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Build a DNS Resolver in Python From Scratch
Build a recursive DNS resolver in Python with TTL caching. Learn the Chain of Responsibility pattern and how CoreDNS, Route53, and dig work under the…
Apr 10
•
Sharon Sahadevan
Build a Load Balancer in Python From Scratch
Build round-robin, weighted, and least-connections load balancing in Python. Learn the Strategy pattern and how nginx, HAProxy, and Kubernetes route…
Apr 3
•
Sharon Sahadevan
March 2026
Build a Rate Limiter From Scratch in Python
Implement fixed-window, sliding-window log, and token-bucket rate limiting in Python. Learn which algorithm to pick and why.
Mar 27
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Sharon Sahadevan
Why Redis Uses C, Not Python: The GIL Explained
Your MiniRedis has a hidden bottleneck. Understanding it is the difference between a junior and senior answer in system design interviews.
Mar 20
•
Sharon Sahadevan
1
Implement TTL and Key Expiry in Python From Scratch
Two expiration strategies, one min-heap, and the clever trick Redis uses to expire millions of keys without freezing
Mar 13
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Sharon Sahadevan
Build a Key-Value Store in Go
Build a Redis-like key-value store in Go with TTL, HTTP API, and goroutine-safe concurrency. Includes Python vs Go comparison.
Mar 7
•
Sharon Sahadevan
2
Redis Persistence in Python: WAL & Snapshots From Scratch
Your key-value store survives restarts — using the exact same techniques Redis, PostgreSQL, and Kafka use under the hood
Mar 6
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Sharon Sahadevan
February 2026
Build Your Own Redis in Python: Key-Value Store From Scratch
Why every DevOps engineer already understands Redis internals — and how to prove it in a coding interview
Feb 28
•
Sharon Sahadevan
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