You will get a focused React, Next.js, or CSS bug fix
Project details
I will investigate and fix one clearly defined frontend issue in an existing React, Next.js, TypeScript, JavaScript, or CSS codebase.
I focus on small, testable fixes: reproduce the issue, trace the affected component or data flow, change only what is needed, run the available checks, and deliver a concise summary.
This project is not for a full redesign, a new application, or a broad architecture rewrite. If the supplied issue is larger than the selected tier, I will clarify the scope before work begins.
I focus on small, testable fixes: reproduce the issue, trace the affected component or data flow, change only what is needed, run the available checks, and deliver a concise summary.
This project is not for a full redesign, a new application, or a broad architecture rewrite. If the supplied issue is larger than the selected tier, I will clarify the scope before work begins.
Programming Languages
HTML & CSS, JavaScript, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, DesignWhat's included
| Service Tiers |
Starter
$79
|
Standard
$149
|
Advanced
$249
|
|---|---|---|---|
| Delivery Time | 2 days | 3 days | 4 days |
Number of Revisions | 1 | 1 | 2 |
Bug Investigation | |||
Fix Documentation | |||
Detailed Code Comments | - |
Frequently asked questions
About Shota
Senior Backend Engineer | TypeScript, Kotlin & Java APIs
Otsuka, Japan - 12:39 am local time
I bring 10+ years of professional software development experience. My recent work includes data-intensive systems supporting Pokémon Trading Card Game and Pokémon Trading Card Game Pocket. Across two engagements totaling about six and a half years, I built and operated a multi-tenant pharmaceutical EDC system from greenfield delivery through production using Kotlin, Java, TypeScript, and Ktor.
I can help with:
- TypeScript, Kotlin, and Java backend/API bug fixes
- Ktor and Node.js service, validation, authorization, and data-flow issues
- Multi-tenant authorization and data isolation
- GraphQL N+1, SQL query, and Redis/cache performance problems
- React, Next.js, TypeScript, and responsive UI fixes
- AWS/GCP, Terraform, Docker, CI, and development environment issues
For each scoped task, I:
1. Confirm the current and expected behavior
2. Reproduce the issue
3. Make the smallest appropriate change
4. Run the relevant tests, typecheck, API, or browser verification
5. Deliver a concise summary with any remaining risks
My broader experience includes React/Next.js, Rails, MySQL, Redis, AWS/GCP, Terraform, Docker, Kubernetes, CI/E2E, staged refactoring, zero-downtime data and cache migrations, monitoring, and production incident investigation. I work especially well in existing codebases where a safe, testable change matters more than a broad rewrite.
I work exclusively through asynchronous written communication in Upwork Messages. I am not available for phone, video, or other live voice meetings. Written requirements, progress updates, and decisions keep the work precise and easy to audit.
Send the repository or URL, reproduction steps, expected behavior, and sanitized logs or screenshots. I will turn them into a clear first milestone.
Steps for completing your project
After purchasing the project, send requirements so Shota can start the project.
Delivery time starts when Shota receives requirements from you.
Shota works on your project following the steps below.
Revisions may occur after the delivery date.
Confirm and reproduce the issue
I will verify the reported behavior, expected result, affected environments, repository setup, and agreed scope.
Implement the focused fix
I will trace the affected component or data flow and change only what is required for the agreed behavior.