Distributed background job library and service backed by PostgreSQL. Solves the dual-write problem via transactional enqueueing (`EnqueueTx`), uses `FOR UPDATE SKIP LOCKED` for atomic worker claiming, and handles crash recovery via heartbeats and a background reaper (~148 tasks/sec under k6 load).

Standalone SQL migration runner and CLI for `pgx/v5`, extracted from Dhara. Enforces schema immutability via SHA-256 checksum drift detection, uses PostgreSQL advisory locks for concurrent deploy safety, and embeds via `io/fs`.

Published Python rate-limiting package (`pip install volter`) implementing Token Bucket and amortized O(1) Sliding Window Log algorithms. Uses two-level lock-free read paths in memory and atomic server-side Lua scripts in Redis, with FastAPI ASGI middleware.

Zero-dependency Redis server in Java using virtual threads. Profiled with `async-profiler` flame graphs to eliminate syscall and allocation bottlenecks, driving a 70x speedup to 84,000 ops/s across 36 commands, RESP protocol, pub/sub, and master-replica replication.

Full-stack URL shortening service with sub-millisecond cached redirects, JWT authentication, and click analytics.

Tree-walk interpreter for the Lox language built from scratch in Go, covering lexical analysis, AST parsing, and environment evaluation.

POSIX-compliant shell implementation in Java handling command parsing, PATH resolution, builtins, and process execution.