> Markdown version of [/jobs/ext/1280165-api-canonical-model-engineer-senior-mid](https://www.wearedevelopers.com/jobs/ext/1280165-api-canonical-model-engineer-senior-mid). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # API & Canonical Model Engineer (Senior / Mid) - **Company:** FANISKO LLC - **Location:** United States - **Experience:** Experienced - **Contract:** Permanent contract - **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Encodings, Command-Query Responsibility Segregation (Software Development), PostgreSQL, OAuth, OpenID, Redis, Ui Patterns, Zero Trust Network Access, Openapi, Modern Ui, Spring Cloud, ReactJS, Amazon ElastiCache, Spring-boot, Core Api, AngularJS, Apache Kafka, Data Management, Api Design, Api Gateway, Restful APIs, Crosswalk, Legacy Systems, Microservices - **Published:** July 15, 2026 - **Apply:** https://www.indeed.com/viewjob?jk=24f3b2c68037f910 ## About the Role * 5+ years of Java / Spring Boot building production microservices * REST API design with contract-first OpenAPI v3; API gateway experience (Spring Cloud Gateway or similar) * Distributed-systems patterns in production: CQRS, saga, transactional outbox, idempotency,compensation/rollback * Data-modeling fundamentals: logical/physical modeling, identifier design, PostgreSQL (including JSONB trade-offs) * Kafka-based integration * Security: OAuth2/OIDC, workload identity, zero-trust patterns, row-/column-level security * For the console track: React or Angular with data-dense UI patterns - editable grids, workflow/approval queues, audit trails ## Description You will design the canonical data model that all source data maps into, and build the serving layer that exposes it: CQRS read APIs over the golden record, a BFF and API gateway composing ~60 modern UI screens, a mediated write path back to legacy systems of record, an eligibility/personalization rules layer, and the internal console practitioners use to govern mappings and steward merge decisions., * Define and evolve the canonical data model (Person, Employment, benefit domains), the Global ID scheme, and the custom-attribute extensibility model * Design the canonical Core API resource catalogue - contract-first OpenAPI v3, shaped by the canonical model rather than a 1:1 port of 300+ legacy APIs - plus BFF screen-composition conventions * Build the serving layer: BFF, API gateway, and process services as the sole consumer boundary, with CQRS read APIs and a bounded consistency window * Build the mediated write path (UI ODL system of record): sync-confirm by default, async-accept writeback via saga, transactional outbox, and compensation, with read-your-writes and pending-write handling * Build the eligibility/personalization rules layer: precompute parameters and evaluate expressions against stored data, reusing an existing evaluation library * Build the practitioner console: crosswalk editor, reference-data management, survivorship and match-threshold editors, and a daily-use steward queue - with roles, permissions, and audit * Implement service-to-service zero-trust security: workload identity, per-call authorization, gateway edge auth, and row-/column-level security, * Enterprise/canonical data-model delivery at scale (expected at senior level) * BFF and screen-composition API design * Rules or expression-engine work (relevant to eligibility/personalization) * ElastiCache/Redis and low-latency read tuning * Admin-console or data-stewardship tooling; embedding AI copilots into user workflows * Benefits administration or healthcare domain knowledge ## Related Videos - [Keeping applications secure by evolving OAuth 2.0 and OpenID Connect](https://www.wearedevelopers.com/videos/100152-keeping-applications-secure-by-evolving-oauth-2-0-and-openid-connect) - [Reducing LLM Calls with Vector Search Patterns - Raphael De Lio (Redis)](https://www.wearedevelopers.com/videos/1714-reducing-llm-calls-with-vector-search-patterns-raphael-de-lio-redis) - [An Opinionated Guide to Bulletproof APIs](https://www.wearedevelopers.com/videos/100182-an-opinionated-guide-to-bulletproof-apis) - [Get started with securing your cloud-native Java microservices applications](https://www.wearedevelopers.com/videos/123-get-started-with-securing-your-cloud-native-java-microservices-applications) - [Delay the AI Overlords: How OAuth and OpenFGA Can Keep Your AI Agents from Going Rogue](https://www.wearedevelopers.com/videos/1637-delay-the-ai-overlords-how-oauth-and-openfga-can-keep-your-ai-agents-from-going-rogue) - [API = Some REST and HTTP, right? RIGHT?!](https://www.wearedevelopers.com/videos/1675-api-some-rest-and-http-right-right) ## Related Articles - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [The 7 Most Popular Backend Frameworks for Developers](https://www.wearedevelopers.com/magazine/403-the-7-most-popular-backend-frameworks-for-developers) - [Highest Paying Tech Companies for Developers](https://www.wearedevelopers.com/magazine/220-highest-paying-tech-companies-for-developers) - [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers) - [Navigating the AI Shift](https://www.wearedevelopers.com/magazine/629-navigating-the-ai-shift) - [Dev Digest 131 - AI'm not sure about OSS](https://www.wearedevelopers.com/magazine/472-dev-digest-131-ai-m-not-sure-about-oss)