Senior JavaScript Platform Engineer

5 Days ago • 6 Years + • $145,000 PA - $180,000 PA

Job Summary

Job Description

The Senior JavaScript Platform Engineer will design and ship a production-ready JavaScript SDK to collect data from customer websites for e-commerce and user behavior events, similar to Google Tag Manager or Segment. Responsibilities include developing the JavaScript library for user behavior collection in the browser, loader/bootstrap code, runtime APIs, plugin architecture, performance optimization, security hardening, and telemetry implementation. The engineer will also build consent-aware logic, utilize AI agents, and collaborate with product and API teams. The role involves creating developer-friendly documentation and monitoring SDK usage for iteration based on developer needs.

Must have:

6+ years of experience building JavaScript libraries.
Deep understanding of browser privacy technologies.
Strong performance optimization skills (async loaders, tree-shaking).
Exposure to edge runtimes (Cloudflare Workers, Fastly, AWS Lambda) or Node experience.
Proven experience with telemetry and feature-flag systems.

Perks:

Health & wellness
Equity

4 skills required

4 skills required for this role

Add these skills to join the top 1% applicants for this job

javascript

typescript

aws

bootstrap

Job Details

Attentive® is the AI-powered mobile marketing platform transforming the way brands personalize consumer engagement. Attentive enables marketers to craft tailored journeys for every subscriber, driving higher recurring revenue and maximizing campaign performance. Activating real-time data from multiple channels and advanced AI, the platform personalizes content, tone, and timing to deliver 1:1 messages that truly resonate.

With a top-rated customer success team recognized on G2, Attentive partners with marketers to provide strategic guidance and optimize SMS and email campaigns. Trusted by leading global brands like Neiman Marcus, Samsung, Wayfair, and Dyson, Attentive ensures enterprise-grade compliance and deliverability, supporting trillions of interactions across more than 70 industries. To learn more or request a demo, visit www.attentive.com or follow us on LinkedIn, X (formerly Twitter), or Instagram.

Attentive’s growth has been recognized by Deloitte’s Fast 500, Linkedin’s Top Startups and Forbes Cloud 100 all thanks to the hard work from our global employees!

About the Role

We’re looking for an engineer who loves the plumbing of the web—someone who can design and ship a production‑ready JavaScript SDK that can be embedded on customer sites driving data collection of ecommerce and user behavior events. Think Google Tag Manager‑level loader logic and Segment‑style event pipelines—all delivered through a single <script> tag. Collecting high-quality first-party data is foundational to powering the personalized marketing engine at the core of Attentive’s platform—enabling brands to deliver timely, relevant messages that drive engagement and revenue.

You’ll be part of the team that owns several critical components of Attentive’s data collection platform:

• JavaScript library development of Attentive’s Tag to collect user behaviors in browser

• Loader/bootstrap code, runtime APIs, plugin architecture, performance / bundle‑size budgets, security hardening, and robust telemetry

• SDK enabling custom-coded on-site data collection

• Build consent‑aware logic that adapts to Safari ITP, Firefox ETP, Chrome Privacy Sandbox, and shifting state‑level regulations.

• Utilizing emerging technologies such as AI Agents to customize data collection on a per-customer basis

What You’ll Accomplish

Design, build, and maintain SDKs in JavaScript (and possibly TypeScript) to interface with our platform’s APIs
Work closely with product and API teams to align SDK development with platform features
Optimize SDKs for performance, reliability, and ease of integration
Create developer-friendly documentation, examples, and guides
Monitor usage, gather feedback, and iterate based on developer needs

Your Expertise

6+ years building JavaScript libraries or tag managers consumed by external sites.
Deep understanding of browser privacy tech: ITP, ETP, Privacy Sandbox, partitioned cookies, Storage Access API.
Strong performance chops—async loaders, Web Workers, tree‑shaking.
Exposure to edge runtimes (Cloudflare Workers, Fastly, AWS Lambda) or Node experience.
Proven track record shipping telemetry / feature‑flag systems that can flip behavior instantly.

You'll get competitive perks and benefits, from health & wellness to equity, to help you bring your best self to work.

For US based applicants:

- The US base salary range for this full-time position is $145,000 - $180,000 annually + equity + benefits

- Equity is a substantial part of the total compensation package

- Our salary ranges are determined by role, level and location

#LI-SM1

Attentive Company Values

Default to Action - Move swiftly and with purpose

Be One Unstoppable Team - Rally as each other’s champions

Champion the Customer - Our success is defined by our customers' success

Act Like an Owner - Take responsibility for Attentive’s success

Learn more about AWAKE, Attentive’s collective of employee resource groups.

If you do not meet all the requirements listed here, we still encourage you to apply! No job description is perfect, and we may also have another opportunity that closely matches your skills and experience.

At Attentive, we know that our Company's strength lies in the diversity of our employees. Attentive is an Equal Opportunity Employer and we welcome applicants from all backgrounds. Our policy is to provide equal employment opportunities for all employees, applicants and covered individuals regardless of protected characteristics. We prioritize and maintain a fair, inclusive and equitable workplace free from discrimination, harassment, and retaliation. Attentive is also committed to providing reasonable accommodations for candidates with disabilities. If you need any assistance or reasonable accommodations, please let your recruiter know.