David Dieppois

Senior Full-Stack Engineer — Java · Angular · AI

Available to build

© 2026 David Dieppois. All rights reserved.

David Dieppois

Introduction

  • Full-stack software engineer with over a decade of experience building and scaling products across healthcare, finance, insurance, and legal-tech — now specializing in AI-powered systems using Java (Spring Boot), Angular, and cloud-native AI services.
  • Founder and sole engineer of OntarioSeverance.ca — a production RAG platform for Ontario employment law over 6,400+ court decisions, designed, built, and operated solo with Java (Spring Boot, Spring AI), Angular, BigQuery vector search, and Gemini on Vertex AI.
  • Practices AI-assisted development daily using Claude Code, MCP servers, and local LLMs to accelerate architecture, code generation, and testing workflows.
  • Also the creator of TenancyTrust.com — an AI-driven tenancy assistant for Canadian landlord-tenant law.
  • Focused on crafting fast, secure, and intelligent SaaS applications with clean architecture that bridge technology and human problem-solving.

Tech Stack

Builder toolkit

Java logo
Java
Spring logo
Spring
Angular logo
Angular
Node.js logo
Node.js
OpenAI logo
OpenAI
Tailwind CSS logo
Tailwind CSS
PostgreSQL & SQL logo
PostgreSQL & SQL
Google Cloud logo
Google Cloud
AWS logo
AWS
Azure logo
Azure
Claude logo
Claude
Python logo
Python
Docker logo
Docker
Java logo
Java
Spring logo
Spring
Angular logo
Angular
Node.js logo
Node.js
OpenAI logo
OpenAI
Tailwind CSS logo
Tailwind CSS
PostgreSQL & SQL logo
PostgreSQL & SQL
Google Cloud logo
Google Cloud
AWS logo
AWS
Azure logo
Azure
Claude logo
Claude
Python logo
Python
Docker logo
Docker

A decade in, I build what scales — Cloud, Java/Spring, Angular, and AI — fast, secure, and built to last.

Projects

Ontario Severance

https://www.ontarioseverance.ca

Full-stack RAG platform for Ontario employment law, designed, built, and operated solo

Founder & Sole Engineer — David Dieppois

Ontario Severance logo

Ontario Severance is a production LLM application that answers employment law questions for Ontario workers from 6,400+ real court decisions and Ontario legislation. Designed, built, and operated solo: architecture, backend, frontend, data pipeline, cloud infrastructure, CI/CD, security, and LLM evaluation.

  • Severance Calculator
  • AI Chat
  • Document Review
  • Court Cases
  • Find a Lawyer
  • Topics & News
Retrieval-Augmented Chat

RAG over court decisions and legislation with BigQuery vector search and Gemini on Vertex AI, streamed over server-sent events with citations. Parallel retrieval, a history token budget, bounded retries, and automatic model fallback. Time to first word cut from 8–19 s to 1.5–2.9 s by tuning the model's thinking level.

Severance Estimation Engine

Deterministic statutory calculations in Java (Ontario ESA and Canada Labour Code) combined with an LLM estimate grounded in comparable decisions, returned as structured JSON and checked by a second review pass. Results stream progressively: the statutory minimum appears at once, where the page used to show nothing for a median 29.5 s.

Document Understanding Pipeline

Uploads (PDF, Word, photos) are read into 29 structured fields with a JSON-schema model call. Every quoted passage is verified against the document's own text (PDF text layer or Cloud Vision OCR), and all arithmetic is done in code, never by the model. 259 of 262 facts read correctly on the evaluation set.

Case-Law Data Pipeline

Screened over 105,000 Ontario court decisions from the CanLII API with a multi-stage filter and locally hosted Qwen models (14B and 35B) on llama.cpp, avoiding per-call API cost at that volume. Output: 6,400+ summarized, embedded, and keyword-tagged employment decisions. A prompt audit against a hand-labelled set raised the share of employment cases the LLM stage keeps from 64% to 87%.

LLM Evaluation & Guardrails

Quality suites run fixed profiles against live models with rule-based evaluators and a blind model-judged comparison, used to choose models, prompts, and thinking levels. Grounding checks drop values the source does not support, alongside prompt-injection handling and an off-topic gate calibrated on 101 queries that answers without a model call.

