You will get legacy Java code modernized to a current, maintainable codebase
Project details
I've spent years pulling old Java systems (Struts, EJB 2, ancient Spring XML configs, Java 6/7) into something a current team can actually work with. I start by getting your code building and tested again if it isn't already, then migrate incrementally: upgrading the JDK, moving to Spring Boot where it makes sense, replacing deprecated libraries, and adding a real test suite so future changes don't break silently. I don't do risky big-bang rewrites unless that's genuinely what the codebase needs. You get a modernization plan before I touch anything, regular check-ins, and a working, documented system at the end rather than a half-finished rewrite that's harder to maintain than what you started with.
Programming Languages
JavaWhat's included
| Service Tiers |
Starter
$149
|
Standard
$450
|
Advanced
$1,200
|
|---|---|---|---|
| Delivery Time | 3 days | 7 days | 14 days |
Number of Revisions | 0 | 0 | 0 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code |
About Younes
Spring Boot Backend Engineer | Secure APIs, OAuth2/Keycloak, Fintech
Casablanca, Morocco - 9:40 pm local time
Most Spring Boot APIs I'm called in to look at fail on the same handful of things: refresh-token rotation misconfigured in Keycloak, IDOR on resource endpoints because authorization is checked at the controller instead of the data layer, JWT validation that trusts the alg header, and multi-tenant queries missing a tenant filter. I find these for a living on both sides — I write the code and I break it.
What I do:
- Spring Boot 3 / Java 21 REST APIs — clean domain modelling, virtual threads where they earn it
- Spring Security: OAuth2, JWT, Keycloak realms, RBAC, multi-tenant isolation
- Security review of an existing Spring codebase — OWASP API Top 10, written report with reproduction steps and patches
- Angular / Next.js front ends when you need one hand on the whole stack
Background: Senior engineer in a bank's digital factory, working on payment and fraud-adjacent microservices. Independent security researcher. Java/Spring core with Docker, Kubernetes, and CI/CD.
Send me your repo or your problem and I'll tell you straight whether I'm the right fit before you spend a dirham.
Steps for completing your project
After purchasing the project, send requirements so Younes can start the project.
Delivery time starts when Younes receives requirements from you.
Younes works on your project following the steps below.
Revisions may occur after the delivery date.
Code audit & modernization plan
I review your codebase, dependencies, and test coverage, then hand you a prioritized modernization roadmap before any code changes begin.