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You will get Bugs Fix & Performance Improvement in Web App

Zulqarnain N.Status: Offline
Zulqarnain N. Zulqarnain N.
4.8
Top Rated
Preview image

Let a pro handle the details

Buy Web Programming Bug Fixes services from Zulqarnain, priced and ready to go.
Zulqarnain N.Status: Offline
Zulqarnain N. Zulqarnain N.
4.8
Top Rated
Preview image

Let a pro handle the details

Buy Web Programming Bug Fixes services from Zulqarnain, priced and ready to go.

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. 🚀
Programming Languages
JavaScript, Ruby/Ruby on Rails, TypeScript
Coding Expertise
Cross Browser & Device Compatibility, Performance Optimization, Security
What's included
Service Tiers Starter
$80
Standard
$120
Advanced
$400
Delivery Time 2 days 5 days 10 days
Number of Revisions
123
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)
+$50

Frequently asked questions

4.8
22 reviews
95% Complete
(21)
1% Complete
(0)
1% Complete
(0)
1% Complete
(0)
5% Complete
(1)

CN

Chris N.
5.00
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.
5.00
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.
5.00
Mar 30, 2026
React Native Mobile App Developer

JB

Justin B.
5.00
Jan 14, 2026
Rafl Shopify App Development Sweepstakes

AA

Abdulmohsen A.
5.00
Dec 9, 2025
Node.js and React.js Developer for SaaS Application Highly recommended, Smart and professional
Zulqarnain N.Status: Offline

About Zulqarnain

Zulqarnain N.Status: Offline
AI Engineer | LLM Features in Production Apps | Node, Next.js, Python
100% Job Success
4.8  (22 reviews)
Raiwind, Pakistan - 10:03 pm local time
Most AI features never make it past the demo. I build the ones that ship, LLM systems inside real production applications, with the backend, auth, data model, and cost controls to survive actual users.

12 years engineering, 5,160 hours on Upwork, 34 contracts, 100% Job Success. MPhil in Data Science, PUCIT.

WHAT I BUILD
- RAG pipelines over real company data, chunking, embeddings, retrieval quality, evaluation
- Multi-agent and workflow automation systems with proper error handling and retries
- OpenAI and Anthropic integrations wired into product surfaces, not bolted on
- The application around it: Node.js, Next.js, TypeScript, Python, PostgreSQL
- Token and latency cost control, most AI features die on unit economics, not capability

ALSO STRONG IN
Ruby on Rails modernization and rescue work, multi-tenant SaaS architecture, performance and database optimization.

HOW I WORK
I ask what the product needs to do six months from now before I write anything. You get working code in the first week, not a discovery phase. I'm reachable within four hours during US business time, and I say when something is a bad idea.

Available 35+ hrs/week, open to contract-to-hire.

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.

Review the work, release payment, and leave feedback to Zulqarnain.