Sinch

Job Description

About Sinch

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!

About the role

As a Software Engineer in our Developer Experience (DX) organization, you will play a key role in shaping how Sinch builds, exposes, and enables AI agents for both internal and external use.

This role sits at the intersection of SDK development, developer tooling, and emerging agentic platforms. You will start by contributing to our Python SDK, which is a core touchpoint for external developers integrating with Sinch. This initial focus will help you build deep familiarity with our APIs, products, and developer workflows.

Building on that foundation, you will progressively work on Python-based AI agents and agent-based integrations that Sinch exposes to customers and partners, enabling new ways to automate and orchestrate communications using agentic frameworks and platforms.

This is a developer-facing platform role, not a traditional backend product position. Your work directly impacts how easy, consistent, and enjoyable it is to build on top of Sinch.

This role is open to candidates based in Spain, from our offices in Madrid.

What you will do

As a Software Engineer, you will:

SDK foundation (initial focus)

• Contribute to the design, development, and maintenance of Sinch’s Python SDK.
• Ensure high-quality API coverage, consistency, and usability across the SDK.
• Improve developer ergonomics, documentation, examples, and testing.
• Collaborate with other SDK engineers across languages to maintain alignment and consistency.

AI agents & developer tooling (progressive focus)

• Design and implement AI agents in Python that integrate with Sinch APIs and services.
• Leverage and evaluate agent frameworks such as LangChain, ADK, or other emerging tools, and help define which ones are relevant for Sinch use cases.
• Expose agents in a way that is composable, secure, and developer-friendly.
• Collaborate closely with Product Management, MCP engineers, SDK teams, and documentation teams to ensure agents fit naturally into the overall Sinch developer experience.
• Contribute to defining patterns, guardrails, and best practices for agent design, observability, and safety.
• Collect feedback from internal usage and early customer integrations to continuously improve agent quality and usability.
• Participate in architectural discussions around agentic systems, AI tooling, and developer-facing platforms.

Requirements

• 5+ years of professional software development experience, with strong proficiency in Python.
• Experience designing and maintaining SDKs, libraries, or developer-facing tooling.
• Experience designing and building backend services, tools, or integrations.
• Practical experience building with REST APIs and external services.
• Strong interest in AI agents, developer tooling, and emerging AI frameworks.
• Ability to work effectively in environments with high ambiguity and evolving product definitions.
• Experience writing production-quality code with testing, logging, and observability in mind.
• Comfort collaborating across teams and supporting other engineers in adopting new tools or patterns.
• Fluent English, both written and spoken.

Nice to have

• Hands-on experience with LangChain, ADK, LlamaIndex, or similar agent frameworks.
• Experience exposing AI-powered tools, agents, or workflows to external users.
• Familiarity with automation or integration platforms.
• Experience working on developer-facing platforms, SDKs, or tooling.
• Experience working across multiple languages or SDK ecosystems (e.g. .NET, Java, Python).
• Exposure to multiple programming ecosystems beyond Python.

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!

Please send your CV in English language.