I'm a results-driven Senior Full-Stack & Mobile Developer with over 4.5 years of full-time professional experience architecting and delivering high-scale SaaS platforms, production-grade APIs, and cross-platform mobile applications serving global user bases. Expert in React / Next.js, Node.js / NestJS, PostgreSQL, React Native, and cloud infrastructure on AWS. I led architecture for a multi-tenant B2B SaaS platform serving 1M+ messages/month, cutting p95 latency from 1.4s → 220ms. Proven in agile delivery, code quality leadership, and cross-functional team mentorship.
My B.Sc. in Mathematics gives me a unique structural advantage — I translate complex logical reasoning and algorithmic thinking directly into clean, efficient, and scalable software systems. I don't just write code; I engineer solutions built to last. My mathematical background feeds into how I approach system design, performance optimization, and debugging complex distributed problems.
🔵 Frontend Architecture I architect seamless, highly performant, and accessible user interfaces using Next.js 14, React.js, and TypeScript. I also have specialized expertise in engineering high-security Manifest V3 Chrome Extensions for enterprise-grade workflow automation — including one-click LinkedIn/Sales Navigator import with OAuth-aligned session continuity and hardened content-script boundaries.
🟠 Backend & Distributed Systems I design and build secure, scalable backend services capable of handling massive data throughput. At LeadSync, I scaled a production inbox to handle 1M+ messages/month, reducing p95 latency from 1.4s → 220ms through Redis-backed queue optimizations and strategic database indexing. My backend stack includes Node.js, NestJS, Prisma, PostgreSQL, MySQL, MongoDB, Redis, and Elasticsearch.
📱 Mobile Ecosystems I take full ownership of mobile product lifecycles, engineering fluid cross-platform apps using React Native and Expo. My published app TakaMinder — a personal finance tracker for Bengali users — features 100% offline-first SQLite storage, conflict-aware encrypted Google Drive backup, and biometric vault protection with zero third-party tracking or ads.
🤖 AI-Integrated Products At VioResume (NYC-based SaaS), I led the full Next.js frontend for an AI-powered resume builder — integrating AI content generation, real-time ATS scoring, smart job-matching with advanced filtering, and dynamic voice-led intake flows. I care deeply about weaving intelligence into UX that actually helps people.
🚢 End-to-End Product Delivery From launching Renesa Bazar (full-scale e-commerce with dynamic PC Builder & Camera Builder configurators, mega-category navigation, and inventory-aware merchandising) to architecting LeadSync's multi-channel B2B outbound automation with CRM sync pipelines for HubSpot, Salesforce, and Pipedrive — I deliver complete products without compromising performance or user experience.
I define API design standards, rate-limiting strategies, and state management patterns across platforms. I mentor engineers through rigorous code reviews, establish WCAG accessibility compliance, maintain high-velocity agile release cycles, and lead zero-downtime migrations (including Next.js 14 App Router migration while maintaining shared API contracts across web, mobile, and Chrome extension simultaneously).
Beyond my professional engineering roles, I am an active contributor to the Deogaon Social Development Forum (DSD Forum), applying my digital organizational skills to lead record-keeping and community development initiatives. I'm constantly adapting — currently exploring AI-augmented engineering workflows, distributed systems patterns, and advanced mobile animations with Reanimated 3.
I am always open to discussing software architecture, performance optimization, mobile product challenges, or innovative tech ideas. Whether it's a collaboration, a freelance project, or just a good engineering conversation — reach out anytime!
