You will get an ASP.NET Core API or SQL bug diagnosed and fixed in 48 hours
Project details
Get one focused ASP.NET Core, REST API, or SQL problem diagnosed and—on Standard or Advanced—fixed within 48 hours after complete intake. Starter delivers root cause, evidence, and a next step for one reproducible issue. Standard delivers one reviewable patch plus focused validation. Advanced adds priority handling, a handoff call, and two revisions.
I am a senior full-stack .NET engineer with 8+ years of experience across APIs, integrations, SQL-backed workflows, Angular and React, Azure/AWS, Git, and CI/CD. I work from a minimal sample or code archive, keep scope bounded, and do not require production credentials. Delivery includes findings or patch, validation notes, changed files, assumptions, and a clear next step. English: Fluent. Availability: up to 20 hours per week.
I am a senior full-stack .NET engineer with 8+ years of experience across APIs, integrations, SQL-backed workflows, Angular and React, Azure/AWS, Git, and CI/CD. I work from a minimal sample or code archive, keep scope bounded, and do not require production credentials. Delivery includes findings or patch, validation notes, changed files, assumptions, and a clear next step. English: Fluent. Availability: up to 20 hours per week.
Programming Languages
ASP.NET, C#What's included
| Service Tiers |
Starter
$99
|
Standard
$249
|
Advanced
$399
|
|---|---|---|---|
| Delivery Time | 2 days | 2 days | 2 days |
Number of Revisions | 1 | 1 | 2 |
Number of Pages | 0 | 0 | 0 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code |
Frequently asked questions
About Leonardo
Senior Full-Stack .NET Engineer | APIs, Angular & React
Buenos Aires, Argentina - 8:02 pm local time
I help businesses build and improve secure, maintainable full-stack applications using C#/.NET, ASP.NET Core, REST APIs, Angular, React, TypeScript, PostgreSQL, SQL Server, Azure, AWS, Git, and CI/CD. I also build RAG solutions with Microsoft Semantic Kernel, LLM and embedding integrations, vector search, and document ingestion pipelines for custom knowledge bases.
I can help with:
• REST API development and third-party integrations
• RAG chatbots and semantic search over business documents
• Document ingestion, chunking, indexing, and update workflows
• Legacy .NET modernization and migrations
• New features for existing web applications
• PostgreSQL and SQL Server development
• Production bug fixing, performance, and reliability improvements
• Azure/AWS deployments and practical Git/CI/CD workflows
I bring 8+ years of experience delivering business-critical software across enterprise operations, financial workflows, maritime tracking, and subscription platforms. I communicate clearly, work comfortably from written requirements, and prefer small, reviewable releases with straightforward testing and rollback plans.
Available for focused, asynchronous freelance projects for up to 20 hours per week.
Steps for completing your project
After purchasing the project, send requirements so Leonardo can start the project.
Delivery time starts when Leonardo receives requirements from you.
Leonardo works on your project following the steps below.
Revisions may occur after the delivery date.
Confirm scope and reproduce
I verify the issue is reproducible, focused, and suitable for the selected package before work begins.
Diagnose or fix
Starter receives cause and evidence. Standard and Advanced receive one focused reviewable patch.