Álvaro
Data Scientist
“In a climate this uncertain, Shakers gives you a layer of reassurance and confidence. What I like most, without a doubt, is the flexibility and getting to work on top-tier projects.”
Join ShakersShakers for expert talent
Work as a Java Developer by project
Projects where the ecosystem is you: which API gets versioned, which service leaves the monolith and who decides what goes to Kafka. Shakers connects you with teams keeping banking, insurance and government running in production.
What gets read about the role is eternal roadmaps and the yearly debate on whether Java died, again. Neither tells you how to start sustaining real systems by project: what gets extracted from an insurer's monolith, how an API consumed by half a company gets versioned. Here is that.
- Higher-paying projects
- More continuity between projects
- Greater recognition for your experience
+3,000
Tech projects published on Shakers
+90
Tech, Product and Data specialisms are part of Shakers
6 months
Average length of a project with Shakers
4.7/5
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Amelia
AI Agent Developer
“I have been building AI agents for years. Thanks to Shakers I stopped chasing clients and started genuinely choosing which projects I wanted to work on. I work with some of the best companies in Europe, at my own rate, and I focus on what I am good at and what I love: building.”
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Luz
Backend Developer & Data Engineer
“Shakers adds a lot of value because it connects you with sharper projects, already filtered and better defined. It saves you a big part of the upfront work of understanding the client, quoting and weighing up whether it is worth it, and that means that as a contractor you can go far more directly to the opportunities that genuinely fit you.”
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Rubén
Software Developer
“Life as a contractor has a lot going on and it is not always easy. We like to focus on what we are good at, but you also have to manage clients, invoicing and go looking for work. For me, Shakers has been key because it does that prospecting for me, it gives the client confidence from the very first moment, and it lets us be part of a community with real enthusiasm.”
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Alejandro
AI Developer
“Shakers was key to getting my company off the ground: it gave me the flexibility to keep contracting while I built my next chapter. Without Shakers, I would have had to raise funding or push the project back.”
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Toño
Product Designer
“With Shakers I have landed recurring projects that give me peace of mind and room to grow professionally. It is not just about reaching quality clients: it is feeling that you have a network behind you, one that connects you with real opportunities and helps you move forward as a freelancer.”
Join ShakersThe decisions a Java Developer owns every week
A Java Developer builds and sustains the systems that run in production in banking, insurance and government: services on the JVM with Spring Boot, REST APIs with contracts that cannot break, data in SQL or in the company Oracle and messaging with Kafka. Their craft is the whole ecosystem, from the framework to the LTS version, and their proof of level is sustained production: versioning without breaking, migrating piece by piece and deciding what leaves the monolith and what stays.
You decide which endpoint goes into the next API version and which contract gets frozen, which logic leaves the monolith towards a microservice and what stays in the Oracle that already works. You also decide what the system refuses: a deployment without tests does not go out. The business is the client's; the ecosystem judgement, yours.
Java 21Spring BootMicroservicesREST APIsKafkaSQLOracleJPA/HibernateMavenDockerKubernetesCI/CDJenkinsJWT/OAuth2AngularKotlin
JVMSpring BootMicroservicesKafkaREST APIsLiving legacy
Free to join, no hidden fees
How Shakers works for talent
Create your profile
Tell us who you are, what you can do, the projects you want to work on and what your availability and rate are.
Get your certification
We certify your experience and your use of AI so companies understand and trust what you bring.
Match with projects
We connect you with well-paid projects that fit your expertise and your preferences.
Software Engineering projects that live up to your expectations
Work on real projects, with teams that need your expertise, without wasting time looking for opportunities.
Projects that fit you
Work with companies that need your stack and experience to take their projects to production.
Opportunities that come to you
Our AI matching connects your profile with the projects that fit your preferences.
You build. Shakers handles the rest
Set your own terms based on your seniority. We manage contracts, payments and paperwork.
