Développeur·se Web / UX-UI & CRO (H/F)

📍 Job Overview

Job Title: Développeur·se Web / UX-UI & CRO (H/F)

Company: Tiime

Location: Paris, Ile-de-France, France

Job Type: Intern

Category: Growth Operations / Marketing Operations

Date Posted: 2026-07-24

Experience Level: 0-2 Years

Remote Status: Hybrid

🚀 Role Summary

• This intern role sits at the intersection of Web Development, UX/UI Design, and Conversion Rate Optimization (CRO), focusing on enhancing user journeys and driving business growth.

• The position involves developing and integrating new web pages, landing pages, and conversion funnels, with a strong emphasis on performance, responsiveness, and accessibility.

• Key responsibilities include designing intuitive user interfaces, improving website ergonomics, and contributing to Tiime's design system.

• A significant part of the role will be dedicated to data-driven CRO initiatives, including analyzing user behavior, conducting A/B tests, and iterating based on performance metrics.

📝 Enhancement Note: While this role is listed as an internship, the blend of responsibilities in development, design, and CRO, along with the mention of a potential permanent hire, suggests a strong emphasis on practical application and a fast-paced learning environment. The role requires a candidate with a solid foundation and a proactive approach to optimizing digital experiences for business impact, aligning with growth operations principles.

📈 Primary Responsibilities

• Develop and integrate new web pages, components, and conversion funnels (landing pages for creation and accounting, conversion tunnels) using HTML, CSS, and JavaScript.

• Evolve existing websites by implementing new features, fixing bugs, and optimizing performance, loading times, and responsiveness.

• Ensure the accessibility and responsive design of all developed web components across various devices and browsers.

• Collaborate with the technical team on CMS integrations, specifically Drupal and Hubspot, ensuring seamless data flow and functionality.

• Design wireframes and mockups for new interfaces and user flows, with a primary focus on conversion optimization and user experience.

• Improve the ergonomics and clarity of user journeys from initial interaction through to form completion.

• Contribute to the maintenance and expansion of Tiime's design system, ensuring brand consistency and efficient development.

• Translate marketing and product requirements into simple, intuitive, and brand-aligned interfaces.

• Analyze user journeys using tools like heatmaps, session recordings, and analytics to identify friction points and areas for improvement.

• Design, develop, and deploy A/B tests for various elements including headlines, calls-to-action (CTAs), page layouts, and conversion funnels.

• Measure the impact of implemented optimizations and continuously iterate based on data-driven insights to enhance conversion rates.

📝 Enhancement Note: The primary responsibilities highlight a hands-on role focused on tangible outputs that directly influence user acquisition and conversion. The expectation to analyze data, hypothesize, test, and iterate is characteristic of a CRO-focused position within a growth-oriented team.

🎓 Skills & Qualifications

Education: Bac+4/5 (Master's degree or equivalent) in Web Development, Digital Design, Engineering, or a related field. An atypical or self-taught background with a strong portfolio will also be considered.

Experience: While this is an internship, prior experience or a strong demonstrated interest in web development, UX/UI design, and CRO is highly valued. A portfolio showcasing relevant projects is essential.

Required Skills:

• Proficiency in HTML, CSS, and JavaScript.

• Experience with at least one front-end framework.

• Strong UX/UI design sensibility and proficiency with a design tool such as Figma.

• Genuine interest in conversion optimization and data analysis; ability to understand website performance drivers.

• Familiarity with analytics tools (e.g., Google Analytics, Google Tag Manager - GTM).

• Rigor, curiosity, autonomy, and a commitment to delivering high-quality work. Preferred Skills:

• Experience with Hubl.

• Familiarity with CMS platforms like Drupal and Hubspot.

• Previous experience with A/B testing tools (e.g., AB Tasty, Kameleoon, or similar).

• Understanding of entrepreneurship and the SaaS/Fintech landscape.

• Experience with wireframing and prototyping tools.

• Knowledge of responsive design principles and web accessibility standards.

📝 Enhancement Note: The educational requirement is flexible, emphasizing practical skills and portfolio over a specific degree, which is common for roles focused on immediate impact and demonstrable ability in dynamic tech environments. The inclusion of "Hubl" as a plus suggests a specific internal tool or framework that candidates with prior exposure would find advantageous.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Showcase a minimum of 3-5 distinct projects demonstrating a blend of web development, UX/UI design, and CRO initiatives.

