Stephen McCullough
Principal Engineer • Cloud Architect • Agentic Systems
Seasoned software architect and engineering leader with deep expertise across Ruby (Rails, Sinatra) and Python (Django, Flask, FastAPI). Co-organiser of Belfast Ruby, PyBelfast and Belfast Elixir. AWS and PMI-certified, combining hands-on engineering with strategic delivery.
Experience
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$NEW_COMPANY
Principal Software Engineer / Architect
Leading architectural transformation toward agentic workflows, decomposing monolithic features into independent microservices. Designing flexible orchestration patterns and introducing abstractions that future-proof systems for interchangeable AI-driven backends.
EXL
Cloud Architect / Principal Developer
Hands-on cloud architect contributing to legacy system modernisation using serverless technologies. Chief architect across multiple products, guiding projects from POC to MVP to production. Implemented organisation-wide CI/CD strategies and contributed as a frequent internal technical speaker.
- Elevated legacy projects to current industry standards
- Implemented seamless CI/CD pipelines
- Oversaw multi-product SDLC and architecture governance
SkillfulGorilla
Founder
Founder of a boutique software consultancy focused on building innovative, scalable, and modern software solutions across the full SDLC. Currently engaged on various internal application projects under NDA. Previously contracted to Emphasis Training Ltd (Sept 2023 - Feb 2025) to support and modernise their internal back-office systems built with Ruby on Rails.
Faria Education Group
Polyglot Software Engineer
Part of a small R&D-focused engineering team solving complex problems in the education sector. Designed and developed managed services and products with a wide range of technologies.
Futrli
Site Lead
First engineering hire in Belfast office. Led team setup, hiring, and community outreach. Delivered Python/Django and React-based product development.
ShopKeep
Technical Team Lead - Ecosystem
Led a team of six developers delivering integrations and ecosystem features. Worked across Ruby, Rails, Sidekiq, AWS, Docker and more.
Senior Engineer
Worked on rapidly scaling backend infrastructure, focusing on performance, security, testing, and deployment for high-traffic systems.
AuditComply
Programmer
Senior engineer delivering weekly product features, leading test coverage efforts, and working closely with CTO. Technologies included Python, Django, iOS/ObjC, AngularJS.
Six Degree Labs
Programmer
Built social engagement and analytics platforms for large brands. Experience with Rails, Django, Heroku deployments.
saltDNA
Programmer
Worked on world-class secure communications platform. Focus on Python, Erlang and encrypted systems.
RepKnight
Software Engineer
Built components of a real-time data visibility platform using PHP, Java, Ruby, Sinatra, MySQL, Cassandra.
Tascomi Ltd.
Software Engineer
rehabstudio
Lead Programmer
Maildistiller
Software Engineer
VHS Distribution / Sendit.com / BlackStar.co.uk
Programmer / Head Programmer / IT Manager
Atlas Communications (NI) Ltd
System Administrator
CV3.com
Programmer
BlackStar.co.uk
Programmer
Skills & Talks
Languages
AI & Agents
Leadership
Past Talks
Over the years I've spoken at ElixirConf, NIDevConf, PyCon Ireland, and various local meetups. Here are some titles - there are more in the archive.
Community
I've stepped back from organising meetups to make room for fresh voices and new energy. It was a privilege to help build these communities and watch them grow.
Belfast Ruby
Organiser
Monthly meetup bringing together Ruby developers across Northern Ireland. Handed over to fresh organisers to continue growing the community.
View meetupBelfast Elixir
Founding Organiser
Community meetup for Elixir enthusiasts, exploring functional programming and the BEAM ecosystem.
View meetuppyBelfast
Organiser
Python community meetup fostering learning and collaboration among Belfast's Python developers. Handed over to fresh organisers.