A trajectory for low-latency event systems where ordering, deduplication, and user-visible correctness are critical.
Completion0%
Target role
Engineers preparing for realtime platform and data-intensive interview loops.
Current focus
Step 1: Realtime Messaging Fundamentals
Progress mode
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Step 1CurrentadvancedPremium
Real-Time Chat & Messaging System
Design a globally distributed chat platform with low-latency delivery, offline sync, read receipts, media attachments, and strong consistency guarantees for message ordering.
Why now
Establishes delivery semantics and fanout design for user-facing realtime systems.
Design a globally distributed presence platform that tracks online/offline state for millions of users with low-latency fanout, privacy controls, and replay-safe reliability.
Why now
Adds soft-state design and consistency constraints under bursty connection churn.
Design a real-time leaderboard system that serves millions of players with p99 rank reads under 80ms, handles 1.2M score updates/sec, and enforces explainable anti-cheat decisions.
Why now
Combines streaming writes, ranking correctness, and abuse response mechanisms.
Event Deduplication Platform for Idempotent Processing
Design a platform that removes duplicate events across distributed pipelines with low latency.
Why now
Forces precise reasoning on dedup windows, replay behavior, and storage tradeoffs.
Skills learned
Idempotency key designReplay-safe writesDedup state lifecycle
Step 5UpcomingbeginnerPremium
Event Replay Platform for Debugging Microservices
Design an event replay platform that allows developers to capture, store, and replay events from microservices for debugging and testing purposes. Enable time-travel debugging across distributed systems.
Why now
Deepens operational debugging and causality reconstruction for microservice systems.