Backend Developer (Java)
Posted on: December 23, 2025 | London-UK (On-Site)
Company Name: 9Nexus.com
Reports to: Engineering Manager / Director of Software Development
Division: Engineering & Technology | Employment Type: Full-Time
Location: London, United Kingdom (On-Site)
Schedule: Standard Business Hours | Experience Level: (06-08) years
Position Summary
We are seeking an exceptional Senior Backend Developer (Java) to join our technology team in London as a Technical Lead. This strategic role combines hands-on technical expertise with leadership responsibilities, focusing on architecting and implementing scalable, high-performance web applications using Java 8+ and modern frameworks within the pharmaceutical domain.
As a Backend Developer and Technical Lead, you'll serve as both a technical architect and team mentor, guiding development initiatives while contributing directly to codebase excellence. This position requires someone who can balance architectural vision with practical implementation, leading by example while elevating the capabilities of the entire development team.
Your expertise in Java development, cloud technologies, and API design will be instrumental in building robust backend systems that power critical pharmaceutical applications. You'll work at the intersection of technology and healthcare, creating solutions that must meet stringent regulatory requirements while delivering exceptional performance and reliability.
This role offers the unique opportunity to shape technical direction, mentor talented developers, and directly impact how pharmaceutical data and processes are managed through innovative software solutions. You'll collaborate closely with Product Owners, stakeholders, and cross-functional teams to translate business requirements into elegant technical solutions that drive operational excellence.
Based onsite in London, you'll work directly with stakeholders and team members, fostering collaboration and ensuring alignment between business objectives and technical implementation. This position is ideal for a seasoned Java developer ready to take the next step in technical leadership while remaining hands-on with code.
Core Responsibilities
Technical Architecture and Leadership
As a Technical Lead, you'll architect, design, and implement scalable, high-performance web applications using Java version 8+ and associated frameworks such as Jersey, Spring Boot, and other enterprise Java technologies. Your architectural decisions will shape how backend systems handle pharmaceutical data, process business logic, and integrate with various enterprise systems.
You'll establish technical standards and best practices that ensure code quality, maintainability, and scalability across all backend development initiatives. This includes defining coding conventions and style guides, establishing architectural patterns and design principles, creating reusable libraries and components, implementing security best practices and compliance measures, and ensuring performance optimization at every layer.
Your hands-on technical leadership involves writing production-quality code that demonstrates best practices, conducting thorough code reviews that mentor and educate, solving complex technical challenges that require deep expertise, evaluating and selecting appropriate technologies and frameworks, and making critical architectural decisions that impact system scalability and performance.
Design patterns, SOLID principles, and clean code architecture guide your development approach. You'll implement microservices architectures where appropriate, design event-driven systems for asynchronous processing, establish robust error handling and logging strategies, implement comprehensive testing strategies including unit, integration, and performance tests, and ensure systems are observable through proper instrumentation and monitoring.
Team Mentorship and Development
Guiding and mentoring a team of backend and frontend developers represents a crucial aspect of your role. You'll foster a culture of continuous learning, knowledge sharing, and technical excellence. Your mentorship extends beyond code reviews to career development, skill building, and professional growth.
You'll promote best practices and code quality through pairing sessions and technical workshops, knowledge sharing presentations and documentation, constructive code review feedback, establishing team coding standards, and celebrating and learning from both successes and failures. Creating an environment where developers feel empowered to experiment, innovate, and grow accelerates team maturity and capability.
Technical guidance you provide includes helping developers understand complex business requirements, breaking down large features into manageable tasks, identifying technical risks and mitigation strategies, teaching debugging and troubleshooting techniques, and demonstrating effective communication with non-technical stakeholders.
Building a high-performing team requires attention to individual growth paths, recognition of contributions, fair distribution of challenging work, and cultivation of psychological safety where team members can ask questions and admit mistakes without fear. Your leadership style encourages initiative, rewards innovation, and maintains high standards while supporting team members in reaching them.
Process Optimization and Agile Collaboration
Collaborating with Product Owners and stakeholders to establish and refine backlog items ensures development efforts align with business priorities. You'll participate actively in requirements gathering, translating business needs into technical user stories with clear acceptance criteria, estimating effort and complexity for development tasks, identifying technical dependencies and sequencing, and providing technical input during sprint planning and backlog refinement.
Your process optimization responsibilities extend to identifying bottlenecks in development workflows, recommending tooling and process improvements, automating repetitive tasks to increase efficiency, establishing CI/CD pipelines for rapid, reliable deployments, and implementing DevOps practices that accelerate delivery while maintaining quality.