• For development projects, include examples of responsive web pages, functional components, or integrated features.

• For UX/UI projects, present wireframes, user flow diagrams, high-fidelity mockups, and prototypes that illustrate problem-solving and user-centric design.

• Crucially, for CRO projects, provide case studies detailing specific A/B tests conducted. This should include hypothesis formulation, test design, implementation, data analysis, and quantifiable results (e.g., conversion rate improvements, engagement metrics).

• Highlight any contributions to design systems or style guides. Process Documentation:

• Detail the process followed for developing and integrating web pages, from initial concept to deployment.

• Explain the methodology used for user research, ideation, and design of new interfaces or user journeys.

• Describe the end-to-end process for conducting A/B tests, including hypothesis generation, setup in testing tools, data analysis, and reporting.

• Demonstrate understanding of performance optimization techniques and how they are applied during development.

📝 Enhancement Note: A robust portfolio is critical for this role, as it serves as the primary evidence of a candidate's ability to execute across development, design, and performance optimization. The emphasis on A/B testing case studies and quantifiable results is paramount for demonstrating CRO proficiency.

💵 Compensation & Benefits

Salary Range: As this is an internship role, compensation will be based on French internship regulations and candidate profile. For a 6-month internship in Paris at Bac+4/5 level, the legal minimum remuneration (gratification) is approximately €4.35 per hour. However, Tiime offers compensation "selon profil" (based on profile), which may exceed this minimum, especially for candidates with strong relevant skills and a compelling portfolio. A typical range for a competitive internship could be between €1,000 - €1,500 per month, depending on experience and demonstrated abilities.

Benefits:

• Gratification/Remuneration based on profile.

• Meal vouchers (Tickets restaurant).

• Partial remote work flexibility, allowing for a hybrid working arrangement.

• Potential for permanent hire upon successful completion of the internship or work-study program.

Working Hours: The standard working hours are approximately 40 hours per week, typical for a full-time internship in France, allowing for comprehensive engagement with the team and projects.

📝 Enhancement Note: The salary range is an estimation based on French internship regulations and market practices for similar roles in Paris. The "selon profil" aspect indicates that Tiime is willing to compensate candidates who demonstrate exceptional skills and potential, making a strong portfolio and interview performance crucial for maximizing internship compensation.

🎯 Team & Company Context

🏢 Company Culture

Industry: Fintech, SaaS (Software as a Service), Accounting Software, Business Management Tools. Tiime operates in a rapidly evolving digital landscape, aiming to simplify entrepreneurship and accounting through technology.

Company Size: Tiime has grown significantly, serving over 300,000 entrepreneurs and 3,000 accounting firms. While the exact employee count isn't provided, the scale of operations and recent milestones (payment institution license, PDP registration) suggest a company with a substantial and growing team, likely in the range of 100-500 employees.

Founded: 2015. Tiime has established itself as a key player in the French market, demonstrating sustained growth and innovation.

Team Structure:

• The role reports to the Marketing/Growth team, with close collaboration with the Product team. This indicates a cross-functional operational structure where marketing initiatives are tightly integrated with product development.

• The "Growth" aspect suggests a performance-oriented team focused on user acquisition, activation, and retention, requiring strong analytical and execution skills.

• The team likely comprises specialists in digital marketing, product management, data analysis, and engineering, fostering a collaborative environment for achieving growth objectives. Methodology:

• Data-Driven Decision Making: A core methodology will be the continuous use of analytics, heatmaps, and session recordings to understand user behavior and identify optimization opportunities.

• Agile Development & Iteration: The role involves agile practices in web development and CRO, with a focus on rapid prototyping, testing, and iterative improvements based on performance data.

• Cross-Functional Collaboration: The close link between Marketing/Growth and Product teams emphasizes a collaborative approach, ensuring that development efforts align with business goals and user needs.

Company Website: https://recrutement.tiime.fr

📝 Enhancement Note: Tiime's positioning as a "super app" for entrepreneurs and its recent regulatory achievements highlight its ambition and seriousness in the fintech space. The company culture is likely fast-paced, innovative, and focused on measurable impact, demanding a proactive and analytical mindset from its team members.

