You will get custom API made in Spring
Project details
Production-Ready Spring Boot API with Clean Architecture
Stop building APIs that break under pressure. Most "custom APIs" are quick scripts that turn into maintenance nightmares. I provide a Lead-level architectural foundation designed for stability and long-term scalability.
Leveraging my experience stabilizing high-noise production environments and reducing technical debt, I build APIs focused on Domain Modeling and Reliability.
What is included in this project:
• Clean Domain Layer: Implementation of business logic using the State pattern to prevent invalid data transitions.
• Robust Persistence: PostgreSQL integration with optimized indexing and transactional integrity.
• Hardening: Advanced validation and idempotency to keep your system consistent.
• Observability: Integrated logging and metrics for immediate system health insights.
• Standards: Fully documented REST endpoints (OpenAPI/Swagger) built with Kotlin or Java 17+ and Spring Boot.
I deliver systems based on Senior patterns like Saga or Outbox, ensuring your data is safe even if external services fail. Ideal for startups needing a solid foundation without the overhead of a full-time senior hire.
Stop building APIs that break under pressure. Most "custom APIs" are quick scripts that turn into maintenance nightmares. I provide a Lead-level architectural foundation designed for stability and long-term scalability.
Leveraging my experience stabilizing high-noise production environments and reducing technical debt, I build APIs focused on Domain Modeling and Reliability.
What is included in this project:
• Clean Domain Layer: Implementation of business logic using the State pattern to prevent invalid data transitions.
• Robust Persistence: PostgreSQL integration with optimized indexing and transactional integrity.
• Hardening: Advanced validation and idempotency to keep your system consistent.
• Observability: Integrated logging and metrics for immediate system health insights.
• Standards: Fully documented REST endpoints (OpenAPI/Swagger) built with Kotlin or Java 17+ and Spring Boot.
I deliver systems based on Senior patterns like Saga or Outbox, ensuring your data is safe even if external services fail. Ideal for startups needing a solid foundation without the overhead of a full-time senior hire.
Web Programming Project
API Development, API IntegrationProgramming Languages
HTML & CSS, JavaScript, JavaCoding Expertise
Performance OptimizationWhat's included $800
These options are included with the project scope.
$800
- Delivery Time 60 days
- Number of Revisions 4
- Source Code
Optional add-ons
You can add these on the next page.
Fast 7 Days Delivery
+$400
Additional Revision
+$50About Jonas
Senior Engineer | Kotlin & Spring Boot Specialist | Scalable Systems
Sliedrecht, Netherlands - 9:31 pm local time
Going through several timeouts, breaking the tickets one after another, or the codebase is growing so hard to change that it is getting close to impossible? I help in transforming high-noise situations into stable, predictable, and scalable platforms.
As the Lead Software Engineer of a Dutch logistics tech company, I have a history of successfully taking up entire system architecture responsibilities. I am more than a coder I build dependable systems that enable business expansion.
Results You Can Trust:
- Production Stability: Shrunk critical client issues from ~12 breaking tickets per month to a well-timed and stable release cycle.
- Legacy Modernization: Through updating the Kotlin/Spring backend, rose a long-time waited (5+ years) client project to production.
- Fullstack Ownership: Directed the development line of Kotlin/Spring microservices and React frontends, achieved high data consistency and API reliability.
Technical Competence:
- Backend: Kotlin, Java (17+), Spring Boot, Python/Django.
- Frontend: React, React Native, Next.js.
- Data & Infrastructure: PostgreSQL optimization Docker Kafka, and Event-Driven Architecture.
- Patterns: Domain Modeling, Saga Pattern, Outbox Pattern, and Distributed Systems.
Why Work With Me
What makes me different is that I infuse the "Lead" mindset into each project. I believe clarity in communication, writing maintainable code (clean domain layers), and observability are the essentials. It doesn't matter whether you have a critical performance fix for your PostgreSQL database or need an architectural overhaul of your system.
Available for: Fixed-price projects, architectural consulting, and high-impact backend development.
Steps for completing your project
After purchasing the project, send requirements so Jonas can start the project.
Delivery time starts when Jonas receives requirements from you.
Jonas works on your project following the steps below.
Revisions may occur after the delivery date.
Domain Modeling & Design
Designing the domain layer and state transitions to ensure data consistency and clean architecture.
Database & API Core
Implementing the PostgreSQL schema and core REST endpoints with robust error handling.