CryptoNext Security is a European deeptech company and pioneer in post-quantum cryptography (PQC). Founded in 2019 after 20+ years of academic research at INRIA, CNRS and Sorbonne University, we protect organizations from the quantum threat through PQC and crypto-agility solutions.

Identified by Gartner among the Top 5 PQC players worldwide and the first European company selected by NIST's NCCoE for its initiative on Migration to Post-Quantum Cryptography, we work with leading clients in finance, defense, governments and critical infrastructures (including the Banque de France, the Bundesbank, NATO and the Monetary Authority of Singapore). In March 2025, we became the first company in the European Union to receive CAVP certification from NIST for all three standardized PQC algorithms.

About the role

We are looking for a Junior Product Owner with a strong UX orientation to join our Product team. Your mission: transform business and user needs into clear, structured, user-centric product specifications, so our R&D team can build features that are useful, consistent and simple to use.

You will sit at the intersection of Product, UX/UI and Engineering. You will own the translation of product vision into actionable delivery — from discovery and user journeys to wireframes, user stories and acceptance criteria — and you will close the loop by validating what is shipped against the original user intent.

What you'll do

1. Structure product delivery: EPICs, User Stories & Specifications

• Break down the product vision into coherent EPICs aligned with business logic and user journeys.

• Write high-quality User Stories, including user context and objective, detailed acceptance criteria, edge cases and business rules.

• Produce clear, actionable functional specifications that developers can build from with minimal back-and-forth.

• Guarantee end-to-end traceability per feature: EPIC → User Stories → Tasks → Delivery.

• Maintain a structured, up-to-date product documentation in Jira.

2. Embed UX deeply into product definition

• Actively participate in product discovery and user need investigation.

• Translate every business need into a clear UX intent for the end user.

• Build and maintain Personas, User Journeys and functional flows.

• Identify friction points along the user experience and propose concrete improvements.

• Make sure every User Story carries an explicit UX value (not just a technical or business one).

• Integrate into specifications both UX rules (user feedback, readability, accessibility, etc.) and real-world use cases (not theoretical ones).

3. UI/UX design

• Produce low-fi and mid-fi wireframes to support discussions with Product, Design and Engineering.

• Collaborate efficiently in Figma with the UX/UI designer and developers.

• Describe interface states and interactive behaviours precisely.

• Ensure consistency across complete user journeys — not just isolated screens.

• Formalize end-to-end scenarios including normal paths and edge cases, and anticipate unexpected user behaviours.

4. UX validation and functional quality

• Define testable acceptance criteria for every story.

• Take an active role in product acceptance testing: functional verification and UX verification (fluidity, clarity, ease of understanding).

• Make sure what is delivered matches the original product and UX intent.

5. Continuous improvement loops based on usage and data

• Measure and analyse user behaviour on our products.

• Leverage qualitative feedback combined with usage data.

• Propose concrete product iterations and formalize them properly in the backlog.

What we're looking for

• Specification writing — ability to write clear, exploitable deliverables for developers: EPICs, User Stories, usage-oriented functional specifications.

• Figma collaboration — comfortable using and collaborating in Figma to produce and iterate on wireframes.

• First UX/UI experience — internship, junior position, side project or coursework where you contributed to UX deliverables (personas, journeys, wireframes, usability work).

• Structured mindset — you naturally prioritize, break down complex problems, and approach delivery iteratively.

• Product / user empathy — you start from the user's reality, not from features in isolation.

• Languages — professional working proficiency in English and French (written and spoken).

Nice to have

• Hands-on experience with Jira (or a similar product management tool).

• Exposure to Agile / Scrum ceremonies (refinements, sprint planning, reviews, retrospectives).

• Basic familiarity with product analytics tools or usage data analysis.

• Curiosity for cybersecurity, cryptography or B2B deeptech environments — you don't need to be an expert, but you want to learn.

What’s in it for you at CryptoNext

• A competitive salary tailored to your experience.
• A hybrid working model based in Paris.
• Opportunities for international travel based on project needs.
• The chance to lead a talented team at the forefront of post-quantum cryptography.
• A collaborative and forward-thinking environment where innovation is celebrated.