xpr-lang
A sandboxed expression language with byte-identical runtimes in TypeScript, Python, and Go.
- TypeScript
- Python
- Go
- Parser theory
- EBNF
- VitePress
- +2
~ shahadulhaider/portfolio
Muhammad Shahadul Haider
Lead Engineer · Multi-tenant SaaS & developer tools · 10+ years of Python, Go, TypeScript
Software engineer with 10+ years building data systems, multi-tenant platforms, and developer tools in Python, Go, and TypeScript. Currently lead engineer on a multi-tenant SaaS platform - owning architecture and end-to-end delivery from Postgres schemas and CI pipelines through React frontends. Author of xpr-lang, a sandboxed cross-runtime expression language with byte-identical implementations in TypeScript, Python, and Go, shipped to npm, PyPI, and Go modules.
what i'm building
Featured projects
A cross-runtime expression language, terminal-native developer tools, and full-stack product builds.
restless
Your API workbench lives in the terminal.
$ brew install shahadulhaider/tap/restless
- Go
- Bubble Tea / Charm
- *.http file format
- JavaScript (ES5.1) scripting
- Postman / Insomnia / Bruno / OpenAPI import
repo
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envdiff
Compare, validate, and sync .env files across environments.
$ brew install shahadulhaider/tap/envdiff
- Go
- Bubble Tea
- TOML schemas
- pre-commit
- GitHub Actions
repo
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ports
Keyboard-driven TUI for exploring listening ports on macOS and Linux.
$ brew install shahadulhaider/tap/ports
- Go
- Bubble Tea
- Lip Gloss
- lsof / netstat parsing
repo
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where i've worked
Recent experience
Three most recent roles. The full timeline lives on the resume page.
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2025 — Present
Lead Engineer · BengalByte
Lead engineer on a multi-tenant SaaS platform - driving technical direction and end-to-end delivery of core subsystems across the Python / FastAPI backend and Next.js 15 / React 19 frontend.
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2024 — 2025
Senior Software Engineer · FlowGenX AI
Architected a multi-tenant Kubernetes deployment service and a low-code data integration platform for orchestrated workflows.
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2023 — 2024
Senior Full Stack Engineer · Cognitus
Built an enterprise SAP data migration platform and a real-time analytics dashboard for 15+ enterprise clients.
recent writing
From the blog
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·- #ui/ux
- #productivity
- #computing history
The Evolution of Computer Shortcuts: From Terminal Commands to Touch Gestures
A journey through six decades of human-computer interaction design, from cryptic terminal commands to intuitive touch gestures, and what it teaches us about interface design.
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·- #go
- #concurrency
- #performance
Beyond Goroutines: Advanced Concurrency Patterns in Go
Dive into advanced Go concurrency patterns beyond basic goroutines and channels, with practical examples and performance considerations for real-world applications.
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·- #kubernetes
- #go
- #multi-tenancy
Building Multi-Tenant Kubernetes Deployments in Go
How to build a secure, scalable multi-tenant Kubernetes deployment service using Go, addressing isolation, resource management, and security challenges.