You will get a diagnosed and fixed issue in your web application
Project details
Is your web application affected by a blocking bug, unexpected behavior, failed request, broken feature, or production issue?
I will investigate the problem, identify the most likely root cause, and implement a fix when the issue falls within the agreed scope.
As a senior full-stack developer, I approach debugging methodically. I review the application behavior, logs, code, configuration, and relevant infrastructure to understand what is failing and why.
This project includes:
• Initial review of the reported issue
• Reproduction of the bug when possible
• Application log analysis
• Code and configuration investigation
• Root-cause identification
• Bug fix when technically possible within scope
• Functional testing after the correction
• Clear explanation of the problem and solution
• Recommendations to prevent similar issues
You will receive either a corrected application or a clear technical diagnosis with recommended next steps when the issue requires broader work.
I will investigate the problem, identify the most likely root cause, and implement a fix when the issue falls within the agreed scope.
As a senior full-stack developer, I approach debugging methodically. I review the application behavior, logs, code, configuration, and relevant infrastructure to understand what is failing and why.
This project includes:
• Initial review of the reported issue
• Reproduction of the bug when possible
• Application log analysis
• Code and configuration investigation
• Root-cause identification
• Bug fix when technically possible within scope
• Functional testing after the correction
• Clear explanation of the problem and solution
• Recommendations to prevent similar issues
You will receive either a corrected application or a clear technical diagnosis with recommended next steps when the issue requires broader work.
Programming Languages
HTML & CSS, JavaScript, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$275
|
Standard
$600
|
Advanced
$950
|
|---|---|---|---|
| Delivery Time | 3 days | 6 days | 8 days |
Number of Revisions | 1 | 1 | 2 |
Bug Investigation | |||
Fix Documentation | |||
Detailed Code Comments |
Frequently asked questions
About William
Senior Full Stack Developer | MVP, SaaS, AI
Paris, France - 10:44 am local time
With 10 years of experience in front-end and back-end development, I help startups, entrepreneurs, and small to mid-sized businesses turn ideas into functional, fast, and scalable web applications.
Whether you need a SaaS MVP, a custom dashboard, a business application, or a complex third-party integration, I focus on delivering practical solutions with a clear scope, predictable progress, and maintainable code.
## What I Bring to Your Project
- End-to-end full-stack development: React, Vue.js, Node.js, Ruby on Rails, PostgreSQL, MySQL, MongoDB, Docker, and Kubernetes
- Product-focused experience: I have launched several SaaS products of my own, including a data platform, a link-in-bio tool, and an online directory. I understand product and business challenges, not just technical implementation.
- Fast, iterative delivery: I work in short development cycles and provide intermediate versions so you can review progress and validate decisions early.
- Clear written communication: Project updates, technical decisions, tickets, and documentation are handled in writing for clarity and traceability.
- Maintainable solutions: I prioritize clean architecture, structured code, appropriate technology choices, and documentation that makes future development easier.
## Typical Projects
- Conversion-focused landing pages with custom admin panels
- SaaS MVPs with authentication, dashboards, subscriptions, payments, and APIs
- Custom business applications and internal tools
- Third-party API integrations and data-processing systems
- Refactoring and modernization of existing applications
- Backend and API development
- Deployment, infrastructure configuration, and DevOps support
I am available for fixed-scope projects, ongoing freelance work, and long-term technical partnerships.
Send me a message with an overview of your project, current challenges, and expected outcome, and I will help you identify the best way forward.
Steps for completing your project
After purchasing the project, send requirements so William can start the project.
Delivery time starts when William receives requirements from you.
William works on your project following the steps below.
Revisions may occur after the delivery date.
Issue Review
I review the symptoms, error messages, affected environment, expected behavior, and recent changes.
Access and Reproduction
I access the relevant codebase and environment and attempt to reproduce the problem. Reproducing the issue is often essential for identifying the root cause and validating the fix.