Senior Backend Engineer

Who You Are We're looking for a Senior Backend Engineer who thrives in high-ownership environments and knows what it takes to build, ship, and operate distributed systems at scale, not just design them. You’ll help build and scale a product that relies on reliable, high-throughput backend services and strong operational maturity. This is a hands-on senior role: you will design, code, ship, operate, and continuously improve distributed systems in production. You're someone who has seen production fail, learned from it, and built better systems because of it. You care about observability, reliability, and code quality not as checkboxes but as craft. You're comfortable with ambiguity, collaborative by nature, and you raise the bar for the engineers around you. What you’ll do Design and implement distributed backend systems : services that are resilient, observable, and scalable (latency, throughput, reliability). Build event-driven and asynchronous architectures using queues, pub/sub, background workers, and idempotent processing. Own production reliability : performance tuning, incident response, on-call participation (if applicable), and systematic improvements (SLOs, error budgets, runbooks). Raise the engineering bar : lead by example in code quality, API design, testing strategy, and operational best practices. Deeply instrument services with logs, metrics, and traces; help standardize observability patterns across the platform. Partner with Product and other engineers to define success metrics, measure impact, and iterate quickly based on real usage. Mentor and guide : review designs and PRs, support other engineers, and shape long-term technical direction. Specifically, we’re looking for Senior experience (typically 8+ years) building and operating backend systems in production. Strong coding skills in Go (production-grade, not scripting). Distributed systems fundamentals : concurrency, backpressure, retries, idempotency, consistency tradeoffs, schema evolution, failure modes. Cloud and infrastructure maturity (AWS preferred): designing services with managed cloud components, scaling patterns, cost awareness. Kubernetes and Docker experience: containerized services, deployments, operational workflows. Observability expertise : traces, metrics, logs, dashboards, alerting, incident analysis (Datadog and/or OpenTelemetry experience is a plus). Databases : strong PostgreSQL skills (schema design, indexing, query tuning) plus comfort working with OpenSearch and modern data stores. Engineering rigor : testing strategies (unit, integration, contract), CI/CD hygiene, safe rollout patterns (feature flags, canaries, gradual releases). Bonus Experience with queueing and streaming systems (SQS, SNS, Kafka, Kinesis, RabbitMQ, Pub/Sub). Vector databases and retrieval patterns (pgvector, Pinecone, Weaviate, Milvus, Qdrant, OpenSearch vector). Redis, MongoDB (only if truly used and not just “resume keywords”). Terraform (or equivalent IaC), GitHub Actions (or similar CI/CD). Security basics for backend systems (authn/authz, secrets management, least privilege, threat-aware design). What success looks like Services that are easier to operate: clear SLOs, better alerts, faster incident resolution. Higher throughput and lower latency as usage grows. Stronger platform foundations: repeatable patterns for async processing, observability, and safe deployments. A team that levels up through your mentorship and technical leadership. Ideally, you are someone that Has previously worked in startups - comfortable navigating some uncertainty and high energy environments Enjoys the collaborative process with different roles to design, implement and iterate on possible ideas and solutions Is not a perfectionist but has a mindset of continuous, incremental improvements towards top-quality work Is great at communicating with engineers, product managers, and other team members Bonus: Worked in the SalesTech space Our Process We want to be mindful of your time while finding the right candidate for our team. No homework to do, only human interactions ! Our typical recruitment timelines looks like this: Screening call with Talent Acquisition (30 minutes) - to know more about you and go deeper about the role Technical fit call with CTO (30 minutes) - to get to know each other, know about your technical depth. Virtual Onsite Session : Coding Session (1 hour) : In this hands-on session, you'll pair with our engineers to solve a real-world problem, focusing on clean logic, maintainability, and how you think through edge cases in real-time. System Design Interview (1 hour) : We’ll dive into a whiteboard session to explore how you architect scalable systems, specifically looking at your ability to navigate technical trade-offs and balance performance with simplicity. Culture and Values Interview (30 minutes) : We’ll wrap up by exploring our core values and your working style to ensure our environment is one where you’ll feel energized, supported, and empowered to do your best work. Manager Interview (30 minutes) : This is a two-way conversation with your potential lead to discuss your career trajectory, how you navigate project ownership, and how we can support your growth within the team. If all goes well, we’ll then make you an offer ! What we offer Up to 100K€ package, depending on equity, profile and contract type Challenging and interesting work A place in our diverse team A healthy work environment (few meetings and “low touch” management) Fully-remote work within EU timezones (GMT +/- 3h) Stipend to set up your home office Yearly team events in Paris and offsite Health insurance and other benefits applicable to your place of residence, if contract of employment in France or elsewhere via Deel Employer of record Possibility to work as a freelancer