Remote Lead Java Developer/Solution Architect

Requirements

Must have:

- Strong hands-on Java development experience building production RESTful APIs, ideally with Spring Boot or a similar framework - Solid working experience with MongoDB, including querying, aggregation pipelines, and integration into Java application layers - Practical experience designing and implementing search solutions using Atlas Search or Lucene-based search within MongoDB - Experience with Client-Side Field Level Encryption (CS-FLE) or equivalent application-layer encryption patterns, with understanding of key management concepts - Experience with Infrastructure as Code, such as Terraform or an equivalent tool, for deploying and managing application infrastructure - Ability to design clean, well-documented RESTful APIs suitable for integration by multiple consuming systems - Experience with load and stress testing tools and approaches for validating API performance under realistic conditions - Proven ability to make architectural decisions, produce design documentation, and communicate technical trade-offs to both engineering and non-technical stakeholders - Experience designing and implementing Attribute-Based Access Control (ABAC) systems, with familiarity in policy-as-code frameworks such as Casbin, OPA, or XACML-based systems - Experience with metadata standards such as DCAT, Dublin Core, or IES - Experience working in UK public sector or defence environments - Familiarity with multi-classification or multi-tenancy access models - Experience with event-driven architectures and asynchronous processing patterns - Understanding of consistency patterns in multi-service architectures, such as saga pattern or eventual consistency - Knowledge of data mesh or federated data architecture concepts - Experience integrating with third-party data storage APIs, such as S3-compatible interfaces - UK resident required - BPSS security clearance required

Responsibilities:

- Lead the design and delivery of the API layer and application logic for a secure metadata catalogue platform - Design the Attribute-Based Access Control model, including policy attributes, enforcement points, and decision logic - Design the RESTful API architecture, including endpoint structure, request and response contracts, and error handling patterns - Map query patterns, access flows, and integration touchpoints with external partner systems - Collaborate with the database consulting engineer on schema design, search strategy, and encryption approach - Contribute to Infrastructure as Code design for deployment - Build a RESTful API layer in Java implementing full catalogue functionality - Deliver CRUD operations for metadata records - Implement advanced search capability leveraging Atlas Search - Enforce ABAC on all API operations so search results and data retrieval are filtered by access attributes - Securely store and retrieve encrypted key material via CS-FLE - Implement unit tests to validate functional correctness - Build automated data load and stress testing harnesses for the combined API and cluster deployment - Perform integration testing against external partner systems or suitable stand-ins - Produce API documentation and integration guides for consuming systems - Support knowledge transfer and handover activities in the final weeks of the engagement

Company:

We are gravity9, and we are seeking a Technical Lead / Solution Architect to help us deliver a secure metadata catalogue platform for a UK public sector client. This is a greenfield build for a 15-week engagement, with half-time commitment for the first four weeks during design and full-time for the remaining 11 weeks during build and integration. The role is mostly remote with periodic onsite attendance. Our delivery team is small and focused, working within a multi-vendor programme and a security-conscious environment, with all work conducted via VPN access to the clients cloud environment. The catalogue integrates with separate data storage and encryption services delivered by other organisations, and we will need someone comfortable collaborating across these boundaries while supporting knowledge transfer, API documentation, and integration guides at the end of the engagement.