Scala Engineer - Distributed Ledger Technology

Scala Engineer – Distributed Ledger Technology Location: UK-based with client site travel as required Clearance: Active SC required, NPPV3 highly desirable (we can facilitate NPPV3 if needed) Engagement: Outside IR35 Start Date: Rolling — current and upcoming projects available Overview: OB Collective is seeking an experienced Scala Engineer to help build and deploy a next-generation distributed data infrastructure for a UK Government client. This is a foundational hire, shaping not just the technical implementation but also the delivery team design, assurance approach and long-term architectural roadmap. The platform supports cross-agency data workflows, immutable audit trails and cryptographic assurance of data in transit. This role will be central to delivering cryptographically secure, schema-bound applications based on a proven distributed ledger technology (DLT) codebase with production validation in national security environments. Key Responsibilities: • Lead the development of Scala-based modules that interface with cryptographic signing logic, validator nodes, and data lineage services • Optimise and maintain graph-like ledger structures, ensuring performance and resilience at scale • Contribute to the evolution of smart contract–like policy enforcement components for access, validation, and metadata control • Collaborate with DevOps, data architects, and security leads to deliver end-to-end features in high-assurance environments • Support test coverage, documentation and knowledge transfer to both clients and internal delivery teams Essential Skills & Experience: • 5+ years Scala development experience in production-grade systems • Deep familiarity with JVM-based architecture, functional programming and concurrency models • Experience working with distributed ledger / blockchain technologies, ideally with schema validation and consensus design exposure • Strong understanding of cryptographic patterns (e.g. signature schemes, immutability, audit trails) and when/how to apply them • Previous work in regulated, secure, or public sector environments e.g. Central Government, Defence, Financial Services, or high-assurance systems • Experience with build pipelines, containerisation and monitoring tools (e.g. GitHub Actions, Docker, Prometheus) Desirable: • Experience working on real-time or high-integrity systems (e.g. digital identity, sensitive data exchange, aerospace, or regulated comms) • Familiarity with RDF, OWL, or other graph/linked data models • Experience in schema design or JSON-LD processing at scale • Familiarity with Scala test frameworks and infrastructure-as-code tooling Types of Applications You'll Work On: • Federated Data Exchange: enabling real-time, policy-based sharing between departments and agencies without centralised control • Edge Data Validation: ensuring data integrity at the point of capture from rugged field devices, sensors, and mobile applications • AI Training Data Validation: cryptographically anchoring datasets used for model training, ensuring provenance and tamper-resistance • Hardware/Sensor Data Provenance: validating telemetry, geolocation, and biometric inputs across distributed endpoints • Secure Digital Evidence Handling: cryptographic workflows for evidence submission, video/audio chain of custody, and judicial reporting • Real-Time Regulatory Assurance: embedding compliance into procurement, grant funding, case management and enforcement processes All systems are underpinned by schema-bound, cryptographically verifiable infrastructure, supporting zero-trust access, immutability and secure multi-agency collaboration in line with UK Government Service Standards and NCSC guidance. Why Join OB Collective? We're looking for driven, ambitious individuals with a proven delivery record and an interest in working with some of the most innovative cryptographic technology in the Public Sector. If you want to help shape the UK’s approach to data sovereignty, digital trust and cryptographic security, we'd love to hear from you.