Platform, Delivery & Security

About 6,700 statically prerendered pages (Angular SSG with hydration) on Firebase Hosting, with the API on Cloud Run. GitHub Actions deploys are keyless (Workload Identity Federation), with build and deploy isolated in separate jobs and actions pinned to commit SHAs. Firebase App Check, distributed rate limits, and a strict CSP.

Tech Stack: Java 25 • Spring Boot 4 • Spring AI • Angular 22 • TypeScript • Gemini on Vertex AI • BigQuery vector search • Firestore • Cloud Run • Firebase • GitHub Actions • CanLII API

Tenancy Trust

https://www.tenancytrust.com

AI-powered residential tenancy intelligence for Canada

Founder & Engineer — David Dieppois

Tenancy Trust logo

Tenancy Trust is an AI-powered legal-tech platform that helps Canadian tenants and landlords understand, validate, and improve their residential tenancy agreements. Built from the ground up with Spring Boot, Angular, Firebase, and OpenAI, the system automates legal reasoning by cross-referencing leases against the Residential Tenancy Act (RTA) of each province, surfacing compliance gaps, risk indicators, and actionable insights — all while staying deeply human-centric.

Lease Analysis Pipeline

Uploads, parses, and legally analyzes tenancy agreements in real-time using Java/Spring AI pipelines. Cross-checks lease clauses against provincial RTA statutes and official lease templates, while performing contextual web scans to flag landlord credibility, rent fairness, and neighborhood safety signals.

GPT-5 Legal Assistant

A fine-tuned GPT-5 agent specializing in Canadian tenancy law. It connects live to provincial RTA databases, curated CanLII cases, and official tenancy templates to provide real-time, legally grounded responses—transforming static legal research into an interactive, conversational experience.

CanLII Case & News Explorer

Aggregates thousands of Residential Tenancy court cases from CanLII and pairs them with AI-curated news on housing policy and rental reforms. Gives users legal context and visibility into real decisions shaping the rental landscape in their province.

Vision & Roadmap

Tenancy Trust is evolving toward a single mission: becoming Canada's #1 AI platform for residential tenancy guidance. The next phase brings mobile support, a public release following beta, and deeper fine-tuning of our GPT-5 tenancy model for even faster, more accurate responses. Every milestone tightens the loop between law and technology—building a future where renters and landlords can resolve issues instantly, confidently, and fairly.

Tech Stack: Java • Spring Boot • Angular • Google Cloud • Firebase • OpenAI API • CanLII Integration

Professional Experience

Senior Full-Stack Engineer

Medavie Blue Cross

Jul 2025 – Present Toronto, Canada

Driving API modernization across Java 8/11 to JDK 21/25 for a major Canadian health benefits provider. Leveraging AI-assisted development daily to accelerate architecture, code generation, and testing workflows while building next-generation data pipelines with BigQuery and Vertex AI.

  • Modernizing legacy Java 8/11 services to JDK 21/25 with Virtual Threads, structured concurrency, and modern language features to improve throughput and maintainability.
  • Implementing Flyway-based database migration pipelines to replace manual schema management, ensuring repeatable and auditable deployments across environments.
  • Generating and maintaining Swagger/OpenAPI documentation for all modernized endpoints, enabling seamless frontend and third-party integration.
  • Using AI coding assistants (GitHub Copilot, Claude) daily to accelerate development — from architecture design and code generation to test scaffolding and code review.
  • Building a BigQuery + Vertex AI MVP for intelligent claims data analysis, enabling pattern detection and predictive insights across health benefits data.
Java 8-25 Spring Boot Virtual Threads Microservices Flyway PostgreSQL Swagger/OpenAPI GitHub Copilot Claude BigQuery Vertex AI

Senior Full-Stack Engineer

PHSA – BC Provincial Health Services Authority

Aug 2024 – Jun 2025 British Columbia (remote-friendly)

Developed the Patient Summary platform from the ground up as a prototype for clinics and physicians in British Columbia. The project served as a proof of concept for a future SaaS solution, enabling secure, FHIR-compliant access to patient data. Built with Spring Boot and Angular, it supports interoperable data exchange aligned with HL7 standards.