📞 +880 1745-296294 | ✉️ masudhossainmbs129@gmail.com | 🌐 devmasud.tech
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May 2025 Present |
🔵 Senior Software Engineer — LeadSync Pte. Ltd. Singapore (Remote)AI-Powered B2B Sales Automation & Lead Generation SaaS • Spearheaded end-to-end architecture of a multi-tenant B2B outbound platform: Next.js 14 frontend, NestJS backend, React Native mobile, and a Manifest V3 Chrome Extension • Scaled production inbox to 1M+ messages/month; reduced p95 latency from 1.4s → 220ms via Redis-backed queue optimizations and database indexing • Built centralized sequencing engine for multi-channel campaigns (LinkedIn + email) with real-time CRM sync for HubSpot, Salesforce, and Pipedrive • Engineered Manifest V3 Chrome Extension with hardened content-script boundaries, one-click LinkedIn/Sales Navigator import, and OAuth-aligned session continuity • Defined API design standards and rate-limiting strategies; mentored engineers through rigorous code reviews ensuring zero-downtime releases |
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Feb 2024 May 2025 |
⚪ Software Engineer — VioResume New York, USA (Remote)AI-Powered Resume Builder SaaS • Led complete Next.js frontend architecture for a public-facing AI resume builder, owning UI from marketing site through the core application flow • Built a complex ATS resume authoring engine: dynamic ATS-optimised templates, real-time previews, drag-and-drop module management, and voice-led intake • Integrated AI-assisted content generation, real-time ATS scoring, smart job-matching with advanced filtering, and instant cover-letter pairing • Established state management patterns ensuring pixel-perfect responsiveness and WCAG accessibility; mentored junior developers in a high-velocity release cycle |
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Jan 2023 Feb 2024 |
⚪ Software Engineer — Codeact Soft. Dhaka, BangladeshFull-Stack Product Development • Led end-to-end development of Renesa Bazar (e-commerce platform) and Hej Care, delivering scalable user-centric products with full backend and frontend ownership • Designed secure RESTful APIs using Node.js, Express, and Prisma ORM over MySQL; optimised data retrieval for high-traffic endpoints • Developed and launched two production-grade cross-platform React Native applications on tight release schedules |
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Jan 2022 Jan 2023 |
⚪ MERN Stack Developer — Aide Business Solution Dhaka, Bangladesh (Remote)Enterprise ERP & E-Commerce • Engineered and maintained a full-stack e-commerce ERP dashboard, improving operational efficiency across inventory, orders, and reporting workflows • Architected RESTful APIs with TypeScript and Mongoose; managed complex MongoDB schemas for high-traffic enterprise data processing at scale • Crafted highly responsive React + Tailwind CSS applications, translating complex design systems into consistent, intuitive digital products |
Frontend & UI
Backend, APIs & Systems
Databases
Mobile, Cloud & DevOps
📋 Full Technical Skills Reference
| Category | Skills |
|---|---|
| Languages | JavaScript (ES6+), TypeScript, HTML5, CSS3, SQL |
| Frameworks | React.js, Next.js 14, Node.js, NestJS, Express.js, Redux |
| Styling & ORM | Tailwind CSS, Prisma ORM, Mongoose |
| Databases | PostgreSQL, MySQL, MongoDB, Redis, Elasticsearch |
| Mobile & Extensions | React Native, Expo, Chrome Extension (Manifest V3) |
| Cloud & DevOps | AWS, Docker, Vercel, Azure, CI/CD |
| Architecture | REST API Design, Multi-Tenant SaaS, Microservices, WebSockets |
| Tools | Git, GitHub, Postman, Figma, VS Code, Cursor |
| Soft Skills | Agile/Scrum, Tech Leadership, Code Review, Mentorship |
🤖 LeadSync.ai — B2B SaaSMulti-tenant B2B outbound automation platform. Scaled inbox to 1M+ messages/month, cutting p95 latency from 1.4s → 220ms. Multi-channel campaigns (LinkedIn + email), CRM integrations (HubSpot, Salesforce, Pipedrive), zero-downtime Next.js 14 App Router migration.
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💰 TakaMinder — Finance AppOffline-first personal finance tracker for Bengali users. 100% on-device SQLite storage, conflict-aware encrypted Google Drive backup, biometric vault protection. Zero third-party tracking or ads. Live on Google Play Store.
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🛒 Renesa Bazar — E-CommerceFull-scale e-commerce platform — customer storefront, admin console, and NestJS backend. Dynamic PC Builder & Camera Builder configurators, mega-category navigation, high-SKU search with sidebar facets, and inventory-aware merchandising zones.
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Led complete Next.js frontend for an AI-powered resume builder (NYC-based SaaS). ATS-optimised templates, real-time ATS scoring, drag-and-drop resume authoring, voice-led intake, smart job-matching with advanced filtering, and instant cover-letter pairing.
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| Focus | |
|---|---|
| 🤖 | AI-augmented development workflows & LLM API integrations |
| 📱 | Advanced React Native with Expo Router & Reanimated 3 |
| 🏗️ | Distributed systems, message queues, microservices at scale |
| ☁️ | AWS infrastructure, serverless architecture, advanced CI/CD |
| Degree | Institution | Period |
|---|---|---|
| B.Sc. in Mathematics (In Progress) | Thakurgaon Government College, Bangladesh | 2021 – Present |
| Higher Secondary Certificate (Science) | Eco College, Thakurgaon, Bangladesh | 2019 – 2021 |
⚡ "The only constant in technology is change — and I thrive on engineering solutions that outlast trends."
📞 +880 1745-296294 | ✉️ masudhossainmbs129@gmail.com | 🌐 devmasud.tech