📈 Career & Growth Analysis

Operations Career Level: This is an Intern level position, offering foundational experience in a multi-disciplinary operational role. It's designed for individuals early in their careers seeking to gain practical skills in web development, UX/UI design, and CRO, with a direct impact on business growth.

Reporting Structure: The intern will report to a manager within the Marketing/Growth team, with day-to-day guidance and collaboration expected from team members and potentially a dedicated mentor. Close collaboration with the Product team is also a key aspect of the role.

Operations Impact: The intern's work will directly influence key growth metrics such as website conversion rates, user acquisition funnel performance, and overall user experience. Success in this role contributes to Tiime's ambitious goals of becoming a leader in the French accounting software market and supporting a significant portion of entrepreneurs.

Growth Opportunities:

• Skill Development: Significant opportunities to develop and refine skills in front-end development (HTML, CSS, JS, potentially frameworks), UX/UI design (Figma, wireframing, prototyping), and CRO (A/B testing, analytics, user behavior analysis).

• Industry Exposure: Gain hands-on experience in the dynamic Fintech and SaaS sectors, understanding the unique challenges and opportunities in digital business growth.

• Career Path: A strong performance and demonstrated aptitude during the internship can lead to a permanent hire, potentially opening doors to Junior Developer, UX/UI Designer, or CRO Specialist roles within Tiime or the broader operations field.

• Mentorship: The role is structured to provide guidance from experienced professionals in marketing, product, and development, facilitating learning and professional development.

📝 Enhancement Note: The internship is positioned as a valuable stepping stone, offering a broad introduction to key operational functions that drive business growth. The potential for a full-time offer is a significant growth opportunity for successful interns.

🌐 Work Environment

Office Type: Tiime offers a Hybrid work environment, combining in-office collaboration with remote flexibility. This suggests a modern approach to workplace culture, balancing the benefits of in-person teamwork with the autonomy of remote work.

Office Location(s): The role is based in Paris, specifically at 15 Rue Auber, 75009 Paris. This central location in a major European business hub likely provides good accessibility via public transportation.

Workspace Context:

• Collaborative Environment: The hybrid model and cross-functional nature of the role suggest an environment that encourages collaboration, brainstorming, and knowledge sharing, both in person and remotely.

• Tools and Technology: Interns will have access to industry-standard tools for development, design (Figma), analytics (Google Analytics, GTM), and CRO (testing platforms), alongside CMS integrations (Drupal, Hubspot).

• Team Interaction: Opportunities to interact with a diverse team of developers, designers, marketers, and product managers, fostering a rich learning environment.

Work Schedule: The standard work schedule is approximately 40 hours per week. While hybrid, specific in-office days may be determined by team needs and collaborative requirements, offering flexibility within the operational framework.

📝 Enhancement Note: The hybrid work model in Paris indicates a professional and adaptable work environment. The focus on collaboration and access to modern tools will be key for an intern looking to immerse themselves in a growth-focused operations team.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: Review of CV and portfolio to assess qualifications and fit for the role. Strong emphasis will be placed on the portfolio's demonstration of relevant skills and project outcomes.

• Technical/Skills Assessment: This may involve a technical test or a discussion focused on your web development, UX/UI, and CRO knowledge. Expect to walk through specific projects in your portfolio, explaining your thought process and contributions.

• Case Study/Challenge: You might be presented with a hypothetical scenario or a real-world problem related to user journeys or conversion optimization. You'll be expected to propose solutions, potentially design mockups, or outline an A/B testing strategy.

• Cultural Fit & Team Interview: A discussion with members of the Marketing/Growth and Product teams to assess your work style, collaboration skills, curiosity, and alignment with Tiime's values.

• Final Interview: Potentially with a hiring manager or senior leader to discuss the role's broader impact and career aspirations.

Portfolio Review Tips:

• Curate Strategically: Select projects that best showcase the required skills: web development, UX/UI design, and especially CRO with quantifiable results.

• Tell a Story: For each project, clearly articulate the problem, your role, the solutions you implemented, the tools used, and the measurable impact (e.g., % increase in conversion, reduction in bounce rate).