  • Designed and implemented RESTful APIs using Spring Boot and HAPI FHIR for patient data management, PDF generation, and FHIR Bundle export.
  • Built a dynamic Angular Material interface for providers to securely view and update patient records in compliance with HL7 FHIR standards.
  • Deployed the full-stack platform to AWS with OAuth2 authentication and CI/CD via GitHub Actions.
  • Created unit and integration tests with JUnit and Karma to ensure platform reliability and maintainability.
  • Managed production deployment, support, and direct coordination with client IT teams for custom implementation and onboarding.
Java Spring Boot Spring Security Angular TypeScript HAPI FHIR HL7 OAuth2 AWS GitHub Actions iTextPDF

Senior Java Backend Engineer

Smile Digital Health (Smile CDR)

Sep 2023 – Jun 2024 Toronto, Canada

Contributed to multiple applications supporting healthcare data interoperability through HL7 FHIR. Focused on modernizing legacy APIs, enhancing system performance, and integrating new features based on evolving standards and client needs.

  • Refactored Java and Spring Boot APIs to improve performance, scalability, and maintainability while adding documentation and comprehensive unit tests.
  • Designed new architectural solutions for legacy systems to accelerate feature delivery.
  • Integrated a GraphQL-based architecture and built robust integration tests to ensure reliability.
  • Maintained a custom VS Code extension to streamline developer workflows across teams.
Java Spring Boot GraphQL Kafka Node.js AWS TypeScript Postman VS Code Extensions

Senior Full-Stack Developer (Java, React, AWS)

DMI (Digital Management, LLC)

Feb 2022 – Jul 2023 USA / Montreal (remote)

Led the development of Spring Boot microservices and AWS Lambda functions for a high-volume financial platform processing millions in daily transactions. Delivered secure, scalable backend APIs, ensured full PIPEDA compliance by resolving critical vulnerabilities, and improved system performance through microservice refactoring.

  • Led the development of Spring Boot microservices and AWS Lambda functions powering a high-volume financial platform processing millions in daily transactions.
  • Ensured full PIPEDA compliance by resolving critical vulnerabilities including XSS, CSRF, and injection risks.
  • Documented APIs using OpenAPI and implemented seamless integration between traditional services and serverless components.
Spring Boot Java AWS Lambda React OpenAPI Swagger PIPEDA

Senior Full-Stack Developer (Java, Vue.js)

Well Health Technology – Insig Health

Nov 2020 – Feb 2022 Toronto, Canada

Redesigned and migrated a legacy Node.js backend to Spring Boot for a large-scale virtual healthcare platform supporting 3,000+ practitioners and 80,000+ monthly appointments. Developed and secured microservices for appointment and patient management using Spring Security, implemented CI/CD pipelines with Docker, and improved test coverage to 83%.

  • Redesigned and migrated the legacy Node.js backend to Spring Boot for a large-scale virtual healthcare platform supporting 3,000+ practitioners and 80,000+ monthly appointments.
  • Developed and secured microservices for appointment and patient management using Spring Security, XSS/CSRF protection, and rate limiting.
  • Implemented CI/CD pipelines with Docker and raised automated test coverage to 83% for mission-critical flows.
Spring Boot Vue.js Docker Spring Security CI/CD

Senior Full-Stack Developer (Java)

Afilias (acquired by Donuts)

Aug 2019 – Nov 2020 Toronto, Canada

Migrated legacy Spring APIs to Azure using Kubernetes and Docker for the .org domain management platform. Improved performance with Redis caching and maintained production support for thousands of registrants.

  • Migrated legacy Spring APIs to Azure using Kubernetes and Docker for the .org domain registry platform.
  • Improved performance with Redis-backed caching that stabilised WHOIS lookups during peak traffic.
  • Maintained production support for thousands of registrants throughout the transition to new infrastructure.
Spring Boot Kubernetes Azure Docker Redis

Earlier engagements

  • Senior Java Integration Engineer Willis Towers Watson – Brovada
    Mar 2016 – Aug 2019 Toronto, Canada

    Integrated insurance SaaS products with carrier systems, building resilient connectors and data pipelines.

  • Java Developer Destiny Solutions
    Jun 2015 – Oct 2015 Toronto, Canada

    Delivered reporting and backend services for student information platforms used by continuing-education teams.

  • Java Developer Outside Intelligence
    Nov 2012 – May 2015 Toronto, Canada

    Built NLP-driven risk classification and data mining pipelines that surfaced intelligence for financial clients.

Education

Master's in Computer Science & Information Systems

MIAGE (Computer Methods Applied to Business Management) – MBA option

IUP MIAGE, University of Picardie Jules Verne

Intensive five-year curriculum combining enterprise software engineering, data strategy, and MBA-level leadership foundations.

Université de Picardie Jules Verne logo
2007 – 2012 Amiens, France

Articles

Coming soon!