Crowdlinker is hiring a

Senior Back-End Developer (Contract)

Barcelona, Spain

(local applicants only - Barcelona)

Crowdlinker is an end-to-end digital product studio based in Toronto and Barcelona with a relentless focus on our customers. We connect people through technology by being the strongest link between companies, their ideas, and their clients. We do so by excelling at digital strategy, creative design, full-stack development of websites & web/mobile apps, and product marketing. Our clients include large startups like Freshbooks, Second Closet, League, and TopHat, as well as enterprises like Unilever, Nestlé and MLSE. We create cutting-edge applications using the latest technologies and design them with exceptional user experiences.

As a Senior Back-End Developer, you will be responsible for ensuring that user stories and features of projects are executed using sound development practices and the most up-to-date and reliable tools. You will collaborate with product managers and designers to ensure that the problem is being solved in the correct manner. Every team member at Crowdlinker is equally responsible for the success of the project as a whole and so you will bring a strong level of organization, communication and accountability to the work that you do.

Crowdlinker is seeking a Senior Back-End Developer with a back-end focus on PHP (Laravel framework). We are looking for someone to be a team lead, and so a strong understanding of the back-end is needed. We are looking for developers with an obsession for clean, well-structured coding practices who think about the sustainability of the products they build.

You will be working full-time on a client project for a minimum of 6 months that is one of the largest providers of children’s video content on YouTube, and make extensive use of YouTube’s APIs to build internal tools that help them manage a network of over 300 channels across dozens of major brands.

Please only apply if you meet the requirements! You will need to be able to hit the ground running, so make sure you understand the preferences we are looking for.


Must Haves:

  • 6+ years of professional web / mobile application development experience.
  • Fluent in English (Native preferred as client is based in London, UK)
  • Excellent knowledge of PHP programming language
  • Excellent understanding of Laravel
  • Experience working with SQL databases like PostgreSQL/MySQL
  • Experience working with NoSQL databases (MongoDB, DynamoDB, Redis, etc.)
  • Understand database design principles and the strengths and weaknesses of an ORM
  • Experience working with REST APIs
  • Basic knowledge of JS frameworks/libraries like React and Express
  • Experience with a variety of 3rd party Integrations like Stripe, Twilio, etc
  • Experience designing application architectures and working with technologies and concepts as unit testing, TDD, and continuous integration.
  • A sound understanding of design concepts and best practices required to build systems with considerations for scalability, performance, maintainability, testability, and extensibility
  • Experience leading and mentoring other developers.
  • Strong understanding of project management tools in the Atlassian Suite (Jira, Bitbucket, Confluence etc.)
  • Experience working with Agile principles.
  • Impeccable written and verbal communication skills as you will be working closely with designers, product managers and sometimes clients.
  • Experience with version control, ideally Git
  • Proficient in writing maintainable CSS / SCSS with a strong understanding of Flexbox & experience working with responsive web design frameworks, such as Bootstrap / Zurb Foundation.

Nice to Haves:

  • Strong proficiency in PHP7
  • Strong understanding of AWS
  • Thorough understanding of Laravel and its core principles
  • Has experience using file versioning tools such as GitHub
  • Has experience using authentication processes such as JWT and the oAuth2 protocol
  • In depth knowledge of object-oriented PHP and Laravel 5 PHP Framework
  • Hands on experience with SQL schema design, SOLID principles, REST API design 
  • Software testing (PHPUnit, PHPSpec, Behat)
  • MySQL profiling and query optimization
  • Creative and efficient problem solver
  • Understanding of web application development life cycle from concept stage to delivery and post launch support
  • Has an entrepreneurial work ethic and enjoys taking a problem solving approach
  • Ideally has experience of building applications in the digital video and/or online advertising industry


  • Supporting management in architecting new business solutions
  • Making decisions on the direction of backend development
  • Carrying out code reviews and finalising builds for QA and Deployment
  • Mentoring junior colleagues
  • Responsible for implementing and enforcing good standards and practices at all times
  • Dedication to quality code with commitment to testing and continuous improvement
  • Keeping up to date with emerging web technologies and application development techniques
  • Developing a suite of components that can be used across multiple web applications
  • Taking feedback from the business and translating these into tickets to keep improving the usability of web applications
  • Evolve Web Applications to keep pace with continuously improving backend capabilities and new business/client requirements
  • Using task management applications such as JIRA to aid in managing your workload across numerous projects
  • Breaking down business requirements into actionable tickets to be carried out by the team
  • Coordinating with co-developers and keep the Technical Lead and Project Manager well informed of the status of development effort
  • Developing, recording and maintaining cutting edge web-based PHP applications
  • Demonstrable experience in building innovative, state-of-the-art applications
  • Preparing and maintaining applications utilizing standard development tools
  • Prioritising and coordinating effectively across task progress, evaluations, suggestions, schedules along with identifying and dealing with technical and process issues
  • Documenting the development process, architecture, and standard components
  • Keeping abreast of new trends and best practices in web development


What’s in it for you?

  • Gain experience working with a team of experienced developers.
  • Competitive compensation.
  • Learn and implement the latest and greatest in new frameworks and technologies.
  • A ground-level opportunity to join a growing company early and accelerate your career.
  • Code with us the sensible way, using continuous integration, automated testing and deployment, proper testing/staging servers, Git repos with proper branching and all other practices that make developers’ lives easier overall.
  • A strong culture of excellence, mutual mentorship, and transparency.
  • The chance to work in fully operational, cross-functional product teams, giving you the opportunity to enhance your understanding about design, digital marketing and product management.


Duration of the role

This is a full-time contractor role for a minimum of 6 months with the option to extend. 


How to apply

In your application, please include:

  • A link to your GitHub profile if you have one.
  • A link to your LinkedIn profile if you have one.
  • A link to your portfolio of work if you have one.
  • A summary of how you would be able to make a difference on our team.

You may include a traditional resume and cover letter as well, although it is not required.

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