AI Senior Frontend/Fullstack Engineer

Contentsquare

Location: Paris, Berlin, London
Job Type: full-time
Salary: Unknown
Posted: July 17, 2025

Job Description

Contentsquare is the all-in-one experience intelligence platform designed to be easily used by anyone who cares about digital journeys. With our flexible and scalable platform, organizations quickly get a deep understanding of their customers’ whole online journey.

We are a global leader in the experience analytics space, with a growing presence across 15 offices worldwide. We’re here to stay—and we’re looking for team members who are excited to drive impact and help us scale even further.

Our aim is to create an inclusive workplace where everyone learns and succeeds. Contentsquare has built a community of individuals who are daring, understanding, and deliberate. We invite you to join us in making the complex simpler—for our customers, their customers, and each other.

Important note: Be careful of scammers pretending to be from Contentsquare. We will never ask for money or contact you through random texts. For more information, visit our careers blog.

We're looking for a Senior Software Engineer (Applied AI) to join one of several exciting product initiatives currently in progress that leverage the latest in AI, particularly using Large Language Models (LLMs).

We are moving rapidly to leverage LLMs to reduce time to insight, make setup easier, and much more.

As our next Senior Software Engineer (Applied AI), you will be focused on product development, with a side of early product iteration. For example, we expect engineers to participate in user interviews as we validate product hypotheses.

This is an exciting opportunity to experience the agility of a startup, backed by the stability of a mature organization. We move quickly from idea to proof of concept to interview to product, ensuring that what we build provides actual value to our customers.

As LLMs and the related technologies are growing and changing rapidly, we are enthusiastic about new ideas and libraries but discerning – what we build is foundational.

We're a distributed team that operates across the US and Europe. We're open to hiring the right person remotely or in-office (hybrid) in the following countries: France, UK, Germany, Italy, Spain.

What we’re looking for

Desire to work in a fast-paced development environment where the customer is in the loop. We prefer to fail fast and start over than to learn too late that we’ve built the wrong thing.
Extensive fullstack (frontend-heavy) web application development experience (8+ years), preferably in a data-related industry.
Our product tech stack is primarily Typescript, with a variety of front-end frameworks. Proficiency in React or Vue is mandatory.
Strong opinions, weakly held about how to evaluate the performance of an LLM-based application.
Experience bringing an application built on top of LLMs from inception to market.
Ability to iterate/prototype rapidly to answer data-related using LLMs (and other ML when appropriate).
Familiarity with various LLM providers and their relative tradeoffs.
Familiarity with a variety of LLM models and their relative tradeoffs.
Experience working with and developing microfrontends.
Experience with styled components and tailwindcss.
Our product tech stack is primarily Typescript, with a variety of front-end frameworks (React, Vue, etc.). Our Backend framework is nestJS and experience with it is valuable.

Why you should join Contentsquare

We invest in our people through career development, mentorship, social events, philanthropic activities, and competitive benefits. We are always assessing the perks we offer to ensure we’re aligned with the employees' needs.

Here are a few we want to highlight:

- Virtual onboarding, Hackathon, and various opportunities to interact with your team and global colleagues both on and offsite each year

- Work flexibility: hybrid and remote work policies

- Generous paid time-off policy (every location is different)

- Immediate eligibility for birthing and non-birthing parental leave

- Wellbeing and Home Office allowances

- A Culture Crew in every country we’re based in to coordinate regular activities for employees to get to know each other and bond outside of work

- Every full-time employee receives stock options, allowing them to share in the company’s success

- We have multiple Employee Resource Groups, that offer a safe space for individuals who share common identities, life experiences, or allyship to connect, support one another, and passionately advocate for the issues close to their hearts

- And more benefits tailored to each country

🎯 Who is this job for?

This role is ideal for a Senior-level engineer with 8+ years of experience in frontend-heavy fullstack development, especially using TypeScript with React or Vue. Candidates should be skilled in building and iterating on LLM-based applications, familiar with multiple LLM models/providers, and experienced in microfrontends, styled components, and TailwindCSS. The ideal candidate is comfortable in fast-paced environments, contributes to product ideation, and has a strong user-centric mindset.

💬 Potential Interview Questions

Describe your experience developing frontend-heavy fullstack applications using TypeScript and React or Vue.
I have over 8 years of experience building scalable, maintainable web applications primarily using TypeScript with React and Vue, focusing on delivering intuitive and performant user interfaces in data-driven environments.
How have you integrated Large Language Models (LLMs) into web applications?
I have built LLM-powered features from prototype to production, iterating rapidly to validate product hypotheses, designing interfaces that deliver real-time AI insights while balancing performance and UX.
What approaches do you take to evaluate and optimize the performance of LLM-based applications?
I use a combination of latency benchmarking, user feedback, and cost-performance tradeoff analysis across different LLM providers and models to select the best solution while optimizing inference speed and resource use.
Describe your experience working with microfrontend architectures.
I’ve developed and maintained microfrontend systems to enable independent deployment and scaling of frontend modules, using techniques like module federation and custom integration patterns to ensure seamless user experiences.
How do you use styling solutions such as styled-components and Tailwind CSS in your projects?
I leverage styled-components for dynamic, scoped CSS-in-JS styling and Tailwind CSS for utility-first rapid styling, combining both where appropriate to maintain consistency and developer productivity.
Have you worked with NestJS or similar backend frameworks in fullstack projects?
Yes, I have used NestJS to build scalable backend APIs with modular architecture, integrating frontend data needs efficiently and ensuring seamless frontend-backend communication in TypeScript environments.
How do you manage fast-paced product iteration while ensuring code quality?
I adopt agile methodologies with continuous integration, automated testing, code reviews, and close collaboration with product teams to deliver incremental value without sacrificing reliability.
What strategies do you use to keep the customer involved during rapid development cycles?
I incorporate user feedback loops via prototypes, usability testing, and direct interviews to validate features early, adjusting technical plans to ensure alignment with customer needs.
Explain your familiarity with various LLM providers and model tradeoffs.
I am knowledgeable about providers like OpenAI, Cohere, and Anthropic, understanding differences in latency, accuracy, cost, and contextual capabilities, allowing informed selection based on use case requirements.
How do you foster an inclusive and collaborative team culture, especially in distributed environments?
I actively mentor colleagues, encourage open communication, participate in cultural initiatives, and promote psychological safety to ensure everyone’s voice is heard and respected regardless of location.

📋 Job Summary

Join Contentsquare as a Senior Frontend/Fullstack Engineer focused on cutting-edge AI and Large Language Models (LLMs). Work remotely or hybrid across Europe (France, UK, Germany, Italy, Spain) building innovative, frontend-heavy web applications using TypeScript, React or Vue, styled-components, TailwindCSS, and microfrontends. Bring your 8+ years of experience to rapidly prototype, iterate, and deliver impactful AI-powered solutions in a fast-paced, customer-centric environment. Enjoy flexible work policies, stock options, career growth, and a diverse, inclusive culture at a global leader in experience intelligence.