SDK Engineer - JavaScript in Brazil at Jobgether

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a SDK Engineer - JavaScript based in Brazil.

This role offers the opportunity to build developer tools that power modern applications and enable seamless interaction with backend platforms.
You will own critical JavaScript and TypeScript SDK experiences used by a large global developer community.
The position combines software engineering excellence, API design, open-source collaboration, and developer experience.
You will work on libraries that impact millions of developers while shaping how users interact with complex technologies.
The ideal candidate enjoys solving challenging technical problems, designing intuitive developer experiences, and working in an async, distributed environment.
This is a highly autonomous role where your decisions will influence public APIs, documentation, and the future evolution of developer tooling.

• Build, maintain, and evolve JavaScript and TypeScript SDKs that provide reliable and intuitive access to platform capabilities.
• Design and implement new SDK features by identifying developer needs, proposing solutions, and delivering impactful improvements.
• Work in public repositories by managing issues, reviewing external contributions, maintaining release processes, and supporting open-source collaboration.
• Own the developer experience around TypeScript types, ensuring accurate autocomplete, type inference, and seamless integration into real-world applications.
• Ensure SDK compatibility across multiple environments, including Node.js, browsers, Deno, Bun, Cloudflare Workers, React Native, and other modern runtimes.
• Develop and improve realtime functionality, including WebSocket connections, reconnection strategies, subscriptions, and presence features.
• Collaborate with platform teams to ensure SDKs remain aligned with backend capabilities, updates, and product changes.
• Create technical documentation, RFCs, migration guides, release notes, and developer resources that make adoption easier.
• Improve SDK usability for AI-powered coding tools and modern developer workflows.
• Maintain high engineering standards through testing, automation, code reviews, and thoughtful API evolution.
• Communicate technical decisions clearly and contribute to a culture of transparency, autonomy, and continuous improvement.

• Expert-level experience with TypeScript and JavaScript, including advanced knowledge of generics, conditional types, mapped types, and type system design.
• Proven experience building or maintaining published libraries, SDKs, or developer-facing platforms with external users.
• Strong understanding of open-source development practices, including issue management, pull request reviews, release workflows, changelogs, and semantic versioning.
• Experience with npm packaging, including ESM/CJS builds, export maps, module resolution, and package publishing best practices.
• Strong testing mindset with experience creating unit tests, type-level tests, end-to-end tests, and regression coverage.
• Experience designing and maintaining public APIs where backward compatibility and developer experience are critical.
• Excellent written communication skills with the ability to create clear documentation, technical proposals, and user-facing explanations.
• Ability to work independently, identify important problems, prioritize effectively, and deliver solutions in an ambiguous environment.
• Experience collaborating with globally distributed teams and working effectively in async-first environments.
• Strong problem-solving skills and enthusiasm for building tools that solve real challenges for developers.
• Ability to communicate technical concepts clearly with both technical and non-technical audiences.

• Fully remote work environment with the flexibility to work from anywhere.
• Global team culture with asynchronous workflows and high autonomy.
• Equity ownership opportunity through an employee stock option program.
• Technology allowance to help create an ideal home working setup.
• Health insurance coverage for employees and support for dependents.
• Annual company off-sites for collaboration, connection, and team building.
• Flexible schedule focused on outcomes and trust.
• Annual professional development budget for courses, books, conferences, and learning resources.
• Opportunity to contribute to open-source projects used by a global developer community.