Senior Fullstack SDK Engineer
Customer.io3 months ago
Remote, AmericasSenior
Base Salary
$150k - $200k/yr
Responsibilities
- Build and evolve Customer.io SDKs across Android, iOS, Node, and Go, plus the developer tools that support them.
- Lead SDK initiatives end to end by setting technical direction, writing code, managing releases, and owning outcomes.
- Improve SDK delivery infrastructure, automated testing, versioning, publishing, and release processes.
- Partner with product and design to turn loosely defined goals into effective developer experiences.
- Use AI agents to make multi-file changes across unfamiliar codebases and languages, including scoping work, writing prompts, and verifying results.
- Understand the needs of engineers integrating with the SDKs and occasionally engage directly with customers.
Requirements
- Expert-level competency in at least one established programming language, with strong software design and API design fundamentals.
- Experience building and evolving mature, production-quality software and understanding how systems fit together and are consumed by other developers.
- Exceptional fluency with current LLMs and agentic coding tools such as Claude, Cursor, and Codex.
- Ability to operate autonomously in ambiguous environments and drive implementation without close direction.
- Strong written and verbal communication skills, including the ability to explain technical decisions and tradeoffs.
- Ability to work effectively across multiple languages and technology stacks; prior experience with every supported language is not required.
- Experience with external-facing SDKs, APIs, developer tools, CI, testing, versioning, release infrastructure, or forward-deployed engineering is preferred.
Benefits
- 100% coverage of medical, dental, vision, mental health, and supplemental insurance premiums for employees and their families.
- 16 weeks of paid parental leave.
- Unlimited paid time off.
- Remote work and wellness stipends.
- Professional development budget.
- Remote work support is provided, with virtual interviews conducted via Zoom.
Categories
About Customer.io
Customer.io builds a customer engagement and messaging platform for product and marketing teams to create automated, data-driven campaigns across email, SMS, push, and in-app channels. It operates as a SaaS subscription with integrations and real-time behavioral data routing. Founded in 2012 and headquartered in Portland, Oregon, it is used by more than 9,000 companies and delivers billions of messages for startups and global brands.