Working within Agile methodologies such as Scrum and Kanban, you'll facilitate technical discussions during ceremonies, ensure sprint commitments are realistic and achievable, identify and escalate impediments promptly, contribute to retrospectives with actionable improvement ideas, and balance technical debt with feature development.
Your collaboration with cross-functional teams includes working with frontend developers on API contracts and integration, partnering with DevOps on infrastructure and deployment, coordinating with QA on testing strategies and automation, engaging with security teams on vulnerability remediation, and communicating with business stakeholders on technical feasibility and tradeoffs.
Domain Knowledge and Pharmaceutical Expertise
Developing a strong understanding of the pharmaceutical domain, data models, and regulatory requirements is essential for building compliant, effective solutions. You'll gain deep knowledge of pharmaceutical manufacturing processes, quality management systems, regulatory compliance frameworks (FDA 21 CFR Part 11, EU GMP), data integrity and audit trail requirements, and electronic batch record (EBR) concepts.
Understanding pharmaceutical data models enables you to design efficient database schemas and APIs. You'll model complex relationships between materials, batches, and products, implement genealogy and traceability tracking, design quality event and deviation management structures, create flexible master data models, and ensure data models support regulatory reporting requirements.
Regulatory compliance knowledge guides your technical decisions. You'll implement audit trails that track all system changes, design electronic signature workflows that meet compliance requirements, ensure data integrity through validation and checksums, support system validation activities with proper documentation, and stay current with regulatory guidance affecting software systems in pharmaceutical environments.
Your domain expertise enables meaningful conversations with business stakeholders, allowing you to ask insightful questions that clarify requirements, propose solutions that leverage industry best practices, identify potential compliance issues early in development, and build trust through demonstrated understanding of business challenges.
System Integration and API Development
Designing and implementing integrations with various data sources using modern API technologies represents a core responsibility. You'll develop RESTful APIs following industry best practices, implement web services (SOAP) where required for legacy systems, design GraphQL APIs for flexible data querying, establish API security using OAuth 2.0, JWT, and other standards, and create comprehensive API documentation using tools like Swagger/OpenAPI.
Your API development expertise includes designing intuitive, consistent API contracts, implementing proper HTTP methods and status codes, creating versioning strategies for API evolution, establishing rate limiting and throttling mechanisms, implementing comprehensive error handling and validation, and ensuring APIs are performant and scalable.
Integration patterns you'll implement include synchronous request-response for real-time operations, asynchronous messaging for decoupled systems, batch processing for large data transfers, event-driven architectures for reactive systems, and webhook implementations for external system notifications.
Working with various data sources requires expertise in relational databases (PostgreSQL, Oracle, SQL Server), NoSQL databases (MongoDB, Cassandra) where appropriate, caching layers (Redis, Memcached) for performance, message queues (RabbitMQ, Kafka) for asynchronous processing, and external APIs and third-party services.
Cloud Proficiency and Modern Infrastructure
Demonstrating expertise in cloud-based development and deployment positions you to build scalable, resilient systems. Your cloud proficiency spans major platforms including AWS (EC2, S3, RDS, Lambda, ECS), Azure (App Service, Functions, SQL Database, Kubernetes Service), or Google Cloud Platform depending on organizational preferences.
You'll design cloud-native applications that leverage platform capabilities, implement serverless architectures using Functions/Lambda where appropriate, containerize applications using Docker for consistency, orchestrate containers using Kubernetes for scalability, and implement Infrastructure as Code using Terraform or CloudFormation.
Cloud security practices you'll implement include managing secrets and credentials securely using key vaults, implementing network security with VPCs and security groups, establishing identity and access management (IAM) policies, ensuring encryption at rest and in transit, and conducting regular security assessments and vulnerability scanning.
Cost optimization in cloud environments requires understanding of resource sizing and auto-scaling, leveraging reserved instances and spot instances, implementing proper tagging for cost allocation, monitoring and optimizing storage usage, and establishing cost budgets and alerts.
Required Qualifications and Experience
Professional Experience Requirements
A minimum of 6 to 8 years of hands-on software development experience with Java demonstrates your technical maturity and breadth of expertise. Your background should showcase progressive responsibility from junior developer to senior roles, involvement in complex, enterprise-scale projects, exposure to various architectural patterns and challenges, and proven ability to deliver high-quality solutions.
At least 3 years of experience in a Technical Lead or Senior Developer role ensures you can handle leadership responsibilities. Your leadership experience should include mentoring developers, making architectural decisions, leading technical initiatives, collaborating with stakeholders, and balancing technical excellence with business needs.
Technical Competencies
Deep understanding of Java 8+ features and capabilities forms your technical foundation. You should demonstrate expertise in lambda expressions and functional programming, Stream API for data processing, Optional for null safety, new Date/Time API, CompletableFuture for asynchronous programming, and newer Java versions (11, 17, 21) features.
