Machine Learning Engineer Porto

Machine Learning Engineer
Porto
Porto, Porto District, Portugal

About Us
Hostelworld Group, the global
- focussed online booking platform, inspires adventurous minds to meet the world and come back with
- changing stories to tell. Our customers are not your average tourists, they crave cultural connection and unique experiences that we make possible by providing an unbeatable selection of hostels in unmissable locations – all in the palm of their hand.

It is the social nature and community feel of hostels and their environment, that enable travellers to embrace journeys of discovery, adventure and meaning. We have more than 13 million reviews across 17, 800 hostels in more than 179 countries, making the brand the leading online hub for social travel. The website operates in 19 different languages and our mobile app in 13 languages.

Founded in 1999 and headquartered in Dublin, Hostelworld has a growing,
- calibre team of 280 people within Technology, Product, Global Markets, HR, Finance & Legal and Marketing Teams across our Dublin, London, Porto, Shanghai and Sydney offices. Hostelworld is listed on the London Stock Exchange and Dublin Euronext. You can read more about our story here.

LOCATION
This role is based in Portugal. We have an office hub in Porto available for those who prefer a hybrid model where you can spend time with colleagues
- person. You will need to be able to commute to our office hub as required from time to time.

Who You'll Work With
Hostelworld is structured differently than most tech companies in world, as we do not have an Engineering or Product department. Instead, we have "Growth Teams" which are full stack groups that are organised into cross functional squads. As a Machine Learning Engineer, you will play a key role in shaping the Machine Learning Science Growth Team progress on building products that help travellers find the right inventory of hostels and experiences as well as meet, hang out and travel with other travellers.

What You'll Do

• Translate business and customers problems into machine learning solutions.
• Defining hypotheses, measure and monitor the success.
• Propose, design, build, maintain and deploy machine learning solutions into production.
• Express and communicate the business and technical impact of the machine learning solutions to a variety of audiences.
• Responsible for the
  -
  - end process of designing and running experiments to serving production models at scale.
• Ensure that the solutions are maintainable, performant, scalable and debuggable.
• Automate and abstract away different repeatable routines that are present in most machine learning tasks.
• Provide support to software engineers and product managers building machine learning solutions.
• Bring the best software development and infrastructure practices to the Machine Learning science squad.

What We're Looking For
Experience & Qualifications:

• 4 years minimum work experience in a commercial environment.
• Experience with streaming or other dynamic data.
• Proficiency in machine learning concepts such as data exploration, feature engineering, model selection, training and testing.
• Proven experience in productization of machine learning solutions – libraries, packages, REST APIs, serving and monitoring.
• Familiarity with ranking and recommender systems
• Familiarity with deep learning.
• Experience with leveraging LLMs and agents for internal processes and
  - facing implementations.
• Experience with Google infrastructure tools – Vertex
  AI, GCP, Tensorflow, Gemini – is a plus.

Knowledge & Skills

• Proficiency programming in Python and SQL-like databases.
• You are proficient in at least one of the following machine learning tasks – classification, regression or clustering.
• You are familiar with at least two of the following libraries or packages –
  - learn, pandas, Spark MLlib, Tensor
  Flow or Py
  Torch.
• Ability to carefully design solutions that scale with increasing volumes of data.
• Ability to follow software engineering best practices, including requirements analysis, system design, modularity, version control, testing and documentation.

