Raza Hussain
Senior Full-Stack Developer
Fractional CTO & Lead Engineer · 15 Years
The senior engineer your SaaS needs
I build full SaaS products from scratch, lead technical teams, and take ownership of codebases that need a senior hand. Whether you're starting from zero or scaling a product with 15 years of Rails expertise behind every decision — Upwork Top Rated, 100% Job Success, 25+ Upwork contracts and direct client engagements across US, UK, EU & AU.
Top Rated
100% Job Success · Upwork
US · UK · EU · AU
Long-term contracts
11k+ Followers
LinkedIn · Rails community
Your product's senior engineer — without the full-time hire
SaaS founders hire me when they need a senior technical mind who can own the product — not just execute tickets. I build full platforms from scratch, lead development on growing products, and bring structure to codebases that have outgrown their original design.
15 years in Ruby on Rails, full-stack across React and React Native. I've taken products from idea to launch, scaled apps through growth inflection points, and embedded in teams as the technical lead. I integrate AI features — using OpenAI and Anthropic APIs — into SaaS products where they deliver real value, and I use AI tooling throughout my own development workflow. As an Upwork Top Rated engineer with a 100% Job Success Score, my clients typically stay 6–12+ months.
You get one person who understands your business goals, owns the architecture, writes the code, and communicates clearly — no agency markup, no handoff overhead. Outside client work, I write on technical topics on Medium and have built a Rails developer community of 11k+ on LinkedIn— which means you're hiring someone developers actually trust.
2011
First SaaS product shipped
Started building production Rails apps from day one. Learned early that ownership matters — understanding the business goal behind every technical decision.
2015
Became the technical lead
Started owning full product architecture: database design, API contracts, background jobs, real-time features. The shift from developer to the person founders rely on for decisions.
2019
Top Rated on Upwork · 50+ products
Hit Top Rated status building full SaaS platforms, MVPs, and APIs for founders across the US, UK and AU. Consistent pattern: founders come back for the next product.
2021
Full-stack — web, API and mobile
Added React and React Native to own the complete product surface. One engineer, one context, one communication overhead. Faster delivery, fewer gaps.
Now
Top Rated · Fractional CTO
Top 3% on Upwork. Embedded in SaaS products long-term — part architect, part lead engineer, part technical advisor. Most engagements run 6–12+ months.
Don't take my word for it
Founders and CEOs who hired me, stayed, and came back.
Top Rated
Upwork · 100% Job Success Score
"We hired Raza as senior React developer to help build out our redesigned product using Ruby on Rails. He was instrumental in that effort and worked on the project for almost a year. During that time, he worked in all aspects including front end and back end work. His strength and expertise lies with the back-end work and he ended up becoming the most prolific contributor to our project. If you have Ruby on Rails work or want Custom Application Development Services, Raza can provide the expertise you need to bring your successful project to life."
Colin Bartlett
CEO · StatusGator
"If you are looking to hire React Native developers, Raza is the one! He has a clear understanding of clean code and follows a very efficient work procedure. He consistently delivers high quality results. It is a pleasure to work with Raza, because he understands requirements quickly. He thinks along with the requirements and points out things that might not have been considered — this is very helpful and clearly sets him apart from many of his competitors. He is also an excellent communicator."
Shoaib Iqbal
CEO · DeValley
"First time working with him and got a great experience. He's an expert on Ruby. Delivered before the due date and fixed minor issues really quickly. Understanding requirements very well and had really good discussion and responses. I'll positively hire him again next time. Very recommended for custom application development services!"
Mimi Mongkhonpreedarchai
CEO & Founder · Client
"I hired Mr Raza Hussain for creation of a Docker image for a Ruby on Rails application. Mr Raza is a very senior developer with a vast amount of knowledge. He was able to understand my situation and came up with a solution in no time. I am really thankful for his work as a consultant on Ruby on Rails and would reach out to him in the future."
Agastya T.
Entrepreneur · Ramkee Reddy
Technology stack
15 years of production experience across the full stack. These are the tools I ship with.
Upwork Top Rated
100% Job Success Score · 25+ contracts
Backend
Frontend
Mobile
Data & Infra
AI & LLM
What I build for SaaS founders
Full products from scratch, technical leadership on existing ones, scaling work when growth pushes the limits — all under one roof.
