Logo of Huzzle

Senior Developer Java

Applications are closed

  • Job
    Senior Level
  • Software Engineering
  • London


  • Technical Expertise as a Senior Backend Developer.
  • Experience with Java 8/11,17+, Java Streams, Java Collections, Spring Boot, Hibernate, Groovy, SQL, Artifactory.
  • Experience with Git, Jenkins and command line tools for helper tools development, use package managers (maven, pip), debugging and unit testing.
  • Experience with version control such as Git and GitHub to manage codebase changes and collaborate effectively with other team members across global markets.
  • Experience with the Atlassian suite of tools - Jira, Bitbucket, Confluence, etc.
  • Knowledge of common development best practices (e.g., TDD, agile).
  • Experience with modern CI/CD workflows.
  • Multi-project commercial experience with relevant tools such as >Java11 (OpenJDK), Docker, Kubernetes, Maven, Jenkins, NVM, RESTful APIs, ActiveMQ or similar.
  • The ability to communicate effectively and proactively with team members, stakeholders, and clients to understand requirements and provide updates on project progress.
  • You May Have:
  • Experience with AWS Lambda, EC2, ECS, EKS, ECR, SQS, REST, EKS, ActiveMQ, Docker, Kubernetes, NodeJS, Maven, Jenkins, OSGi, PostgreSQL, MySQL.
  • Experience working in an agency environment.


  • Be responsible for various aspects of designing, developing, and maintaining the server-side of web applications and APIs utilising Java / Spring Boot.
  • Collaborate with cross-functional teams, including Developers, Tech Leads, Technical Architects and Project Managers to design scalable and efficient backend architectures.
  • Evaluate and select appropriate technologies, frameworks, and tools for backend development based on the project requirements.
  • Review code written by other developers and provide constructive feedback to ensure code quality and adherence to best practices. Mentor and guide junior developers on coding standards and best practices.
  • Identify and address performance bottlenecks in the backend code, databases, and infrastructure to improve application speed and efficiency.
  • Implement security measures to protect data and ensure compliance with industry standards and best practices such as GDPR.
  • Develop and execute unit tests, integration tests, and automated test scripts to ensure the reliability and stability of backend services. Participate in the deployment and monitoring of applications with the DevOps team.
  • Design and optimise databases, write efficient complex queries, and ensure data integrity and consistency (SQL).
  • Create and maintain APIs (Application Programming Interfaces) for frontend clients, mobile apps, and external services.
  • Create and maintain technical documentation for the applications, APIs, and infrastructure.
  • Investigate and resolve issues and bugs reported by users or identified through testing and monitoring.


What are the main responsibilities of a Senior Developer Java?

The main responsibilities of a Senior Developer Java include providing technical expertise in requirement assessments, planning technical implementations, following development best practices, collaborating with other team members, designing and developing applications, ensuring the involvement of Quality Assurance and DevOps teams, and mentoring team members in Java/J2EE technologies.

What skills are required for a Senior Developer Java role?

Skills required for a Senior Developer Java role include expertise in Java programming, knowledge of J2EE technologies, experience in software development best practices, the ability to collaborate with team members and stakeholders, proficiency in designing and developing applications, and the capability to mentor and support team members.

What level of experience is needed for a Senior Developer Java position?

A Senior Developer Java position typically requires several years of experience in software development, specifically in Java programming and J2EE technologies. Candidates should have a proven track record of successfully delivering applications, collaborating with team members, and mentoring junior developers.

What is the importance of collaboration in a Senior Developer Java role?

Collaboration is crucial in a Senior Developer Java role as it involves working closely with Tech Leads, Architects, Directors, Quality Assurance, and DevOps team members to design, develop, and deliver applications. By collaborating effectively, the Senior Developer can ensure the successful completion of projects and the delivery of high-quality, maintainable code.

We design experiences for brands we love. Anywhere we go, digital is our home. Canada + The World, Since ’96.

Marketing & Advertising
Founded Year

Mission & Purpose

Critical Mass is a team of 1,500 inspired folks based in 12 offices around the world, providing full-service digital capabilities for the greatest brands on Earth. Our secret sauce is our uncompromising design standards, our relentless focus on customers, and an ability to put powerful new technologies to work for our clients. We work with the best—Apple, Nike, Diageo, Airbnb, BMW, BNY Mellon, Johnson & Johnson, and many more—brands who strive for connected digital ecosystems and unparalleled experiences. We help them get there by gaining deep insight into their consumers and orchestrating data, AI, design, media, and tech stacks around human stories. We’re a global agency founded in Canada, but digital is our home. If you know us, then you know we’re a special, quirky place that attracts big talent and tiny egos. (We actually give out a “so f-n nice” award—lots of them). But just because we’re friendly doesn’t mean we’re not a force to be reckoned with. We’re driven. Relentless. And we live our values. We’re Critical Mass, but our friends call us CM. Please call us CM!