We’re On the Beach! Since 2003, we've been rewriting the rules of how people discover, book, and experience their perfect getaway. What started as connecting people to short-haul beach holidays has evolved into something much bigger - premium beach destinations, long-haul adventures, and vibrant city breaks, and that’s just the beginning of our story.

We send around two million holidaymakers on their dream breaks every year. And we're still growing.

Powered by our deep-rooted entrepreneurial spirit, proprietary tech, curiosity and our incredible people, we’re accelerating - delivering best in class technology, the ultimate holiday app, and experiences that keep our customers coming back for more.

Ready to build the future of travel with us?

About the Role

As a Senior Software Engineer (Backend), you’ll design and build scalable applications, services and platforms across On the Beach.

This is a full-stack engineering position with a stronger emphasis on backend engineering, distributed systems and cloud-native architecture.

Our backend engineers solve a wide variety of problems. You could be working on systems responsible for communicating with external travel suppliers, processing large volumes of hotel inventory and pricing information, powering customer search experiences, or ensuring bookings move reliably through complex transactional workflows.

You’ll work across the development lifecycle and collaborate with engineers, product managers and other technical specialists to design, build, deploy and operate reliable software at scale.

What you’ll be doing day to day

• Designing and building scalable backend applications and services

• Developing APIs used by customer-facing applications and internal systems

• Integrating with external suppliers and third-party platforms

• Building systems that process high volumes of requests and data

• Designing distributed and event-driven architectures

• Working with asynchronous messaging and streaming technologies

• Solving problems around performance, latency, resilience and availability

• Improving caching and data-access strategies

• Building reliable transactional workflows

• Developing applications and services within AWS

• Deploying and operating containerised applications

• Improving monitoring, alerting and observability

• Exploring AI-assisted engineering and modern development tooling

At Senior level, you’ll be expected to understand the wider system rather than only the individual service you are working on.

You should be comfortable considering how systems behave in production, identifying failure scenarios and balancing scalability, resilience, maintainability and delivery speed.

We’re looking for strong full-stack engineers whose experience leans towards backend and platform engineering.

You’ll be a great addition to our team if you have the following skills, knowledge and experience

• Strong commercial backend software engineering

• C# and .NET or comparable experience building modern backend applications

• Designing and developing APIs

• Building distributed systems and service-oriented architectures

• Developing cloud-native applications, ideally within AWS

• Working with messaging, asynchronous processing or event-driven architecture

• Designing reliable integrations with external or internal systems

• SQL and/or NoSQL data stores

• Building scalable systems handling significant traffic or data volumes

• Performance optimisation, caching and latency reduction

• Designing for resilience and failure

• Containerisation and orchestration technologies such as Docker and Kubernetes

• Observability, monitoring and operating production systems

• Automated testing and modern engineering practices

We don’t expect candidates to have worked with every technology in our stack. Strong engineering fundamentals and evidence of solving comparable problems at scale are more important than matching every individual tool.

Beyond the technologies themselves, we’re looking for someone who:

• Can independently solve complex engineering problems

• Thinks about the customer and commercial impact of technical decisions

• Understands the trade-offs between speed, quality and long-term maintainability

• Can contribute meaningfully to technical and architectural discussions

• Communicates clearly with both technical and non-technical colleagues

• Raises engineering standards through collaboration rather than hierarchy

• Helps less experienced engineers develop

• Is comfortable working in an environment where priorities and problems can change quickly

What to expect from our interview process

After a call with our Talent Acquisition Team, We will run a 3 stage interview process. Which will consist of:
Hiring Manager meet & greet - 30 Minutes
Behavioural & ways of working - 60 Minutes
Tech Pairing & System Design - 120 Minutes, broken down into two parts (50 minutes each) with a short break and time for your questions at the end.

We want to make sure everybody has the opportunity to perform at their best. If you require any reasonable adjustments during the interview process please let the Talent Acquisition team know and they will be happy to assist.

You’ll find diverse teams at OTB, reflective of the world we live in and the customers we serve. We believe strongly that difference, not uniformity, is critical to our success. We know that better decisions happen when they are made by a range of voices, perspectives and experiences. As an equal opportunity employer, we value and welcome applications from all sections of the community.

Ways of working
Our full time hours are 37.5 per week, but we don't have rigid working hours so you can find the working pattern that's right for you. We have core working hours between 10am - 4pm, so we can collaborate and enjoy the social side of work.

We also have hybrid working so we all work from home and a minimum of one day every two weeks in our Dublin workspace.