reimplement existing API with Java Spring-Boot 4 signal-chat

We look for Java Spring-Boog and Core-Java senior expert developer

Your job will be to re-implement this api in java / spring-boot
https://github.com/bbernhard/signal-cli-rest-api/tree/master

Mandatory!!!!
You have to have a installed the docker environment on you PC/Laptop and You document EACH step step to make the https://github.com/bbernhard/signal-cli-rest-api/tree/master up and running
along with
a docker compose environment to make the new spring-boot api running with it.

Milestones
MS1:
suggest if an openAPI definition would reduce your workload, since REST server and client can be generated

MS2:
reImplement as spring boot service the endpoints documented
here: https://github.com/bbernhard/signal-cli-rest-api/blob/master/doc/EXAMPLES.md
and: https://bbernhard.github.io/signal-cli-rest-api/

MS3:
provide a docker compose incl. all steps to make your code available in a container


Implementations:
- best practices with openAPI
- best practices with spring boot

NO UI for now required!
NO database required!
No REST endpoint exposing for the above named methods required! (only consuming the apis in the given links)

Your background is:
- multiple years of experience with Java
- multiple years of experience with REST APIs

If you are a good fit, you are open to get more tasks about implementing solutions fully on your own (e.g. with your team)

Budget?
will not be disclosed, place your best bid to get considered

What is next?
We will share you a NDA and afterwards a paid test task.

Payment?
- you estimate in a WBS (optimistic, expected, pessimistic, where optimistic < expected < pessimistic) after getting the task
- we discuss about clearances and effort
- we mutually agree to effort
- we assign you the task after mutually agreed
- you implement, test and deliver
- you provide also unit /integration tests to ensure code is always working
- you document each required step to make interaction of systems to work
- we test on our premise (you maybe help to fix issues)
- we pay
(basically the rules of freelancer)

Closed book vs open book?
We work only on open book.
Closed book means you are unwilling to define a WBS for the work and you add only a price tag to the task.
We are sorry we will not hire you in such a case!

Deliveries?
- in our on premise git (access will be granted to you)
- full sources
- mutliple samples of body and responses of the api in test/resources which will be used as unit tests
- maven
- libs, need prior confirm and we prefer to use mostly latest stable versions
- JDK 17 (mostly LTS)
- your api code working on our end
- provided or fully documented steps to start the docker container