I Built a Self-Hosting Language, a DB Engine and a Microkernel — Entirely on My Phone

A developer has built SahajCore, a self-hosting programming language, along with a database engine and a microkernel, entirely on an Android phone using Termux. The project includes a bytecode compiler, a stack VM, and transpilers to C and WebAssembly, with the interpreter written in SahajCore itself. The developer shared the project on GitHub and is open to discussing the implementation details.

No laptop. No IDE. Just Termux and a text editor. Over the past year I shipped five systems from my Android phone: Here's how the core works. The pipeline is classic: source → tokenizer → recursive-descent parser → AST → tree-walk interpreter → bytecode compiler → stack VM → C / WAT transpilers The bytecode compiler emits a flat instruction list. This is real output from sahajcore --compile : 0004 LOAD a 0005 LOAD b 0006 CONST 2 0007 BIN 0008 BIN + 0009 STORE c 0014 BIN 0015 JZ 19 The interpreter is written in SahajCore itself. The bootstrap chain: Python-hosted interpreter → runs selfhost.sahaj interpreter written in SahajCore → runs target.sahaj user program The hardest bug: recursive Fibonacci blew the Python stack because every target-level call expanded into hundreds of host frames. Fix: rewrote the demo iteratively and raised the recursion limit. A tiny relational engine with: pip install sahajcore pip install sahajql GitHub: github.com/sayan9168/SahajCore Happy to go deep on any part — ask me anything.