# Senior Go Developer - Integration at CryptoNext Security > Open job at CryptoNext Security in Paris, France. Workplace: On-site. Source: France Dev Jobs, https://francedevjobs.com/jobs/cryptonext-security-senior-go-developer-integration-qne14wz Posted 2 November 2026. Last checked on the employer's career site: 10 November 2026. ## Facts - Company: [CryptoNext Security](https://francedevjobs.com/companies/cryptonext-security) - Location: Paris, France - Workplace: On-site - Employment type: Full-time - French: Not required - Skills: Docker, GitLab CI, Go, Java, PostgreSQL, RabbitMQ, Redis - Not mentioned in the job post: salary, visa sponsorship, relocation, where you can apply from ## Job description ### Who we are CryptoNext Security is a deeptech startup specializing in post-quantum cryptography. Our solutions help businesses and institutions prepare for a future where quantum computers will challenge traditional data security. We work with leading clients in finance, defense, and telecommunications. ### On a daily basis, you will • Build and maintain, in Go, the connectors that link CryptoNext Platform to our clients' tools (CLM, CMDB…): extracting, normalizing and exposing data through REST APIs. • Consume heterogeneous third-party APIs: handle pagination, rate limits, retries, idempotency and provider outages. • Design and evolve the API contracts exposed to CryptoNext Platform: OpenAPI and versioning. • Model and query PostgreSQL, use Redis, and process work asynchronously through RabbitMQ. • Containerize your deliverables (Dockerfile, Docker Compose) and get your changes through GitLab CI. • Instrument your services (logs, metrics, traces), diagnose incidents in staging and production, and contribute to root cause analyses. • Write the unit and integration tests that back your features, including against test doubles of provider APIs, and give QA what they need to automate the rest. • Review code and help onboard new team members. • Work directly with Product and QA. • Use AI coding tools as leverage under your own judgement, staying accountable for what lands in the repo. • Propose architecture changes and refactorings, and explain the trade-offs you accepted. ### How we work A team of six engineers, within our 15-person R&D department. Connectors live in a monorepo and follow a hexagonal architecture. Three days a week in our Paris office, the rest remote. Short feedback loops, high standards. We ship a working version early rather than polishing in isolation, and keep solutions as simple as the problem allows. **Requirements** ### The skills you'll need • Production Go: concurrency (goroutines, channels), context, explicit error handling, interfaces, modules and standard tooling (go test, go vet). • Hexagonal architecture (ports and adapters), or the ability to defend an equivalent split. • Third-party API integration: robust HTTP clients, timeouts, retries with backoff, pagination, rate limiting, idempotency. • Asynchronous processing: RabbitMQ consumers, acknowledgements, retries and failure handling, dead-lettering, backpressure. • PostgreSQL: schema design, migrations and rollbacks, indexing, reading a query plan. Hands-on use of Redis. • API contract design: REST, OpenAPI, versioning. • Unit and integration testing, with a defensible position on what belongs at which level and on what is worth testing at all. • Delivery: Docker and Docker Compose, GitLab CI. • Operations: observability and incident diagnosis. • Real use of AI-assisted development in a production codebase: agentic workflows, context management, reviewing generated output as critically as a colleague's merge request. You have a view on where these tools pay off and where they create debt. • Experience means you can say why you chose an approach, what you rejected, and what it will cost in six months. ### Bonus skills • Java. • Knowledge of the CLM/PKI (X.509 model) and CMDB domains. • Knowledge and hands-on handling of provider authentication schemes: OAuth2, mTLS, API keys. • Secure coding practices and application security. • Experience in a startup or deeptech environment. ### Benefits ### The team you'll be joining You will join a team of six engineers who own their features across the whole stack, inside our 15-person R&D department, working closely with Product and QA. You will report to the Head of Engineering and collaborate with other departments to build the backend services and interfaces our clients depend on. ### Our recruitment process 1. **Initial discussion** with our HR team to explore your background and motivations. 2. **Technical interview** with a developer: a live coding session of 1 to 1.5 hours. AI coding tools are required, not merely allowed. We are interested in how you direct and review them. No take-home assignment. 3. **Meeting with a manager** to ensure alignment with our company culture. 4. If successful, you'll receive a final offer! **Benefits** ### What's in it for you at CryptoNext • A stimulating work environment with cutting-edge technological challenges. • A competitive salary, aligned with our compensation philosophy. • A deep dive into the exciting world of post-quantum cryptography and cybersecurity. ## How to apply Apply on the job page, https://francedevjobs.com/jobs/cryptonext-security-senior-go-developer-integration-qne14wz: its Apply button opens the employer's own application page. ## More jobs from CryptoNext Security - [Senior Fullstack Engineer (TypeScript)](https://francedevjobs.com/jobs/cryptonext-security-senior-fullstack-engineer-typescript-oce7adw): CryptoNext Security, Paris, France. On-site. Posted 10 August 2026.