A photo of Mario Campbell, looking at the right

I build products that scale — from architecture to launch.

Mario Campbell

Product-minded engineer with 10+ years shipping SaaS platforms, mobile apps, and backend systems across startups and scale-ups.

Selected Work

Real products, real users, real impact.

Social Platform / Mobile CTO & Lead Engineer

Vanguard

Social platform for martial arts practitioners and academies — training tracking, class booking, geo-based academy discovery, and AI-powered insights. Full monorepo with mobile app (iOS/Android), REST API, and 30+ data models.

Result Alpha with 69+ features shipped, multi-platform deploy
React NativeExpoNestJSPostGISAWS
Healthcare / Mobile + Web Architect & Lead Developer

Healthcare Platform

End-to-end platform for a rejuvenation center: cross-platform mobile app (Expo), admin dashboard with WebAuthn passkey auth, AI-powered features via LangChain, and AWS CloudFront CDN for secure media delivery.

Result Mobile app on TestFlight, AI assistant in production
React NativeExpoNestJSLangChainAWS

I don’t just write code — I ship products.

Over the past decade, I’ve built and led software across SaaS, fintech, crypto, and mobile — from early-stage MVPs to systems serving thousands of users in production.

I work across the full stack: React and Next.js on the frontend, Node.js and Golang on the backend, PostgreSQL and MongoDB for data, and AWS and Docker for infrastructure. I’ve led teams, defined architecture, and shipped products where the decisions actually mattered.

10+ Years building software
Full-Stack Web, mobile, backend, infra
Product-Led I think in outcomes, not tickets

Currently open to consulting, technical leadership, and high-impact collaborations.

Stack

Technologies I use to ship products end-to-end.

Frontend UI, mobile, and client architecture
ReactNext.jsReact NativeTypeScript
Backend APIs, services, and business logic
Node.jsGolangNestJSGraphQL
Data Storage, modeling, and streaming
PostgreSQLMongoDBPrismaKafka
Infra Cloud, containers, and observability
AWSDockerSentryWebSockets

I'm available for select projects, consulting, or leadership roles.

I'm open to collaborating on high-impact projects where I can bring strategy, execution, and code to the table. Let's chat and see how I can help.

Interested in working together? Email me or connect on LinkedIn