This is a high-impact, high-autonomy role; we are looking for a senior backend engineer to take the reins: own the architecture, raise the technical bar, and keep a system that handles business-critical call traffic reliable and fast.
You’ll work mainly on our core telephony service — an async FastAPI application following Domain-Driven Design, progressively migrating a legacy codebase toward a clean, well-specified architecture.
- Own the architecture and technical direction of the telephony backend, and drive the ongoing migration from legacy code to our DDD architecture.
- Design and build reliable, event-driven services: call tracking, scheduling, external event consumption, and provider integrations (telephony providers, Salesforce Pub/Sub).
- Write robust async Python (FastAPI, SQLAlchemy) with strong typing, full test coverage, and clear specifications.
- Make and document the hard technical calls — data modeling, throttling, retries, failure handling — pragmatically weighing trade-offs on a system where downtime means lost calls.
- Leverage AI tooling (Claude Code, Cursor, AI agents) to ship faster and better, and define how the team adopts AI responsibly and within our usage and security guidelines.
- Set the engineering standard: code reviews, mentoring, and lifting the team’s practices around testing, observability, and CI/CD.
- Collaborate closely with Product, Ops and other engineering teams to turn business needs into solid technical solutions.
- Own your work end-to-end — from design through autonomous deployment and monitoring in production.
- 8+ years of backend software engineering, with deep expertise in Python. Telephony, real-time systems or CTI integration experience is a plus.
- Strong with our stack or close equivalents: FastAPI (or Django/Flask), async SQLAlchemy / PostgreSQL, Redis, message queues, AWS.
- An AI-powered engineer — you use AI coding assistants and agents fluently as part of your daily workflow, and you know how to apply them responsibly and in compliance with usage, security and data-handling rules. This is a top priority for us.
- Proven track record designing and operating business-critical production backend services at scale — async, event-driven, integration-heavy systems where reliability is non-negotiable.
- Pragmatic by nature: you make sound, trade-off-driven decisions, ship the right thing rather than the perfect thing, and know when to optimize and when to keep it simple.
- Solid grasp of software architecture (DDD a strong plus), clean code, and rigorous testing — you treat tests, types and specs as part of the job, not an afterthought.
- Experience mentoring engineers and raising team standards.
- Fluent in English, working French is a plus.