• Highlight CRO: Dedicate significant attention to A/B testing case studies. Show your hypothesis, the test setup, data analysis, and the final outcome. Use visuals (charts, graphs) to present data effectively.

• Demonstrate Process: Explain your workflow for each project, from initial research and ideation to design and implementation, emphasizing your problem-solving approach.

• Tool Proficiency: Be ready to discuss your experience with specific tools mentioned (Figma, GA, GTM, testing platforms) and how you leverage them.

Challenge Preparation:

• Understand the Goal: For any challenge, focus on understanding the business objective (e.g., increase sign-ups, improve lead quality, reduce drop-offs).

• Structure Your Approach: Outline your problem-solving process: identify the issue, gather data (or hypothesize data needs), propose solutions, prioritize them, and define how you'd measure success.

• CRO Mindset: Think in terms of hypotheses, experiments, and data-driven validation. Consider different CRO tactics relevant to the scenario.

• Design Thinking: If design is involved, think about user needs, journey mapping, and iterative design principles.

• Communication: Be clear, concise, and confident in presenting your ideas. Be prepared to justify your recommendations.

📝 Enhancement Note: The interview process heavily emphasizes practical application and demonstrable results, particularly through the portfolio. Candidates should prepare to articulate their thought process and the impact of their work with data.

🛠 Tools & Technology Stack

Primary Tools:

• Web Development: HTML, CSS, JavaScript. Experience with a front-end framework is a plus.

• CMS: Drupal and Hubspot are mentioned, indicating experience with these platforms or similar enterprise CMS is beneficial.

• Design & Prototyping: Figma is explicitly mentioned as a required tool for UX/UI design, wireframing, and prototyping.

Analytics & Reporting:

• Web Analytics: Google Analytics (GA) is a core tool for understanding user behavior and website performance.

• Tag Management: Google Tag Manager (GTM) is essential for managing tracking codes and implementing analytics.

• User Behavior Analysis: Tools like heatmaps and session recording tools are used to identify user friction points.

CRM & Automation:

• CRM/Marketing Automation: Hubspot is indicated as a relevant platform, suggesting familiarity with its capabilities for lead management, marketing campaigns, and CRM functions.

• A/B Testing Platforms: Tools like AB Tasty, Kameleoon, or equivalent are preferred for designing and deploying conversion rate optimization tests.

📝 Enhancement Note: Familiarity with the specified tech stack, particularly Figma, Google Analytics, GTM, and ideally Hubspot or similar marketing automation/CRM tools, will be a significant advantage. The role requires an individual comfortable working with these systems to drive performance.

👥 Team Culture & Values

Operations Values:

• Impact-Driven: A strong emphasis on achieving measurable results and directly contributing to business growth through development, design, and optimization efforts.

• Data-Centric: Decisions and optimizations are guided by data analysis, user behavior insights, and the outcomes of A/B tests.

• Curiosity & Continuous Learning: The fast-paced nature of the fintech/SaaS industry and the blend of disciplines require a constant desire to learn, experiment, and stay updated with best practices.

• Collaboration & Transparency: Working effectively across teams (Marketing/Growth, Product, Tech) and sharing knowledge openly is crucial for success.

• User-Centricity: Designing and optimizing experiences with a deep understanding of user needs and pain points.

Collaboration Style:

• Cross-Functional Integration: Expect to work closely with product managers, fellow developers, marketers, and potentially customer success teams to ensure alignment and achieve shared goals.

• Agile & Iterative: The team likely operates with agile methodologies, encouraging frequent feedback loops, iterative development, and adaptability to changing priorities.

• Knowledge Sharing: A culture that values sharing insights, learnings from tests, and best practices to collectively improve performance and skills.

📝 Enhancement Note: The company culture at Tiime is geared towards high performance, innovation, and collaboration. Candidates who are proactive, data-oriented, and enjoy working in a dynamic, cross-functional environment will thrive here.

⚡ Challenges & Growth Opportunities

Challenges:

• Balancing Multiple Disciplines: Effectively managing responsibilities across development, UX/UI design, and CRO requires strong organizational skills and the ability to context-switch efficiently.

