Full stack Software Developer

Ljubljana, Slovenia | Product Development | Full-time | Fully remote


At Celtra, we are looking for the help of intelligent, passionate engineers who would join us on the journey of building two world-class products. The first product (Creative Enablement or CE) has already been a growing market leader for a couple of years now, helping companies such as CNN, TripAdvisor, Bloomberg, NBCU, and Business Insider monetize their advertising inventory. With our second, younger product (Creative Automation or CA), we are chasing a much bigger opportunity by helping brands produce a massive amount of content better, faster, and more efficiently. Although its development is still in the early days, it already includes an impressive list of customers such as Spotify, adidas, Shopify, Unilever, P&G, LEGO, Lululemon, and many others. 


Meet the Celtra team


Why should you join? Let us give you an overview of what we do and how we do it to get a better idea!  

World-class products!

  • We are passionate about our two products, and we are heavily investing in both. 
  • We have a long list of exciting projects and technical challenges. For example, building collaborative, HTML, image & video editors producing high-quality output with web technologies is not an easy job. It requires walking on the line of what web technologies can do. We are processing vast amounts of data, keeping services alive with 10.000 requests per second, trying to generate thousands of ads in seconds…
  • We have an exciting tech stack, and consequently, there are many opportunities to learn new technologies. The leading technologies used on our Creative Enablement product are Scala, NodeJS, PHP, MySQL, Python, Spark, Snowflake, and you will also find GoLang, Redis, MongoDb, Apache Airflow, Kinesis... Our Creative Automation is more recent and, therefore, simpler, and it is using NodeJs, PHP, MySQL, Redis and Python. For both products, on the front-end, we use Vue.js, NPM, Webpack and vanilla JavaScript when needed. Everything runs on the AWS cloud, and the Kubernetes cluster orchestrates it.


Engineering culture

  • We care about how things are built and feel a strong affinity for technical quality. We strongly appreciate elegant software architecture and composition, using good practices like writing tests, CI/CD, automating where possible, etc. We always do code reviews to provide feedback and ensure code quality. We do product & spec reviews when it makes sense to give feedback and secure product and architecture quality. 
  • We always follow the latest technology trends and continuously research and learn new things. 
  • We are shipping frequently (weekly), and we are working towards daily deploys.
  • We like to share our knowledge. Internally, we have sessions weekly within product development & engineering. We like to know what other teams are doing, discuss the challenges we had with projects we were working on, and discuss common things such as developer tooling and design systems. Externally, we often organise meet-ups, participate at various events at universities, educating students through mentorships.
  • We are not a feature factory. We have cross-functional teams with engineers, product managers, and product designers who are crafting a solution for a problem since day one. There is a lot of fun in this phase, requiring a lot of ingenuity, hacking, and validating.
  • Sometimes we gotta get dirty and figure out why the DB is slow or why some k8s pod is not running correctly, figure out how to successfully retry a failing API request, etc.


Working at Celtra

  • We invest a lot to give insights and context to the teams, enabling and encouraging everyone to participate in product & business decisions. 
  • You can wear many hats here, not just inside engineering, where you can switch between teams, projects, and technologies, but you can also try yourself as a product manager or product designer. If you are interested, you can be on the front lines with customers. It is not unusual that our engineers fly-in to our customers, such as adidas, P&G, Unilever, etc. 
  • We are well organised and have established processes, which are here to make us more productive and better. Still, achieving results is the most important, and we do cut corners when it makes sense.
  • Team collaboration is essential to us. We are flexible and have a very inclusive environment for remote employees. However, we love the vibe in our offices too, and we will revive them as soon as possible and keep remote work as an option.  
  • We place great importance on the professional development of our employees and continuously promote a constant learning culture. Besides knowledge sharings, we invest a lot in mentoring, knowledge acquisition, and coaching. Each employee receives a yearly budget for personal education and an unlimited budget for books. 
  • Celtra is an international environment where Ljubljana and New York are the biggest hubs with headquarters in Boston. We have smaller offices in London, Singapore, San Francisco. We love that Celtronians meet in-person, and traveling between offices is something that we encourage. Hopefully, this will soon be possible again!


Your responsibilities

  • You will work on our existing and new front-end single-page applications (content editor, reviewing tools, dashboards, etc.) on the front-end.  On the backend, you will work on our REST API, a family of background services, our rendering engine... The Tech stack depends on a product (see above).
  • You will help a product manager in figuring out what is worth building.
  • Together with the product manager (and product designer, if it is a UX-oriented problem), you will work on crafting a solution. You will drive the implementation of it.
  • You will write technical specifications, do code reviews, write tests (unit, integration & end-to-end) and collaborate with the quality assurance team.
  • You will be responsible for resolving users facing issues, bugs and upgrading our product continually, which includes improving the quality of code, monitoring it in production, etc.


Our expectations

  • Have at least 2 years of experience in programming and following modern software development processes. 
  • Have experience of building single-page applications using modern web technologies (Javascript / TypeScript / CSS / HTML) and frameworks (VueJS / React / Angular).
  • Have experience with server-side principles (scaling, concurrency, etc. and back-end technologies (PHP, Python, Golang, Ruby, etc.).
  • Have understanding and experience of relational databases (e.g., MySQL) or document databases (e.g., Mongo).
  • Have experience with writing a unit, integration and end-to-end tests.
  • Show passion for learning, and help us learn too.
  • Be fluent in written and spoken English.


We appreciate:

  • Experience with TDD & CI
  • UI/UX expertise
  • Understanding of various software paradigms and architecture styles (REST, OOP, functional programming, state management, etc.)
  • B.Sc. or higher in Computer Science or a related field 


Celtra benefits

Compensation depends on experience and knowledge, but here’s what we offer in general:

  • A competitive benefits and compensation package 
  • We place great importance on the professional development of our employees
  • Comprehensive health coverage and dditional pension insurance 
  • We provide plenty of opportunities for employees to seek a more active and healthy lifestyle. We provide a dedicated budget for any kind of sport activities employees are passionate about, and we sponsor group sports activities such as basketball and yoga lessons. 
  • We provide employees with top-notch working equipment and an additional budget for your home office. 


More about Celtra 

We are Celtra (video) 

Celtra AllHands

Recent awards

Product Overview 

Hear from our CEO