Senior Full-Stack Engineer · Product & Experimentation

Senior Full-Stack Engineer - Product \& Experimentation Paris · Permanent contract · Hybrid Build the experience after the click At Dolead, we help companies turn digital acquisition into measurable business results. Today, millions of users interact with the landing pages and digital journeys we build across Europe and the United States. Our next challenge is to go further. We want to create a seamless experience from the moment someone clicks on an ad to the moment they are contacted by one of our clients’ call centers: clearer next steps, better follow-up, smarter interactions and, eventually, new experiences powered by AI. To help us build this, we are looking for a Senior Full-Stack Engineer with a strong interest in user experience, product thinking and experimentation. This is not a role where Engineering receives a finished roadmap and simply executes it. You will help shape the problems we solve, challenge the solutions and measure whether what we build actually moves the needle. Your team You will join our Perfect User Journey squad , managed by Ioanna, the team’s Engineering Lead. The squad currently includes: one Squad Lead one Front-End Engineer; one Full-Stack Engineer; But you'll also talk to Product, Data and Architecture You will become the third Engineer in the team and work closely with all of them to design, build and improve our user journeys. The squad is deliberately small and cross-functional. Product, Engineering and Business work closely together, with short decision loops and a shared focus on measurable outcomes. What you will do Build product features end-to-end You will design and develop features across the stack, from React interfaces to the Python services supporting them. While the role requires strong front-end expertise, you should also be comfortable taking ownership of the back-end components needed to deliver a complete feature. Improve high-impact user journeys Our landing pages are currently the main product area for the squad. You will work on their architecture, performance and user experience, while helping us progressively extend the journey beyond the initial conversion. The longer-term ambition is to connect the online experience with what happens afterwards: qualification, follow-up and interactions with call centers. Experiment, measure and scale We do not build features based on intuition alone. You will work with Product and Business to turn ideas into testable hypotheses, launch experiments and analyse their impact using data. Our approach is simple: PoC and Scale . Test quickly, measure honestly and invest further when the results justify it. Your impact will primarily be assessed through: conversion; revenue; product and technical quality. Contribute to technical decisions Our stack may evolve over the coming years. You will contribute to architectural discussions, challenge existing choices when relevant and help the team decide where technical investment will create the most value. We are opinionated, but not emotionally attached to our solutions. A good argument, supported by evidence, can change the direction. Work closely with the business Our Engineers are not isolated from the rest of the company. You will need to understand the users behind the numbers, the business model and the operational constraints of our clients. The role requires someone who can connect technical decisions with customer experience and commercial outcomes. What we are looking for You have significant experience in software engineering, ideally 8 years or more . You have built and scaled web products in a product-led environment. You have strong experience with React and TypeScript or JavaScript . You understand web performance, front-end architecture and