Senior Frontend Engineer – C Wire team

We at Holycode are currently looking for a Senior Frontend Engineer with strong skills and proven experience who is ready to dive into the C Wire team in our Belgrade office.

C Wire is a fast-growing AdTech startup located in Zurich, Belgrade, and Wien. They are on a mission to strengthen free and independent journalism and protect your online privacy. C Wire does this by providing a platform where advertisers can create and deliver powerful advertising campaigns. With their advertising formats, publishers can generate fair and sustainable revenue from their readers, and they do it in a non-creepy way: “We do contextual advertising, using our own proprietary technology. We do not collect and share your data.”

How do they do it?

C Wire deals with a lot of data, and a lot of traffic. Really, a lot!

They get requests every time you load an article on your favorite news website. That is multiplied by the biggest news sites in Switzerland, Germany, Austria, and the UK. They scrape, store and categorize all of the articles for contextual targeting.

The heavy lifting is taken care of by their GoLang-based microservices running on an EKS cluster. Data is stored in Postgres and Clickhouse DBs and they’re able to time travel using a Flux capacitor distributed log and Pulsar.

C Wire’s creatives are built using Svelte and the self-services are developed in Vue and Nest.JS.

Engineering at C Wire:

  • They collaborate closely – they do pair programming and mob sessions.
  • They are flexible – family, hobbies and that annoying appointment at the local office all take space in your diary. Don’t worry about it, they understand.
  • They care – not only about simplicity and elegant solutions, but also about testability, operational challenges and product aspects.
  • They cherish end-to-end ownership and DevOps culture.
  • They are fast – they do trunk-based deployments and several releases a day.
  • They minimize context switches – meeting free afternoons is the rule!
  • They are metrics driven – they monitor our services and create custom metrics for our KPIs, like daily and hourly revenue.
  • They are transparent and honest.

Why do they need you?

C Wire needs to scale, provide easy-to-use self-service tools for campaign management, and optimize creatives that get thousands of views every hour. They need smart and motivated engineers to do so. Would you like to join them in this mission?


Your role:

  • As a Senior Frontend Engineer, your focus will be on developing and designing the self-service platform for campaign and creative management.
  • You’ll also design, integrate and optimize creatives on publisher sites and collect the needed metrics for reporting and billing advertisers.
  • You’ll write tests to harden your solution and design fast and reliable deployment pipelines.
  • Furthermore, you’ll work closely with the rest of the team to deploy and monitor your solutions and optimize product requirements with technical feasibility.

Your profile:

  • 5+ years of experience with frontend technologies (Typescript, Javascript)
  • Proficiency in frontend tools and technologies (HTML5/CSS3, Javascript ES6, webpack)
  • Proficiency in writing CI/CD pipelines and automated tests (GitHub Actions, CircleCI, test containers, selenium /, junit5, jest)
  • Experience with PrebidJS or other Advertising Technologies
  • Experience with Linux, Docker and container orchestration frameworks like Kubernetes
  • Knowledge in database structure, design, query languages (e.g. SQL), large data sets, distributed systems, and fundamentals of mathematics and statistical concepts is a plus
  • Knowledge in creating and scraping instrumentation data is a plus (Prometheus, Grafana)
  • Passion for collaboration and strong interpersonal skills


  • Highly experienced team
  • Familial working atmosphere in an open-minded multinational team
  • High-growth company in which you can find exciting and trend-setting challenges
  • Performance and Scaling challenges that usually only affect much bigger companies
  • Amazing product to work on
  • Competitive salary
  • All necessary equipment – up to you to decide what you prefer
  • The budget for professional improvement (courses, conferences, books…)
  • Budget for the mastery of the English language during the working hours
  • Nice office in Belgrade
  • Fully stocked kitchen (tea, coffee, fruits, soft drinks, snacks…)
  • Tournaments of table tennis, table soccer, and darts in our office
  • Opportunities to build products that really make a difference
  • Opportunities to learn and grow with us
Apply here for this position, or check out other positions that we have.