• Data Interpretation & Hypothesis Generation: Translating raw analytics and user behavior data into actionable hypotheses for A/B testing can be challenging.

• Rapid Iteration Cycles: The CRO process demands continuous testing and optimization, requiring a proactive approach and the ability to quickly implement and analyze changes.

• Platform Integration Complexity: Working with multiple CMS platforms (Drupal, Hubspot) and integrating various tools can present technical challenges.

Learning & Development Opportunities:

• Specialized Skill Deepening: Gain expertise in specific areas like front-end optimization, advanced UX/UI design principles, and sophisticated A/B testing methodologies.

• Tool Proficiency: Become highly proficient with industry-standard tools such as Figma, Google Analytics, GTM, and A/B testing platforms.

• Growth Marketing Exposure: Understand the principles and tactics of growth marketing and how development and design contribute to achieving growth targets.

• Industry Insights: Learn about the competitive landscape of fintech and accounting software, and the strategies used for user acquisition and retention.

📝 Enhancement Note: This internship provides a unique opportunity to tackle diverse challenges that are highly relevant to modern digital operations and growth roles, offering substantial learning and development potential.

💡 Interview Preparation

Strategy Questions:

• "Describe a time you had to balance competing priorities between development and design. How did you decide what to prioritize?" (Assesses organizational skills and decision-making).

• "Walk me through a specific A/B test you designed and implemented. What was your hypothesis, how did you set it up, and what were the results? What did you learn?" (Evaluates CRO process, analytical thinking, and impact measurement).

• "How would you approach improving the conversion rate of a specific landing page for our accounting software? What data would you look at first, and what tests might you propose?" (Tests problem-solving skills and CRO strategy). Company & Culture Questions:

• "What interests you about Tiime and our mission to support entrepreneurs?" (Assesses alignment with company vision and industry interest).

• "How do you stay updated on the latest trends in web development, UX/UI, and CRO?" (Evaluates curiosity and commitment to continuous learning).

• "Describe your ideal team environment and how you contribute to a collaborative culture." (Assesses teamwork and cultural fit). Portfolio Presentation Strategy:

• Start with Impact: Begin by highlighting the most impactful projects, especially those demonstrating significant improvements in conversion rates or user experience.

• Structure Your Case Studies: For each CRO project, follow a clear structure: Problem -> Hypothesis -> Solution (Design/Development) -> Test Execution -> Results -> Learnings. Use visuals to support your narrative.

• Explain Your 'Why': Articulate the rationale behind your design decisions and development choices. Explain why you believe a particular solution would work.

• Quantify Everything: Where possible, use numbers and data to demonstrate the success of your projects. If direct metrics aren't available, explain the proxy metrics you used or the expected impact.

• Be Ready for Deep Dives: Prepare to answer detailed questions about your technical implementation, design choices, and data analysis methods.

📝 Enhancement Note: Candidates should prepare to not only showcase their technical and design skills but also their strategic thinking, data-driven approach, and ability to communicate complex ideas clearly and concisely. The portfolio is the centerpiece of the application.

📌 Application Steps

To apply for this operations position:

• Submit your application through the provided link on the Tiime recruitment website.

• Portfolio Customization: Tailor your portfolio to highlight projects that best align with the job description's requirements: web development (HTML/CSS/JS), UX/UI design (Figma), and especially Conversion Rate Optimization (CRO) with demonstrable results. Focus on including at least one detailed A/B testing case study.

• Resume Optimization: Ensure your resume clearly articulates your skills in the required technologies (HTML, CSS, JS, Figma, GA, GTM) and any experience with Hubspot, Drupal, or A/B testing tools. Quantify achievements wherever possible, even if from academic projects.

• Interview Preparation: Practice walking through your portfolio projects, focusing on explaining your thought process, the challenges you faced, and the impact of your solutions using data. Prepare to discuss your understanding of CRO principles and how you'd approach optimization challenges.

• Company Research: Familiarize yourself with Tiime's mission, products (super app for entrepreneurs, accounting software), and recent achievements (payment institution license, PDP registration). Understand their target audience and market position to better articulate your interest and fit.

⚠️ Important Notice: This enhanced job description includes AI-generated insights and operations industry-standard assumptions. All details should be verified directly with the hiring organization before making application decisions.