Senior Backend/Full Stack Engineer

You'll join Photon as a Senior Backend/Full Stack Engineer, working on the distributed messaging infrastructure that powers AI agents across iMessage, WhatsApp, Telegram, and beyond. You'll own complex systems from architecture to production, building the APIs and internal platforms that make Photon's infrastructure effortless to use. This role offers significant autonomy and direct influence over our technical direction and product.

What You'll Do

• Design and operate highly available backend services handling large-scale, real-time messaging workloads.
• Take end-to-end ownership of projects from problem definition through architecture, implementation, deployment, and ongoing operation.
• Build intuitive APIs, SDKs, and developer tools with thoughtful abstractions and attention to detail.
• Solve distributed systems challenges around reliability, concurrency, fault tolerance, and message delivery.
• Contribute across the stack—backend services, developer dashboards, internal tooling, and infrastructure—wherever the problem requires it.
• Evaluate technical tradeoffs and make pragmatic decisions that balance engineering quality with execution speed.
• Use AI coding agents to increase engineering leverage while maintaining deep understanding of code and operational consequences.
• Participate in architecture discussions, code reviews, and incident analysis to continuously raise our engineering standards.

What We're Looking For

• 3+ years of professional software engineering experience, including substantial work building and operating production backend systems.
• Strong proficiency in TypeScript/Node.js, plus experience in at least one additional backend language like Go, Rust, or Swift.
• Solid understanding of distributed systems, concurrency, networking, databases, and API design.
• Hands-on experience with PostgreSQL, Redis or other NoSQL systems, AWS, Kubernetes, and cloud infrastructure.
• Proven ability to independently design, implement, deploy, and maintain complex systems.
• Strong engineering judgment and the ability to critically evaluate AI-generated code.
• Experience building high-availability services with observability, incident response, and performance optimization.
• Fluency in Mandarin.

Compensation & Benefits

$100K–$250K base salary plus meaningful equity. H-1B sponsorship, OPT, and CPT support available.

Location

On-site in San Francisco, CA.