Build from scratch
SaaS Product Development
Starting from zero? I design and build the full product — database schema, Rails backend, React frontend, auth, billing, admin panel, API. You get a production-grade application, not an MVP held together with tape.
- End-to-end Rails + React SaaS
- Multi-tenant architecture
- Stripe billing & subscriptions
- Role-based auth & permissions
- Admin dashboard & analytics
Technical ownership
Fractional CTO / Lead Engineer
You have a product but no senior technical leader. I step in as your lead engineer — own the architecture decisions, review code, manage technical debt, and give you a roadmap you can actually execute.
- Architecture design & review
- Technical roadmap planning
- Code review & quality standards
- Developer team guidance
- Engineering process setup
When traction meets limits
Product Scaling & Growth
Your product is growing and the codebase isn't keeping up. I identify the bottlenecks — slow queries, missing caches, brittle jobs, deployment fear — and systematically remove them so your team can ship faster.
- Performance audit & optimisation
- Database & query tuning
- Redis caching strategies
- Sidekiq background job architecture
- Load testing & capacity planning
iOS & Android with React Native
Mobile App Development
Need a mobile app alongside your web product? I build it in React Native connected to your existing Rails API — one codebase, both platforms, one engineer who understands the full system.
- React Native (Expo & bare workflow)
- Push notifications (FCM / APNs)
- Offline-first with SQLite / MMKV
- In-app purchases & subscriptions
- App Store & Play Store submission
Connect your stack
API & Integrations
Stripe, Twilio, OAuth providers, third-party data feeds, webhooks — I design clean integration layers with proper error handling, retries, and monitoring so external services don't become your weakest point.
- RESTful & GraphQL API design
- Payment gateways (Stripe, PayPal)
- OAuth & SSO authentication
- Webhook architecture & management
- Third-party API integrations
Ship confidently
DevOps & Delivery
CI/CD, Docker, zero-downtime deploys, monitoring, alerting. I set up the infrastructure that makes deployment a non-event — so your team ships on Fridays without a second thought.
- CI/CD pipelines (GitHub Actions)
- Docker containerisation
- Zero-downtime deployments
- Error & performance monitoring
- Security audits & updates
OpenAI · Anthropic · Claude
AI Feature Integration
I integrate LLM APIs into existing SaaS products — content generation, intelligent search, document processing, conversational interfaces. I've shipped Claude API in production and know where AI adds real value vs. where it adds noise.
- OpenAI & Anthropic API integration
- Prompt design & response handling
- AI-powered content generation
- Rails + LLM backend architecture
- Cost & rate-limit management
How an engagement works
Selected Work
Real projects delivered for real clients across web and mobile.
SQL to Active Record
A free tool I built for the Rails community — powered by the Anthropic Claude API. Converts raw SQL into Ruby on Rails Active Record syntax instantly. Built to solve a real problem I kept hitting, now used by Rails devs worldwide.
StatusGator
Hired as senior React developer to help build the redesigned product using Ruby on Rails. Worked on all aspects including front-end and back-end, becoming the most prolific contributor over almost a year.
CryptoZombies
Interactive code school built on blockchain concepts. Developed backend and frontend features for one of the most popular blockchain learning platforms with millions of learners worldwide.
Deltabadger
Automated cryptocurrency DCA (Dollar Cost Averaging) platform. Built robust trading automation, portfolio tracking, and exchange integrations with real-time data processing.
Prograd
EdTech platform connecting students with mentors for career advancement. Built the full learning management system, video sessions, progress tracking, and payment integration.
Outdoor Sports Connection
Full-stack social network for outdoor sports enthusiasts. Delivered both the Rails API backend and the React Native mobile app with feeds, connections, user profiles, and location features.
MeetingKing
Professional meeting management SaaS with agenda creation, action item tracking, and integration with calendar systems. Built Rails backend with real-time collaboration features.
Interested in working together on your next project?
Let's work together →Let's talk about your product
Whether you're building something new, scaling an existing product, or need a senior engineer to take the technical wheel — send me a message on WhatsApp and I'll respond within a few hours. No prepared pitch needed.
Message me directly — fastest route
+92-(312) 426-4919 · Usually responds within a few hours
Upwork
View profile & reviews
Top Rated · 100% Job Success · 25+ contracts
support@razahussain.com
For detailed project briefs
Taking on new SaaS product and fractional CTO engagements now. I work with founders long-term — not one-off jobs. Response time: within a few hours. Covers time zones: US · UK · EU · AU.