# Senior Backend Engineer

**Company:** [hyperexponential](https://hotfix.jobs/companies/hyperexponential)
**Location:** Warsaw, Poland
**Role:** Backend Engineering
**Experience:** 5+ years
**Skills:** Kotlin, Java, Jvm, Backend Systems, System Design, APIs, Domain Modeling, Persistence, Observability, Ai Coding Tools, Claude, Workflow Systems, Agent-Assisted Workflows, Frontend Development, Insurance Underwriting
**Posted:** 2026-08-19

> Build and operate backend services for an AI-native underwriting platform, shaping architecture, domain models, and agent-assisted workflows. The role requires strong JVM backend experience, sound system-design judgment, ownership, and comfort solving ambiguous problems with customers and cross-functional teams.

## Job Description

## Responsibilities
- Design, build, and operate backend services in Kotlin or Java, owning them in production.
- Translate ambiguous underwriting problems into simple, reliable software.
- Shape architectural decisions across APIs, domain models, persistence, reliability, observability, and platform evolution.
- Build expertise in the underwriting domain and challenge requirements when appropriate.
- Design and build agent-assisted workflows, deciding where agents act, advise, or defer to humans.
- Use AI coding tools, including Claude, while remaining accountable for code quality, security, and correctness.
- Collaborate with frontend engineers, product partners, and client-facing teams.
- Give and receive direct feedback and help raise engineering standards.

## Requirements
- Strong professional experience building and operating backend systems in Kotlin, Java, or another JVM language.
- Experience with architecture and system design, including prioritizing near-term versus long-term decisions.
- Evidence of shipping software that solved a real customer or business problem, ideally with end-to-end ownership.
- Self-starting approach to identifying high-value problems.
- Clear communication with underwriters, executives, and engineers.
- Comfort working on ambiguous problems without established precedents.
- Responsible use of AI coding tools and critical evaluation of their output.
- Receptiveness to direct feedback.

## Nice-to-haves
- Experience in insurance, underwriting, or another complex regulated domain.
- Experience across both backend and frontend development.
- Experience building workflow, decision-support, or agent-assisted products.
- Experience working directly with enterprise clients.

## Compensation & Benefits
- Share options at a highly successful Series B company.
- 25 days of non-working leave plus Polish bank holidays.
- £5,000 GBP learning and development budget.
- Mental health support and therapy via Spectrum Life.
- Optional private healthcare via Luxmed and Multisport for B2B contractors, fully self-funded.
- Top-spec laptop with MacOS or Windows.

## Interview Process
- Talent team chat: 30 minutes.
- Manager interview: 60 minutes.
- Technical assessment, such as code review or system design: 120 minutes.
- Values interview with senior technical leadership: 60 minutes.

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