Full-Stack Senior Engineer @ fast-growing, mission-driven tech startup at Crosstie – Boston | Jobyssey

Compensation: $120k – $175k • 0.05% – 0.1%

Title: Full-Stack Senior Engineer

Location: Fully remote

Company overview Crosstie is a workflow platform for property and casualty (P&C) insurance claims and service. Our modular solutions help carriers, TPAs, and self-insured organizations automate work across FNOL, document processing, voice, claimant experience, claim intelligence, portals, loss control, and other operational workflows. Founded out of the Harvard Innovation Labs, Crosstie is backed by General Catalyst, MassMutual Ventures, and insurance industry veterans. The company has been in production for six years and serves organizations ranging from smaller claims teams to tier-1 carriers and multiple top-10 TPAs. Crosstie is profitable and entering its next stage of growth.

What we’re looking for: We're seeking a skilled Full-Stack Senior Engineer to join our team. In this role, you'll design and build cutting-edge user experiences and workflow automation tools. You'd be joining a small-ish team (~25 people), that moves fast, values excellence, collaboration, creative problem-solving, and has high expectations of one another. This position offers significant growth opportunities for someone who thrives in a fast-paced environment where your contributions will have a direct impact on our products and users.

What we expect from our engineers:

Product First - You care deeply about the people using our products and understand how your work fits into theirs. You build for the customer, not just the ticket.
Attention to Detail - You take pride in the quality of what you ship. Code review and QA aren't chores to you; they're how great software gets made.
Curiosity - You're always learning, and you never build something without first understanding the "why" behind it.
Ownership - You're accountable for what you deliver, from first commit through production. If it breaks, you're the first to know and the first to fix it.

Responsibilities:

Rapidly building and iterating on new features using a primarily TypeScript / React / Express / PostgreSQL stack
Developing scalable solutions that can transition smoothly from concept to production
Building agentic features that automate complex insurance workflows

Must-have Qualifications:

Strong fullstack engineering skills (frontend, backend, database, infrastructure)
Experience building and integrating AI agents into applications
Experience with agent-first software development (Claude Code, Codex, etc.)
Experience with modern multitenant infrastructure in the cloud (AWS preferred)
Ability to rapidly prototype solutions while considering production scalability requirements
Self-starter, motivated, and organized
Strong cross-team communication skills

Nice-to-have Qualifications:

You’ve taken a product from 0 to 1 (i.e., idea to customers)
Experience with microservice architecture
Experience in a regulated domain such as insurance, healthcare, finance, etc.
Experience with audio/voice-related solutions

What We Offer:

Opportunity to work with a passionate, collaborative, and innovative team
A culture that values creativity, curiosity, and professional growth
Competitive compensation package and flexible remote work environment
Direct impact on products that help improve people's physical and financial wellbeing

To apply: Please submit your application here on Wellfound, and additionally email 'info at crosstietech.com' with your resume and why you think you'd be a great fit.

Thanks,

Sean (Co-founder)

p.s. Please no recruiters, no candidates not authorized to work in the U.S., and no contractors. We also ask that you please don't reach out directly to a member of our team about this opportunity over email, phone, or LinkedIn. Sorry, but these messages/submissions will not be replied to.

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