What you run as a Java Developer on a Shakers project
The project arrives with the system
The brief arrives with a production system behind it: banking, insurance or government. The conversation starts with the concrete pain, not with technologies.
APIs that break nobody
Versioned endpoints with their contracts, tests and documented deployment. Whoever consumes the API does not even notice you renewed the service underneath.
What leaves the monolith
You decide which logic gets extracted to a microservice, what goes to Kafka and what stays in the Oracle that works: by risk and by value, never by fashion.
Production, told
Having sustained real systems and knowing how to tell it: your last serious incident, how you reverted it and what you instrumented so it would not repeat.
The whole dialect
Spring Boot on the client's LTS, JPA or SQL depending on the house, Maven in the build and CI/CD at deployment. The whole ecosystem, not just the language.
Where your brief ends
You build and sustain the java; the cloud and the cluster have their own page. If the project asks for architecture or interface, it gets said at kickoff.
Frequently asked questions
Any other questions? Write to us and we will reply.
Is AI replacing Java developers?
No: 1,157 ads in Spain ask for Spring Boot and 3,384 carry java in their skills (Shakers market analysis, n=31,162, September 2026). AI absorbs boilerplate; what stays paid is production judgement.
Is Java outdated in 2026?
No: Java 21 is the current LTS and senior ads ask for microservices, Kafka and Kubernetes on the JVM. The ecosystem renews itself; it does not switch off.
Is there still demand for Java Developers in Spain?
Yes, and concentrated on the enterprise side: banking, insurance and government keep systems that never switch off. Shakers analysis sees 3,384 ads with java among their skills.
How much do you earn as a Java Developer by project?
The market and the scope set it: which system you keep running, with which stack and how much maintenance comes in. At Shakers you agree the budget per project before accepting.
Does the Oracle certification matter to join Shakers?
It gets valued, but it does not decide: Shakers certification proves real production work, not an exam. Oracle's seals the language; ours seals the craft of sustaining the system.
How do you join Shakers as a Java Developer?
You create your profile, pass the certification process and enter the collective: only 4 percent make it. Then you choose which Java projects you take on.
The daily shape of the craft
The API that gets versioned without breaking whoever consumes it, the service leaving the monolith this sprint, the Kafka queue holding December's peak. A system real people stand on.
The tools are the craft
1,157 active tech job ads in Spain ask for Spring Boot (Shakers market analysis, n=31,162, September 2026). The stack of the ads: Spring Boot almost always, Kafka in senior roles, SQL and Oracle in enterprise, Kubernetes to deploy.
How people get here
Two doors: the junior who grew in a consultancy or a bank and knows the legacy, and the backend developer from another language who crossed to the JVM. Kotlin is the sister frontier: 629 ads in Spain mention it.
What this role is not
If the brief is the interface with Angular or React, the full stack page sets the cut; if it is the pipeline or the cluster, DevOps. The border gets declared at kickoff.
The roles a Java project crosses
Five roles cross your path as you sustain a Java system in production: from the generic backend to the cluster where the microservice runs.
Backend Developer
Java is a backend with a surname: when the brief names no language or ecosystem, the generic filter is theirs; the java stem and Spring are yours.
Full Stack Developer
The market posts the mixed profile (Java with Angular or React) as a job ad, not a role: the interface of the brief gets shared with this page when it comes up.
Test Automation Engineer
Tests what you sustain: regression of APIs and services in production, with suites running in the same pipeline as your deployment.
DevOps Engineer
Your modern jar deploys in a container: their CI/CD publishes what you deliver and the daily border gets agreed in the same repository.
Kubernetes Engineer
Today's Java runs on Kubernetes: a good part of Spring Boot ads already requires it in senior roles. If the brief is the cluster, the project is theirs.
Boundaries between these roles are agreed per project: the job title doesn't set them.
Take the next step with Shakers
Want to keep systems that already run?
Pass Shakers certification and choose which Java production systems you work on.
