Senior JavaScript Engineer in Barcelona or Remote

The Hotels Network

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Job Description

The Hotels Network (THN from now on) is a data platform for the hotel industry. Our monitoring and media delivery agent is currently embedded in over 10,000 Hotels and Online Booking engines, worldwide. It is responsible for transferring data to our platform and rendering tools and widgets. These allow the hotels to harvest advanced user behavioral metrics, personalize their website and trigger UI widgets to boost conversion.

The Tech Stack

Our tech stack consists of: Vanilla Javascript / Typescript, Go, PHP and Vue.js for our UI applications and dashboards. Our multi-cloud infrastructure runs on Amazon Web Services and Google Cloud. We store data in MySQL, Redis, Clickhouse and other other storage systems. We love Kafka, event based and data-streaming architecture models and building great products as fast as possible following the best practices.

Our monitoring Agent is built with Vanilla Javascript (transitioning soon to Typescript). It is the heart of everything we do. Performance is key to us just as it is for our customers. We build our monitoring agent to resiliently observe multiple services and handle large volumes of data. It deals with a lot of other services, and handles a lot of data.

Our backend consists of a series of mini/micro services built with PHP or Go embracing a Domain Driven Architecture. Testing is in our DNA and we conduct comprehensive unit and integration testing across the board. We embrace process automation wherever possible and ensure the quality and performance of our platform with SonarCloud, Sentry and Datadog.

Our solid data infrastructure is driven by our Data Engineering Team and relies on a modern, state-of-the-art platform supported by our DevOps and Infra teams. What makes THN stand out from any other player in this industry is our Data Science team, that designs and implements advanced ML/AI algorithms fueled by the massive data ingested by our Agent to help our clients predict their users behavior and improve their booking conversion. This position will play a pivotal role in ensuring our Data Science team gets the most valuable insights on our client’s users and target markets.

The Team

We are a globally distributed team of more than 70 engineers, half of them working remotely. We are organized in multiple cross functional teams and work using agile methodologies (mostly scrum). We value collaboration, team work, open communication, continuous learning and commitment.

The Agent team consists of 1 Product Owner, 1 Staff Engineer and 2 Senior Engineers. They will onboard you to the team, code and processes so that by the end of 1st month you can start finding your way through the code, push new features and extend our code coverage.

You Will

  • Analyze the nuts and bolts of our Booking Engine plug-ins system to start with during our onboarding process before moving on the Agent team full-time.
  • Contribute to improve the architecture of our Agent, identifying areas of improvement, enhance the internal APIs design and introduce new modules while improving the overall domains design.
  • Implement additional UI widgets that will be handled by our Agent at our clients applications.
  • Assist our team to drive the migration of our dependencies and the transition to TypeScript.
  • Contribute to increasing our test coverage quota by writing tests and integrating e2e tools on top of our current Jest and Cypress testing layer.
  • Contribute to the maintenance and speed of our JavaScript build pipeline, ensuring our bundle delivery is fast, performant and reliable.
  • Support, coach and mentor junior engineers, foster their capabilities and empower them to grow amongst us.
  • Become an authoritative voice of the technical capabilities of our Agent and provide core support and technical evangelism to sales and customer success departments and divisions.


  • You bring more than 5 years of programming experience with JS and embrace an Agile mindset in your daily practice.
  • Experience with web scripting or web agent development.
  • Proficiency in JavaScript (ES6), HTML5 and CSS3.
  • Sound understanding of SOLID principles for JavaScript development.
  • Experience working with Sass or CSS preprocessors.
  • Good knowledge of cross-browser compatibility.
  • Good knowledge of Web APIs and the HTTP protocol. Familiarity with Web and Service Workers will be appreciated but not required for the role.
  • You feel at ease with the DOM API, ESlint, Jest, Babel or Webpack. Bonus points for Rollup, Gulp, Vite, Cypress, PostCSS or the Web Components specification.
  • Experience in zero impact on our customers website performance.
  • Knowledge of the principles of UX and attention to detail/product ownership.
  • Familiar with agile methodologies and version control systems (Git).
  • Experience with Unit Testing, Functional Testing and/or Integration Testing.
  • A passion for good practices and clean code.
  • Proactive, with strong problem-solving skills, a team player and fun to work with.

Nice to have

  • Experience in developing complex modular web apps is a plus (especially without frameworks).
  • Knowledge of script performance optimization and Google Core Web Vitals management.
  • Prior exposure to build pipeline design and management for JavaScript bundling.
  • Experience mentoring junior engineers and teams.
  • Basic experience with PHP and MySQL

We offer

  • International environment with over 25 nationalities.
  • Continuous training: we do in and out house training. We have a selection of online resources such as O’ Reilly, Packt or Frontend Masters…
  • 100% Flexible schedule to balance work and personal life
  • Free “puentes” (when Tuesday or Thursday is a bank holiday THN will give Monday or Friday free).
  • Nice office in the Center of Barcelona.
  • Real impact on a fast-growing innovative technology company.
  • You can work from anywhere, either either from our comfy offices at the Barcelona city center or from the comfort of your home or favorite coffee shop. THN is a remote-friendly organization but we also foster in-person collaboration and provide the office space to make them happen.
  • "Flexible compensation plan” with Ticket Restaurant, Medical Insurance, Ticket Transport and Bonus for Nursery.
  • Coffee, tea, fresh fruit and Friday team breakfast.
  • Competitive compensation.
  • A harassment-free, supportive and safe environment to ensure the healthiest and friendliest professional experience fostering diversity at all levels.

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