What We Offer

• Competitive salary & benefits
• Enhanced annual leave plus 3 Wellbeing Days per year
• Paid family leave (maternity, paternity, surrogacy & adoption)
• Agile working (plus a Working from Abroad Policy)
• Support for your ongoing growth & development
• Inclusive people policies (sickness, menopause, compassionate and fertility leave)
• A chance to give back to your local community with 5 paid volunteering days

OUR BEHAVIOURS

• Grow others - We fundamentally believe that investing in growing others benefits everyone, whether it's helping them develop hard or soft skills. We want learning and growing to be part of our DNA to help makes us a better team, together.
• Master it - We are obsessed with our area of expertise and enjoy developing our skills. We rarely take things at face value; we investigate, interrogate, and always look for 'the why, ' and wherever possible, we use data to find the best solution.
• Collaborate - We are in it together, for the tough stuff and the celebrations too. To achieve the best results, we need expertise from all areas of the organisation, and we wholeheartedly welcome diverse thinking.
• Adapt - We work fluidly, adapting to new information and the evolving environment while staying committed to our goals. Innovation and experimentation fuel our projects and we're never afraid to pivot.
• Deliver - Our focus is always on the end result; we value outcomes over activity. We collaborate to deliver work at speed without dropping any of our other behaviours.

We believe in talented and diverse teams that reflect the diversity of our customers and the communities in which we operate. Everyone brings different perspectives and experiences. We lay out the above requirements to guide applicants to the experiences that we believe will allow you to be successful in the role. If you don't meet them all, please consider applying if you think you can still perform the role as described.
Our vision is to be the world's leading social travel platform.

We are on a mission to help travellers find their people and create unforgettable moments together. Connections matter as much as destinations, and we are building a global ecosystem to enable them.

Since the launch of our social network in the hostelling category in 2022, Hostelworld has experienced transformational growth. We have successfully welcomed over 2. 6 million social members to our platform, proving the strong demand for connection in travel. This vibrant community is not just booking trips; they are actively engaging,
- creating, and becoming our most powerful brand advocates. The platform is rich with
- generated content, including a rapidly growing volume of customer testimonials and authentic travel stories that provide powerful social proof.

The growth in engagement is remarkable: the number of messages sent between travellers has grown significantly faster than the number of trips booked by social members, demonstrating the deep social utility of our platform. This momentum is reflected in our robust financial health, underscored by a strong balance sheet powered by an
- light,
- generative business model.

We are not just another Online Travel Agent (OTA); we have created a new category of travel altogether: Social Travel. Our singular focus on helping travellers find people to hang out with is the foundation of our strategy. It has allowed us to build a powerful and defensible market position, which attracts highly valuable customers and shifts more of our business onto our
- native apps.

While our app and social features create a sticky user experience, our true competitive moat stems from the incredibly rich, proprietary data set generated by our social network. As our community grows, so does the value of this data, creating a compounding network effect that is nearly impossible to replicate. This "social flywheel" allows us to understand traveller behaviour, predict needs, and personalise experiences in ways that generalist OTAs cannot match. It is the engine that will power our
- term, differentiated growth and solidify our position as the sole player in the Social Travel category we created.

At Our Capital Markets Day In April 2025, We Unveiled Our Ambitious Strategy To Build On Our Success And Realise Our Vision Over The Next Three Years. This Strategy Is Organised Around Five Key Themes

Strengthening the Core OTA Platform: We will continue to enhance our core booking engine, ensuring a seamless and efficient experience for our customers and hostel partners, further solidifying our position as the leading platform for hostel discovery and booking.

• Building 'Pre-Booking' Social Features: We are developing innovative features like 'Travel Plans', designed to engage users much earlier in their travel journey. These features will accelerate the creation of social profiles and drive app downloads, fuelling our social flywheel before a single bed is booked.
• Leveraging AI for an Enhanced Social Experience: We will embed AI into our
  - and
  - booking features to deliver unparalleled personalisation and value. This includes AI-powered recommendations for people to meet, places to go, and things to do, making our social network an indispensable travel companion.
• Expanding our Addressable Market: We will expand our reach and product portfolio through targeted partnerships and M&A. This will allow us to cater to a broader segment of the youth travel market and integrate new, complementary services into our social travel ecosystem.
• Building New Revenue Streams: Our social network is more than an engagement tool; it is a new platform for monetisation. We will develop new revenue streams directly from our social features, creating value for our users and our business in ways that traditional OTAs cannot.