Sr Software Engineer
Confirmed on the employer's own hiring board on Oct 23, 2026. First seen by Alion on Oct 2, 2026. Sinch scores A on the Alion truth index.
Description
Sinch is pioneering the way the world communicates. More than 150,000 businesses - including Google, Uber, PayPal, Visa, Tinder, and many others - rely on Sinch’s Customer Communications Cloud to power engaging customer experiences through mobile messaging, voice, and email.
Whether you need to verify users or craft omnichannel campaigns, Sinch makes it easy. Our AI-infused Super Network, APIs, and applications ensure you can connect with your customers reliably and securely, at every step of their journey.
At Sinch we “Dream Big”, “Win Together”, “Keep it simple”, and “Make it Happen”. These values are our foundation!
The Role
Our Intelligence team owns the AI at the core of Sinch’s conversational products: the systems that decide what a conversation means and where it goes next, and the assistants our customers use to configure those products. We build and operate the intelligence layer behind Agentic Orchestration - conversation routing through intent classification, retrieval-augmented generation and runtime conversation understanding, plus product assistants and copilots. We own these from first prototype through production, and they carry real conversations at real volume.
As a Senior Software Engineer, you will sit with our AI engineers and own the backend where the product meets the platform: durable orchestration, service boundaries, state, and how the system behaves once it is live. You will join a team of six - three senior AI engineers and an MLOps/DevOps engineer, led by our Tech Lead & Engineering Manager and our Product Manager. As you grow into the domain, you will also take on AI engineering work alongside the team. We use AI on purpose across discovery, development, review and incidents, and you will help shape that way of working. This is a hybrid role with expectations to work from our Madrid office every quarter.
What You Will Do
- Shape how our conversation-routing and product-assistant services plug into the rest of Sinch: Agentic Orchestration, neighbouring product APIs, and identity.
- Build the backend behind those services: APIs, persistence, and orchestration of multi-step AI workloads - durable workflows, retries, and state that survive a process restart.
- Lead code reviews, technical discussions, and knowledge-sharing sessions.
- Mentor and be mentored by other engineers, and help keep a culture rooted in the team’s values.
- Carry production through on-call rotations and incident response.
- Invest in system health: test coverage, technical debt, and how we operate.
Help evolve how the team builds with AI: the tools, guardrails, and shared practices.
What We Are Looking For
- 5+ years of professional software engineering experience.
- Strong proficiency in Python and Node.js/TypeScript.
- Experience with real-time systems: streaming APIs (SSE or WebSocket) and event-driven architectures.
- Hands-on experience with distributed systems and microservices, including state management across replicas (e.g. etcd, Redis).
- Experience building RESTful APIs and event-driven systems, ideally with Kafka.
- Hands-on experience with durable workflow orchestration, ideally Temporal (long-running workflows, activities, retries, concurrency across workers).
- Solid experience with complex cloud infrastructure, ideally GCP and/or AWS.
- Working knowledge of MongoDB or similar document databases.
- Strong system design fundamentals: scalability, latency, failover, and trade-offs.
- Production experience with AI, LLMs, or agents, and a working grasp of AI engineering concepts (RAG, tool use, agent patterns, evaluation, guardrails, LLM observability), with the willingness to go deeper.
- Active use of AI in your own engineering work, with full accountability for what you ship.
Clear communication in English, written and spoken, and comfort working in a distributed, cross-functional team.
Nice to have
- Experience with conversational AI, chatbot or voicebot platforms, or NLP/NLU pipelines.
- Experience with Docker and Kubernetes.
- Familiarity with identity management (OAuth/OIDC).
Experience in a CPaaS, scale-up, or fast-growth product company.
OUR HIRING PROCESS
We are committed to ensuring a recruitment process that is fair, objective, consistent, and inclusive. Our approach includes structured, competency-based interviews designed to evaluate your skills, experience, and qualifications relevant to the role. At times, we may include a data-driven assessment to enhance our hiring success and identify candidates likely to excel.
We believe in a two-way process and encourage you to ask questions throughout the journey. If this role isn’t what you’re looking for, please explore the other opportunities listed on our career page: https://www.sinch.com/careers/. No matter who you are, we hope you find an exciting path forward - hopefully with us!
The pay range for this role per year is 70,000 - 90,000 Euros depending on skills and experience.
- ed on our career page:https://www.sinch.com/careers/. No matter