This Concurrency Bug Stayed Hidden for a Year
A deep dive into a subtle concurrency bug that evaded detection for over a year, exploring the root cause, debugging process, and lessons learned for building more robust systems.
Harshit Singhal
Backend engineer writing about API architecture, authentication, and real-world system tradeoffs.
Blog
Projects
envdiff
Open source CLI tool that catches .env config drift
before it breaks your team. Detects missing keys, stale variables,
and mismatched values between .env.example and
.env — with zero dependencies and no data leaving your
machine.
ReAct Agent Framework
Production-style ReAct agent framework with pluggable tool registry, Gemini/Ollama provider abstraction, SSE-based reasoning trace streaming, and JWT-based ABAC authorization for tool-level access control.
About
I work on backend systems where API design, auth boundaries, and runtime behavior directly affect reliability. Most writing here is about practical tradeoffs in production systems.