You will get Bugs Fix & Performance Improvement in Web App
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Top Rated
Project details
I fix bugs and improve performance in Rails/Node/React web apps so your product becomes stable, fast, and reliable.
This catalog is ideal if your app has broken features, slow pages, API issues, or database bottlenecks. I’ll reproduce problems, identify the real root cause, apply clean fixes, optimize performance, and share a clear summary of what changed so your team can confidently move forward.
You’ll get: faster load times, fewer errors, cleaner code, and a smoother experience for users. 🚀
This catalog is ideal if your app has broken features, slow pages, API issues, or database bottlenecks. I’ll reproduce problems, identify the real root cause, apply clean fixes, optimize performance, and share a clear summary of what changed so your team can confidently move forward.
You’ll get: faster load times, fewer errors, cleaner code, and a smoother experience for users. 🚀
Programming Languages
JavaScript, Ruby/Ruby on Rails, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$80
|
Standard
$120
|
Advanced
$400
|
|---|---|---|---|
| Delivery Time | 2 days | 5 days | 10 days |
Number of Revisions | 1 | 2 | 3 |
Bug Investigation | |||
Fix Documentation | - | ||
Detailed Code Comments | - | - |
Optional add-ons
You can add these on the next page.
Additional Revision
+$30
Fix Documentation
(+ 2 Days)
+$50Frequently asked questions
22 reviews
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CN
Chris N.
Jun 15, 2026
Fullstack Developer with Strong Backend talent for Ruby-on-Rails Project
Z and his team, Huzaifa especially, will remain important partners to us for the long run due to the quality of support and expertise they brought to us for 12 months of working together. They are true partners
KW
Ken W.
Jun 15, 2026
Frontend Developer (React + shadcn/ui + Tailwind v4) — Fitness SaaS
Although our collaboration was short-term, working with Zulqarnain was an absolute pleasure. His communication skills and professional approach are outstanding. Beyond his work ethic, his great personality makes him a joy to work with. I highly recommend him to other clients and would definitely love to partner with him again on future projects.
BW
Brent W.
Mar 30, 2026
React Native Mobile App Developer
JB
Justin B.
Jan 14, 2026
Rafl Shopify App Development Sweepstakes
AA
Abdulmohsen A.
Dec 9, 2025
Node.js and React.js Developer for SaaS Application
Highly recommended, Smart and professional
About Zulqarnain
AI SaaS Engineer | React, Next.js, Node.js, Rails | Stabilize & Scale
100%
Job Success
Raiwind, Pakistan - 12:58 pm local time
With 12+ years of experience building, scaling, and optimizing SaaS products, I help startups and growing companies transform ideas into high-performance, revenue-generating applications. From MVP development to enterprise-scale platforms, I bring a product-focused engineering approach that prioritizes performance, reliability, maintainability, and business outcomes.
𝐂𝐨𝐫𝐞 𝐄𝐱𝐩𝐞𝐫𝐭𝐢𝐬𝐞
✓ AI-Powered SaaS Applications & LLM Integrations
✓ React.js, Next.js, TypeScript & Modern JavaScript
✓ Node.js, Express.js & Backend Architecture
✓ Ruby on Rails Development & Modernization
✓ REST APIs, GraphQL & Third-Party Integrations
✓ PostgreSQL, MySQL, MongoDB & Database Optimization
✓ SaaS Architecture, Multi-Tenant Systems & Subscription Platforms
✓ Authentication, Authorization & Security Best Practices
✓ Performance Optimization, Debugging & System Stabilization
✓ Cloud Infrastructure, CI/CD & DevOps Workflows
✓ Technical Leadership, Code Reviews & Team Mentorship
✓ Product Development from Concept to Production
𝐖𝐡𝐚𝐭 𝐈 𝐃𝐞𝐥𝐢𝐯𝐞𝐫
• Scalable SaaS platforms built for long-term growth
• Clean, maintainable, and production-ready codebases
• High-performance web applications with exceptional user experiences
• Robust backend systems capable of handling increasing traffic and demand
• AI-driven features that create measurable business value
• Reliable deployment pipelines and streamlined development workflows
• Technical solutions aligned with product and business objectives
𝐈𝐧𝐝𝐮𝐬𝐭𝐫𝐢𝐞𝐬 & 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐬
• AI & Automation Platforms
• B2B and B2C SaaS Products
• Marketplaces & Subscription-Based Applications
• FinTech & Business Operations Tools
• CRM, ERP & Internal Business Platforms
• Analytics & Data-Driven Applications
• Startup MVPs & Enterprise Software Solutions
𝐖𝐡𝐲 𝐂𝐥𝐢𝐞𝐧𝐭𝐬 𝐖𝐨𝐫𝐤 𝐖𝐢𝐭𝐡 𝐌𝐞
• 12+ years of professional software engineering experience
• Strong full-stack expertise across frontend, backend, and cloud infrastructure
• Proven ability to stabilize underperforming applications and scale growing products
• Deep understanding of SaaS business models and product development lifecycles
• Clear communication, ownership mindset, and results-driven execution
Whether you need to launch a new SaaS product, modernize an existing platform, integrate AI capabilities, or resolve critical performance and scalability challenges, I bring the technical expertise and strategic thinking required to move your product forward with confidence.
𝐊𝐞𝐲𝐰𝐨𝐫𝐝𝐬:
AI SaaS, SaaS Development, SaaS Engineer, Full Stack Developer, Full Stack Engineer, React.js, Next.js, Node.js, Ruby on Rails, Rails, TypeScript, JavaScript, MERN Stack, Web Development, Frontend Development, Backend Development, API Development, REST API, GraphQL, PostgreSQL, MySQL, MongoDB, Database Design, Database Optimization, Cloud Computing, AWS, Vercel, Docker, CI/CD, DevOps, Microservices, System Architecture, Software Architecture, Enterprise Applications, SaaS Architecture, Multi Tenant SaaS, AI Integration, OpenAI, Claude AI, Anthropic, LLM Integration, AI Automation, Generative AI, Chatbot Development, Workflow Automation, Performance Optimization, Application Scaling, Scalability, System Stabilization, Bug Fixing, Code Refactoring, Technical Leadership, Team Lead, Product Engineering, MVP Development, Startup Development, Agile Development, Software Engineering, Web Applications, Platform Engineering, Digital Transformation
Steps for completing your project
After purchasing the project, send requirements so Zulqarnain can start the project.
Delivery time starts when Zulqarnain receives requirements from you.
Zulqarnain works on your project following the steps below.
Revisions may occur after the delivery date.
Quick audit & reproduction
I reproduce issues, review logs, and confirm scope + priorities.
Fix bugs (root-cause first)
Fix issues with clean patches and avoid “band-aid” solutions.