Software Engineer - Developer Experience SDK (Node.js)

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 how Sinch APIs are consumed across multiple programming languages.

Your primary focus will be the development and maintenance of Sinch’s Java SDK , one of our most widely used SDKs. Through this work, you will gain deep familiarity with Sinch APIs, products, and developer expectations.

In addition, you will be a core contributor to our SDK generation tooling , which is used to generate Java, Node.js, Python, and .NET SDKs from OpenAPI specifications. In this role, you will help scale SDK development across languages by implementing shared generation logic, templates, and conventions that other members in the SDK team rely on.

This is a developer-facing platform role with strong impact across the entire DX organization.

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

What you will do

As a Software Engineer, you will:

Be the primary developer on the SDK/library you are responsible for, through the whole development cycle: design, develop, and maintain a modern, user-friendly TypeScript SDK .
Work closely with your Developer Experience colleagues on SDK features and overall SDK consistency.
Ensure the SDK is well-documented, easy to use, and follows best practices for TypeScript and Node.js development.
Write clean, efficient, and maintainable TypeScript code, with a strong focus on developer experience.
Implement robust error handling, logging, and testing to ensure reliability.
Optimize SDK performance and usability, gathering feedback from internal and external developers.
Work with the documentation team to keep all documentation easy to read, test, and enriched with relevant examples.
Stay up to date with the latest Node.js, TypeScript, and ecosystem features and industry trends.

Requirements

5+ years of professional experience in TypeScript and Node.js development .
Strong understanding of REST API design and consumption .
Experience with npm package creation, versioning, and maintenance .
Knowledge of CI/CD pipelines and release workflows.
Familiarity with asynchronous programming patterns in JavaScript/TypeScript.
Comfort working in a role where developer experience, usability and API design quality are key success metrics.
Fluent English, both written and spoken.

Nice to have

Experience in SDK or library development is a strong plus.
Familiarity with modern TypeScript features and tooling.
Knowledge of OpenAPI specifications and API schema-driven development.
Knowledge of Python or .NET is an added value (to review other SDKs code).
Knowledge of Java and interest in expanding your skills in this area is very welcome.
Excellent problem-solving skills and attention to detail.
Ability to communicate clearly in both user documentation and code .

How you work

You care deeply about developer experience and API ergonomics.
You write code with the SDK consumer in mind, not just the compiler.
You have strong opinions about good SDK design, but you’re open to discussion and feedback.
You value clarity, consistency, and maintainability over cleverness.
You are comfortable working closely with other SDK engineers to align behavior and patterns across languages.
You enjoy improving existing codebases as much as building new features.

What we don’t expect

We don’t expect you to:

Be an expert in every SDK language we support.
Design SDK behavior in isolation: SDK design is a collaborative effort.
Chase the latest Node.js trends at the expense of stability and usability.
Write quick hacks or shortcuts that harm long-term maintainability.
Produce the perfect solutions from day one: iteration and improvement are part of the job.

Why this role matters

The TypeScript / Node.js SDK is an entry point for developers integrating with Sinch APIs. Your work will directly impact:

How quickly developers can integrate Sinch into their applications
How intuitive and trustworthy our APIs feel to JavaScript and Node.js developers
How consistent Sinch SDKs are across different programming languages
How developers perceive Sinch as a developer-first, API-driven platform

By improving the Node.js SDK, you are improving how a large part of the developer ecosystem experiences Sinch.

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.