Senior Software Engineer - AI Start-up in Belfast

We are working with a newly funded AI startup in Dublin that is moving from early traction into serious scale post successfully raising funds. Backed by big-name investors, they are now making their first engineering hires outside of the founding team, and this role sits right at the heart of building the company's core technology from the ground up.

This is a true early-stage engineering position. You will not be joining a large, layered organisation with rigid processes. You will be working directly with the founders, shaping the platform, the architecture, and the way engineering is done as the business grows.

What You'll Be Working On

The focus of the role is building and owning the backend and systems layer of a real-world AI product. The work is heavily production-oriented rather than research-led. You will be responsible for designing and delivering services that run live, integrate with external platforms, process events in real time, and support complex automated workflows.

• Designing and building core APIs and backend services (Python-first environment).
• Creating and maintaining distributed services that coordinate data, decisions, and actions.
• Working on event-driven and real-time processing pipelines.
• Building integrations with third-party systems and customer platforms.
• Putting strong foundations in place for monitoring, reliability, and fault handling.
• Making architectural calls alongside the founders as the system evolves.
• Helping define coding standards, engineering practices, and technical direction.

You will have full lifecycle responsibility: from design and implementation through to deployment and running your services in production.

What They're Looking For

This is a role for an experienced, product-oriented engineer who enjoys owning problems end-to-end. The right person will likely have:

• Solid experience building backend systems that operate in production.
• Strong software engineering fundamentals and system design skills (ideally Python & React stack).
• A background in building APIs, services, and data-driven platforms.
• Comfort making technical decisions in ambiguous, fast-moving environments.
• An interest in working close to users, product, and founders rather than behind layers of process.
• A desire to be part of a small, high-calibre, in-person team.
• Interest or experience with AI/LLMs would be a nice to have, side projects welcome.

Practical Details

• Based in Dublin (city centre).
• On-site, early-stage team environment with flexibility when life happens.
• Senior / Founding-level individual contributor role.
• Up to 120k+ meaningful equity.

This is suited to someone who wants to step out of big-company constraints or late-stage scale-up silos and be part of building a company's core technology from the very beginning.

How to Apply

To apply for this role, submit your CV via the application form provided. Alternatively, to speak in absolute confidence about this opportunity, please contact Jack Tyrrell via j.tyrrell@mcsgroup.jobs.

Disclaimer

If you have a disability which means you require assistance at any stage of the recruitment process, please contact us directly to discuss. We are committed to providing equality of opportunity to all. Please note, we are receiving an exceptionally high number of applications at present and will be unable to shortlist candidates who are not meeting the specific requirements for this role. Due to the high volume of applications, we may be unable to provide individual feedback. We thank you in advance for your understanding.