Md Sajjadur Rahaman

1. Full Stack EngineerKuala Lumpur, Malaysia

   October 2023 – Present

   • Sole engineer on a ground-up rewrite of the company's project-management SaaS API: Laravel 13 / PHP 8.3 on PostgreSQL 17, built as a modular monolith of 8 bounded modules communicating through domain events, exposing 120 documented endpoints across 55 tables with 69 Pest test suites and a generated OpenAPI specification.
   • Designed an LLM agent that converts WhatsApp conversations into tasks, notes, and files under human-in-the-loop approval, built as a ports-and-adapters layer over six providers (OpenAI, Anthropic, Azure OpenAI, Bedrock, Cohere, Gemini) that degrades to a deterministic heuristic driver when no API key is configured.
   • Made the agent's delivery path survive failure: a transactional outbox over Redis Streams consumer groups with a dead-letter stream, lease and claim semantics, stale-message reconcilers, and separate dispatch and execution retry budgets, sequenced by a documented timeout ladder from LLM call through job to queue worker.
   • Instrumented per-call LLM cost telemetry (provider, model, latency, input and output tokens, and status) written to a dedicated usage table with retention pruning, plus a pre-flight filter that drops trivial chatter before it reaches a paid call.
   • Built the offline-first desktop client (Tauri 2 + Rust, 357 of 366 commits): local GGUF inference through llama.cpp with Metal acceleration, a from-scratch RAG pipeline (MiniLM embeddings, content-hash incremental re-indexing, cosine retrieval), an LRU/TTL semantic response cache, and a LoRA adapter subsystem with on-device training, versioning, and rollback; released for macOS, Windows, and Linux behind a signed auto-updater.
   • Owned build and release: one FrankenPHP image running four process roles (API, queue worker, scheduler, WebSocket) selected at runtime; GitHub Actions CI that lints, tests, and builds the production image on every pull request; and an Azure DevOps pipeline deploying a single codebase to eight white-label customer environments in parallel.

1. Junior Software DeveloperKuala Lumpur, Malaysia

   February 2022 – September 2023

   • Built ID-document OCR into the security-desk visitor check-in flow of a multi-tenant property-management SaaS: webcam capture through cloud OCR across passport, national-ID, and driving-licence endpoints, auto-populating registration fields with graceful fallback to manual entry; shipped over six releases.
   • Contributed 152 commits to a Laravel 9 platform of 102 models, 175 migrations, and 659 routes across four versioned REST APIs, with five auth guards, property-scoped tenancy, four-language localization, and a per-property module enable/disable system gating features per tenant.
   • Owned the iOS build and release process for the companion Flutter app (GetX, 276 Dart files): APNs push, staging and production flavors, iPad layouts, and download and connectivity fixes, running the gitflow release train from v1.0.2 to v1.4.9 across both app stores.
2. Software Engineer InternKuala Lumpur, Malaysia

   September 2021 – January 2022

1. Freelance Full Stack Engineer (Contract)Remote
   • Backend lead on a multi-tenant hotel-management SaaS (345 of 546 commits): Laravel 12 / PHP 8.4 JSON API spanning 62 models, 83 migrations, ~290 versioned endpoints, and 116 service classes, with a four-tier platform/owner/staff/guest access model, per-property RBAC scoping, and plan-and-feature entitlement middleware.
   • Built a pluggable payments layer behind one gateway contract and registry: four drivers (Stripe, Checkout.com, SSLCommerz, manual) with per-gateway client factories and webhook signature verifiers, money and payment-session value objects, and idempotent webhook-event recording, all kept architecturally separate from subscription billing. Backed by 35 dedicated payment test files within a 149-file, 1,030-test suite run against MySQL on every pull request.
   • Delivered white-label custom-domain hosting: domain-verification records with token, status, and timestamp plus a conflict detector on the API, paired with Next.js 16 edge middleware that resolves the incoming Host header to a tenant and injects scoped headers, so one deployment serves every client brand's own domain.
   • Solo-built a multi-branch, multi-country commerce platform (764 of 765 commits): Laravel 12 + Inertia + React 19 + TypeScript with Meilisearch: 79 models, 251 pages, ~230 routes, and 216 test files covering ~1,483 cases, including a lot-allocation rewards ledger, inter-branch inventory transfers with receipts, and an 11-service access-governance subsystem for branch and country scoping.
   • Authored the Docker and Caddy deployment stack reused across three products, with per-environment Compose files, wildcard TLS, and a documented staging-to-production promotion flow.

1. Freelance Web Developer (PHP/Laravel, MySQL, JavaScript)

Offline-first, AI-powered project management and knowledge organization app that combines local LLMs with cloud AI for planning, tasks, and intelligent content linking.

Tech: Tauri 2, Rust, React 19, llama.cpp, RAG / vector search, LoRA / MLX

Backend API platform for property management and clubhouse operations, built on Winter CMS with modular plugins and mobile/web API support.

Tech: Laravel, MySQL, HikCentral IoT, APNs PushKit / FCM, WebSockets

A production-grade backend platform combining secure APIs and real-time fleet streaming to power autonomous shuttle operations.

Tech: Node.js, Socket.IO, MQTT, RabbitMQ, MySQL binlog CDC, Laravel