Proficiency with Java frameworks and technologies is essential:
- Jersey/JAX-RS for RESTful web services
- Spring Framework/Spring Boot for enterprise applications
- Hibernate/JPA for ORM and database access
- JUnit/Mockito/TestNG for testing
- Log4j/SLF4J for logging
Deep understanding of web technologies including HTML, CSS, JavaScript, and TypeScript enables effective collaboration with frontend teams. While this is a backend role, full-stack awareness helps you design better APIs, understand frontend requirements, appreciate performance implications of API design, and contribute to technical discussions across the stack.
Development Tools and Practices
Prior experience working in Agile methodologies such as Scrum and Kanban demonstrates your ability to thrive in iterative development environments. Your Agile experience should include participating in all Scrum ceremonies, working from well-defined user stories, collaborating in cross-functional teams, adapting to changing priorities, and delivering working software incrementally.
Experience with modern development tools ensures efficient delivery:
- Git for version control and collaborative development
- Maven or Gradle for build automation and dependency management
- SonarLint/SonarQube for continuous code quality analysis
- Cobertura/JaCoCo for code coverage measurement
- Azure DevOps for project management, CI/CD, and collaboration
Your CI/CD experience includes implementing automated build pipelines, creating comprehensive test suites that run automatically, establishing deployment automation for various environments, implementing blue-green or canary deployment strategies, and monitoring deployments with rollback capabilities.
Professional Skills and Attributes
Excellent communication skills and prior experience working directly with onsite stakeholders ensure effective collaboration. You should articulate technical concepts to non-technical audiences clearly, present architectural proposals with supporting rationale, facilitate technical discussions and decision-making, document designs and decisions comprehensively, and build strong relationships across organizational boundaries.
Strong problem-solving and analytical skills enable you to tackle complex technical challenges. You should demonstrate systematic debugging and troubleshooting approaches, ability to analyze and optimize performance bottlenecks, capacity to evaluate tradeoffs in technical decisions, skill in breaking down complex problems into manageable pieces, and persistence in finding root causes rather than applying quick fixes.
Technical Environment
Development Stack
- Languages: Java 8+, SQL, JavaScript/TypeScript
- Frameworks: Jersey/JAX-RS, Spring Boot, Hibernate/JPA
- Databases: PostgreSQL, Oracle, SQL Server, MongoDB
- Caching: Redis, Memcached
- Messaging: RabbitMQ, Apache Kafka
- Cloud: AWS, Azure, or Google Cloud Platform
- Containers: Docker, Kubernetes
- Build Tools: Maven, Gradle
- CI/CD: Azure DevOps, Jenkins, GitLab CI
- Monitoring: ELK Stack, Prometheus, Grafana
- Code Quality: SonarQube, Checkstyle, SpotBugs
Development Practices
- Test-Driven Development (TDD)
- Continuous Integration/Continuous Deployment (CI/CD)
- Code reviews and pair programming
- Agile/Scrum methodologies
- DevOps culture and practices
What We Offer
This onsite position in London provides the opportunity to work at the forefront of pharmaceutical software innovation. You'll lead technical initiatives that directly impact healthcare outcomes, mentor talented developers in their career growth, and contribute to systems that ensure product quality and patient safety.
Our commitment to professional development includes technical training and certifications, conference attendance and speaking opportunities, access to learning platforms and resources, mentorship from senior technical leaders, and clear career progression paths to Principal Engineer or Engineering Manager roles.
The pharmaceutical industry's digital transformation creates exciting opportunities to implement cutting-edge technologies, solve complex technical challenges with real-world impact, work with modern development stacks and cloud platforms, and shape the future of healthcare software.
London Location and Work Environment
Based in London, one of Europe's premier technology hubs, you'll enjoy access to thriving tech communities and meetups, world-class cultural and entertainment venues, excellent public transportation and infrastructure, diverse and multicultural environment, and competitive compensation reflecting London market rates.
Our onsite work model facilitates close collaboration with teams and stakeholders, immediate access to subject matter experts, hands-on mentorship and knowledge sharing, strong team cohesion and culture, and rapid problem-solving through face-to-face interaction.
Ready to Lead Backend Development?
If you're an experienced Java developer with passion for technical leadership, cloud technologies, and building systems that make a difference in healthcare, we want to hear from you. Even if you don't check every box in this description, we encourage you to apply. Your unique experience and perspective may be exactly what our team needs.
Join us in London and become part of a team that's transforming pharmaceutical operations through innovative backend solutions. Apply today and lead the development of systems that impact healthcare worldwide.
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