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Start with a production system
Follow a real architecture as load, latency, consistency, and failure pressure reshape it.
Production system design
Stop memorizing architecture diagrams.
Learn to reason about systems when they are slow, overloaded, inconsistent, or failing.
Start with a production system. Open the concepts underneath. Reuse the patterns that fix it.
Choose your starting point
Tell Arcflow why you opened the tab.
Pick the reason that matches your current pressure: interviews, production systems, concepts, or reusable patterns.
I want to get better at system design interviews
Start with recognizable systems and learn how to explain the pressure behind each design choice.
Open system studies
I want to understand production backend systems
See how simple services change when latency, load, stale data, retries, and failures show up.
Start with URL shortener
I want the concepts underneath the architecture
Build the vocabulary behind real design decisions: caching, queues, replication, indexing, and backpressure.
Open concepts
I want reusable patterns I can apply
Study the moves engineers reuse for consistency, async workflows, failure isolation, and repair paths.
Open patterns
Core pillars
System design starts when the simple version breaks.
arcflow teaches the loop real engineers use: study the production system, understand the concepts underneath it, then reuse the patterns that make the design survive pressure.
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modules
Production System Design
Start with real products and watch the simple design break under traffic, latency, consistency, and failure pressure.
URL ShortenerChat System
Explore Production System Design
47
modules
Concepts
Open the ideas underneath each decision: caching, queues, indexes, replication, idempotency, and backpressure.
CachingReplicationBackpressure
Explore Concepts
17
modules
Patterns
Reuse proven architecture moves for fan-out, rate limiting, reconciliation, consistency, and failure isolation.
OutboxFan-OutCircuit Breaker
Explore Patterns
Open a study
Begin with a real system, then follow the links deeper.
The fastest way into arcflow is not a list of definitions. Start with a system study, then open the concepts and patterns that explain each design move.
System Design
URL Shortener System
Design a reliable URL shortening service that supports short-code generation, low-latency redirects, abuse controls, analytics, and horizontal scaling.
CachingRate LimitingAnalytics Pipelines
System Design
Instagram Likes System
Design a production-grade like system that handles retry-safe mutations, hot posts, distributed counters, fan-out, derived projections, and eventually consistent read models.
IdempotencyDistributed CountersFan-Out
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Open the concepts underneath
Learn the mechanics behind each decision: queues, caches, indexes, replication, and retries.
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Reuse the patterns that fix it
Carry proven design moves into new systems instead of memorizing diagrams.