGPT Deep Research clone — takes a big question, plans sub-queries, pulls from many sources, ranks credibility, and writes a cited report.

Build an SRE copilot (like Resolve AI / Cleric / PagerDuty AIOps) that ingests alerts, guesses root causes, investigates safely, and proposes a fix with human approval.

Build a 1:1 AI tutor like Khanmigo or Duolingo Max — tracks what the student knows, guides with Socratic questions instead of giving answers, picks the next problem, and stays safe for kids.

Build a HomeKit / Alexa / Home Assistant clone — "I am going to sleep" should turn off lights, lower the thermostat, and lock every door reliably, even if the internet is down.

Design a multi-floor parking lot with vehicle hierarchy, spot management, and fee calculation

Design an elevator system with scheduling algorithms, state machines, and multi-elevator coordination

Design the classic snake game with board management, movement, collision detection, and game loop

Design tic-tac-toe with board, players, win detection, and game flow control

Design a library system with book catalog, member tiers, lending, and fine calculation

Design a vending machine with state management, coin handling, and inventory tracking