✅ About Klar

• Klar is the Data Operating System for growing eCommerce companies - no more spreadsheets. We integrate with all their data sources to provide them with detailed insights on how to accelerate growth and increase profitability.

• We deeply empathise with the struggles of our customers - after having worked most of the last 10 years in e-commerce companies, we know their pain and built Klar to help.

• We work with over 1,000 leading eCom brands like Sunday Natural, Loop Earplugs, Holy, Maniko, Armed Angels and hundreds more use Klar to make better decisions every day.

• Our guiding principle is Do Work You Are Proud Of - we emphasize long-term quality over short-term results.

If you want to learn more about Klar, click here.

🛠️ The Klar tech stack:

We are a 100% Open Source shop and make use of industry-leading tools & technologies.

Frontend:

• TypeScript

• React & Redux

• MUI (Formerly material-ui)

Backend

• Backend for Frontend API Layer written using TypeScript & NestJS

• Backend Core is an implementation of clean architecture with event sourcing

Data, Integrations & Query layer

• Various applications written using Python3

• Kafka & Clickhouse

• Prefect 2 & Luigi workflow management

Infrastructure

• Kubernetes, Flux CD Git Ops

• CI using Github Actions

• Cloudflare Pages

🎯 About the JavaScript Engineer - Attribution and Tracking role

JavaScript Engineering at Klar, specifically in Attribution and Tracking, is a critical function that powers our entire data platform. Your primary responsibility will be to build, maintain, and enhance the mechanisms we use to collect first-party data from our customers' eCommerce stores. 📈

This includes developing our core tracking pixel—a lightweight and highly performant script that runs on thousands of high-traffic websites. You'll also work on developing and extending our browser extensions, creating new ways to gather insights and provide value directly in our customers' workflows.

You'll tackle unique challenges related to cross-browser compatibility, ad-blockers, and the ever-evolving landscape of web privacy (like ITP and cookie restrictions), ensuring our data collection is robust, reliable, and respectful of user privacy. Your code is the very first touchpoint in our data pipeline, making this role essential to Klar's success.

Read more about engineering at Klar:

Engineer outreach

📝 Requirements:

• Expert-level proficiency in vanilla JavaScript (ES6+), with a strong focus on writing code that is performant, lightweight, and has zero dependencies.

• Proven experience in developing and maintaining web tracking pixels or similar third-party scripts.

• Solid experience in building browser extensions for Chrome, Firefox, or Safari.

• Deep understanding of the DOM, browser APIs, event loop, and web security principles (CORS, CSP).

• A good, practical knowledge of TypeScript.

• You have a keen eye for performance and understand the impact your code has on the user experience of our customers' websites.

• You are comfortable navigating the complexities of cross-browser compatibility and the evolving landscape of web privacy (e.g., ITP, third-party cookie restrictions).

• You pride yourself in the quality of your work and you always try to produce code that‘s concise, readable and maintainable.

• You‘re keen on expanding your technical horizon and always open to challenge the status quo and to learn new approaches / methodologies / tools.

🚀 Our recruiting process:

1. Application Review:

We review your application. In order to make the process as efficient as possible, please make sure that all the info on your CV is up to date and that you've included all relevant information about yourself and your professional experience in your documents.

If we come to the conclusion that you could be a good fit for the position you'll receive an invitation for Step 2 (the first interview).

2. First Interview

The first interview only takes between 30 and 45 minutes and the goal is to get to know each other better. We'll talk about your motivation for joining Klar as well as your professional experience and also give you the opportunity to get to know us better and learn everything you want to know about Klar.

If both parties like what they hear and we proceed to step no. 3 we'll invite you to solve a coding challenge.

3. Coding Challenge

We've developed a few interesting challenges that are very similar to the real-world tasks you could face at Klar. You'll get an adequate amount of time to complete the challenge and submit your code back to us.

We'll swiftly review your solution and if you've managed to convince us with the solution and your approach you'll receive an invitation for the second interview.

4. Second Interview

Based on your professional experience and your fields of expertise, we'll prepare a bunch of questions to really get to know your level of proficiency. That can be anything from describing an interesting project you've worked on to talking about a hypothetical technical problem you're facing and how your approach to solving it would look like. We're trying to keep this step as fair and unbiased as possible and no, ... you don't have to write code to invert a binary tree on a whiteboard.

Like in the first interview, there will be also time for you to ask questions about our tech stack, and what it's like to work with us.

5. Meet the Co-Founders

We value strong fit and alignment within our team. This gives you and us a chance for a final check.

6. Offer

We'll personally contact you to discuss the terms of the employment with you. Welcome to the team! 🎉