Sean Michael Dugan
Senior backend & full-stack engineer

Sean Michael Dugan.

Open to Staff and Senior backend roles.

Based in Austin, TX
Download resume (PDF) ✉ lunacity360@gmail.comLinkedIn (opens in a new tab)GitHub (opens in a new tab)
01 / Resume

Experience

Full history →

to

Dun & Bradstreet

Senior Software Engineer, Hoovers / DataVision

Senior Software Engineer (2021 – 2026) · promoted from Software Engineer (2018 – 2021)

  • DataVision technical lead: carried the technical-lead duties—backend architecture decisions, scrums and standups, and critical bug fixes—and onboarded and mentored new hires.
  • Visitor Intelligence ingestion: designed and owned the application-side S3 loaders ingesting canonicalized data that another team’s upstream AWS Lambdas aggregated; extended them into a loader framework, ending as the only engineer left on the product.
  • Connector framework: designed and built the framework behind every DataVision export type, from CRM connectors (Salesforce, HubSpot, Marketo) with per-connector scheduling to scheduled exports; iterated on it for years.
  • Agentic MCP services: migrated monolith features into a shared agentic Python MCP (Model Context Protocol) codebase, exposing platform capabilities as production agent-callable tools.
  • Authentication platform: designed, built and supported a hybrid JWT session architecture spanning the legacy Lift webapp and the new Play service, which became the auth layer every production MCP service and AI agent relies on.
  • Usage metering: built billing metering on Akka Cluster with per-site workers, then moved its hand-off from a Postgres SKIP LOCKED queue to Redis Streams.
  • Resiliency hardening: drove adoption of circuit breakers, Guava caches, and backoffs, hardening sensitive synchronous Lift web threads while rewriting them as asynchronous Play endpoints with pac4j security.
  • Scala
  • Akka
  • Play
  • PostgreSQL
  • Redis Streams
  • Elasticsearch
  • Python / MCP
  • React / TypeScript

to

FATHOM Water Management

Software Engineer II

Growth period moving from Java / Spring Boot to Scala, Akka, and functional programming.

  • Integrations: moved from Java / Spring Boot to Scala, Akka, and functional programming; delivered actor-based REST and SOAP integrations with meter-vendor head-end servers, replacing unstable partner interfaces that were blocking major implementations.
  • Meter data: scaled high-throughput meter data collection on Akka Cluster with a reactive, fault-tolerant pattern, and contributed to multi-tenant alarm and event-notification pipeline reworks on AWS.
  • Partners and deployments: worked out technical approaches for new partner integrations with partner technical contacts, and handled customer deployments and pilot demos.
  • Cloud platform: laid groundwork for a Scala / Nashorn platform running JavaScript services on AWS (S3, SQS, DynamoDB).
  • Scala
  • Akka Cluster
  • Java / Spring Boot
  • REST / SOAP
  • AWS
  • Ansible

to

DaVincian Healthcare

Software Engineering Intern → Software Engineer

Revenue Cycle Management SaaS for healthcare.

  • Messaging: designed a publish/subscribe architecture between microservices on the core Revenue Cycle Management product (Java, Spring Boot, ActiveMQ / JMS).
  • Routing service: built a service that audits and routes real-time and batch patient financial-screening requests to PNC Bank and TransUnion over REST and SFTP.
  • Security: replaced the legacy security service with one built on Spring OAuth2 and JWT.
  • Tooling: moved the codebase from CVS to Git with a Gradle build, and built an HL7 test-message service for in-house testing.
  • Testing: wrote JMeter stress tests and fixed Hibernate concurrency issues.
  • Java
  • Spring Boot
  • ActiveMQ / JMS
  • OAuth2 / JWT
  • JPA
  • Gradle
  • HL7
  • JMeter
  • Hibernate

2014 – 2015

Statek Gracja

Client website work

  • Website: built the original Polish-language website for Statek Gracja, a Lake Nysa sightseeing boat: cruise times and prices, private charters, directions and contact.
  • Admin form: added an admin form the owner used to update prices, promotions and upcoming cruises.
  • Website
  • Admin form

Jan 2012 – Oct 2013

Primus Real Estate

Web Developer / Web Administrator

  • Website: maintained the company’s commercial-property website (PHP, HTML, jQuery).
  • Digital design: Photoshop and other digital design work.
  • Documents: kept property documents and unit vacancy status up to date.
  • PHP
  • HTML
  • jQuery
  • Photoshop
Selected work

Projects

All 14 projects →
02 / Skills

Toolkit

Foundation · 11+ years backend
Languages

Scala (2 & 3) · Java · TypeScript / JavaScript · Python · Go · SQL

Backend & FP

Scalaz · Cats · Akka (Typed, Cluster, Persistence) · Play · Lift · Spring Boot · Slick · GraphQL · Connect-RPC · REST

Data & messaging

PostgreSQL (sharded) · Redis Streams · Elasticsearch aggregations · DynamoDB · Kinesis · SQS / SNS · NATS

Security

JWT / JWKS · RS256 · AWS KMS · OAuth 2.0 · SSO · Cognito

Cloud & infra

AWS (S3, CloudFront, Lambda, CloudFormation) · Terraform · GCP · Chef · Ansible · systemd / RPM · ELK

Integrations

Salesforce · HubSpot · Marketo · Segment CDP

Frontend

React / TypeScript · RTK Query · Ember · Vue · Chart.js

Testing

Playwright · Jest · ScalaTest · specs2 · React Testing Library

Now · AI & side projects
AI & agentic

Cursor · Codex · Claude · Gemini · Grok Bot · Python MCP services

Harnesses & release

Cursor cloud agents · AGENTS.md · release-kit · Docker Compose · GitHub Actions

Local AI

Ollama · pgvector hybrid retrieval · Embeddings · LLM-as-judge evals

Games & 3D

three.js · Godot · Phaser · react-three-fiber · Objective-C (iPad)

03 / Education

Education

2015

B.S. Computer Science

St. Edward’s University · Austin, TX

Archive

All projects(14)

Browse the full catalog by category and recorded years.

Contact

Let’s talk about Staff and Senior backend roles.

lunacity360@gmail.comLinkedIn (opens in a new tab)GitHub (opens in a new tab)

Download resume (PDF)