Lead Java Developer/Solution Architect (Java/MongoDB)

Location: UK resident; work is delivered from the UK by UK-onshore staff. Predominantly remote with periodic onsite attendance and occasional travel to client sites in London, Manchester and Leeds.

Company

hirify.global delivers Java engineering and architecture engagements for large-scale UK central government modernisation programmes.

What you will do

• Produce high- and low-level designs, security and data architectures, and architecture decision records for formal client governance.
• Design and implement MongoDB document models, aggregation pipelines, indexing and sharding strategies across Atlas and Enterprise Advanced.
• Build production Java services and OpenAPI-documented REST APIs using Spring Boot or an equivalent framework.
• Develop CDC and streaming pipelines, transformation frameworks, checkpointed batch extract workers, migration tooling and reconciliation harnesses at terabyte scale.
• Implement access control, encryption, tamper-evident audit trails and observability within application and data layers.
• Collaborate with client engineers and other suppliers, run workshops and demonstrations, produce operational documentation, and support knowledge transfer.

Requirements

• Strong hands-on Java experience building and operating production services and RESTful APIs with Spring Boot or an equivalent framework.
• Solid MongoDB experience covering document modelling, querying, aggregation pipelines, indexing, and integration with Java application layers; experience with Atlas and/or Enterprise Advanced.
• Demonstrable experience with data-intensive pipelines, migrations or integrations at meaningful scale, including throughput, ordering, idempotency and failure recovery.
• Experience designing clean, well-documented REST interfaces for multiple consuming systems.
• Automated testing discipline and practical load and stress testing against realistic volumes.
• Experience with Terraform or equivalent infrastructure as code, containerised Kubernetes deployment, and AWS or a comparable cloud.
• Ability to write clear design documentation and participate effectively in client design authorities or architecture reviews.
• UK resident and either holding current UK SC clearance or clearly eligible to obtain it.
• For architect-level roles: proven design authority on a delivery of comparable size and sensitivity while remaining hands-on enough to prototype, pair and review code; experience working in multi-vendor or multi-supplier programmes.

Nice to have

• UK public sector experience or experience in another regulated and security-conscious environment.
• Kafka, Debezium, change-data-capture tooling and stream processing.
• Legacy modernisation patterns, including strangler fig, operational data layers, dual running and phased cutover.
• Domain-driven design, bounded-context analysis and monolith decomposition.
• Attribute-based access control, policy-as-code, OPA, Casbin or XACML-based systems.
• Field-level or client-side encryption, key management, HSM/KMS and KMIP integration.
• Lucene-based search, Atlas Search, vector search, hybrid retrieval and RAG patterns.
• DCAT or Dublin Core, data cataloguing, data mesh and federated data architecture.
• Event-driven architecture and distributed-systems consistency patterns such as saga and eventual consistency.
• Oracle, COBOL or other mainframe and legacy platform experience; time-series or geospatial data; constrained or edge hardware deployment.
• AI-assisted development workflows and agentic coding tools.

Culture & Benefits

• Engagements typically last three to twelve months, with a strong likelihood of continuing onto the next programme.
• Some roles begin part-time during the design phase before moving to full-time delivery.
• Predominantly remote work with periodic onsite attendance and occasional client-site travel.
• Work is performed through client-supplied devices or VDI with VPN access and defined information-handling constraints.
• Small, focused, multi-disciplinary teams working alongside partner organisations and other suppliers.

Hiring process

• Programmes are mobilising or entering contract negotiation, with start dates varying by engagement.
• SC clearance is the standard route; candidates with BPSS only may be considered where SC sponsorship is possible, with clearance taking roughly three months.