Senior Software Engineer (JVM & Kotlin)

Location: Hybrid 2 days per week, based in Warsaw

Salary for Senior (IC3):

• UoP (Contract of Employment) = 23,000 - 31,000 PLN per month gross

• B2B = 27,000 - 37,000 PLN per month net +VAT

About hyperexponential (hx)

At hyperexponential, we’re building the AI-powered platform that enables the world’s most critical decisions in a $7 trillion industry, which risks to take, and how to price them. These are the decisions that shape real-world outcomes: whether rockets successfully launch into space, autonomous vehicles make it to market, or communities recover after major storms.

Until now, insurers have been making billion-dollar decisions using outdated tools. We’re changing that. Our platform brings together data, AI, and human expertise to give insurers the fastest path from submission to decision - helping them move faster, act smarter, and take on more risk with confidence.

Backed by a16z, Highland Europe, and Battery Ventures, we’re scaling globally - already trusted by nearly 50 of the world’s largest insurers, with zero churn and billions in premiums flowing through hx.

What began as a single product in one market has rapidly evolved into a multi-product, multi-territory platform powering every stage of pricing and underwriting. AI is at the core of what we do - from building the world’s first domain-specific AI peer programmer for insurance (think GitHub Copilot with a PhD in actuarial science) to shaping agentic workflows that reinvent how this industry operates.

What makes hx different is the people who build it. Here, impact isn’t tied to title or tenure; it’s defined by the challenges you take on and the discipline you bring. Surrounded by peers who stretch you, you’ll do the best, hardest work of your life in a company engineered to endure.

If that sounds like you, join us in building what comes next.

About Your Role

Engineering at hx tackles complexity that matters. Submission Triage is one of our most strategically important product areas, transforming how the world's largest insurers handle inbound submissions. Where carriers once relied on slow, manual processes to sort through documents, emails, and attachments, we're building AI-powered workflows that convert chaos into clarity - enabling underwriters to focus on the risks that matter most.

The Triage team sits at the intersection of ambitious product vision and technical depth. You'll work alongside Product, AI specialists, and client-facing teams to architect systems that ingest unstructured data from multiple channels, apply intelligent triage logic, and deliver actionable insights at speed. This isn't incremental improvement - it's reimagining how submission intake works in a market where every hour counts.

As a Senior Engineer, you'll own meaningful architecture decisions, shape product direction through engineering judgement, and see your work deployed into production environments at global insurers within weeks. Success here is measured in faster quote turnarounds, reduced manual effort, and revenue growth for one of hx's highest-priority products.

Check out our Engineering Candidate Hub for a behind the scenes look at the team you would be joining!

Your Senior Engineer Responsibilities

• Design and build scalable backend architecture for Triage that handles diverse submission formats (Excel, PDF, Word, images, email) and converts unstructured data into structured, actionable fields with measurable improvements in processing speed and accuracy.

• Partner directly with Product and clients to translate underwriting workflows into technical requirements, turning ambiguous problems into concrete system designs that demonstrably reduce manual triage time.

• Architect data pipelines that integrate AI-powered extraction with deterministic business logic, ensuring reliability and explainability while accelerating time-to-value for new client deployments.

• Drive technical decisions around system modularity, API design, and multi-tenant configuration strategies that support diverse client needs without creating unmaintainable complexity or slowing iteration speed.

• Collaborate with AI teams to identify where machine learning adds genuine value versus where traditional logic performs better, optimising for both accuracy and client trust in production environments.

• Establish patterns and architectural standards for a strategically critical product area, raising engineering quality while maintaining the velocity needed to respond to market demands and competitive pressures.

What You Need To Be Successful

• Built and scaled production backend systems on the JVM (Java, Kotlin, or similar) that handled complex data processing or workflow orchestration, delivering measurable improvements in throughput, latency, or system reliability.

• Designed architectures for systems that ingested unstructured or semi-structured inputs and transformed them into structured outputs, demonstrating strong judgement around data validation, error handling, and pipeline resilience.

• Worked closely with product teams or clients to shape technical solutions based on real-world workflows, translating user needs into engineering decisions that balanced delivery speed with long-term maintainability.

• Delivered features in ambiguous problem spaces where requirements evolved rapidly, showing ownership over outcomes rather than simply executing pre-defined tickets or specifications.

• Made pragmatic trade-offs between technical excellence and time-to-market, shipping solutions that were good enough to validate hypotheses while maintaining the quality standards needed for production reliability.

• Collaborated with cross-functional teams (product, design, AI, or customer success) to drive alignment around technical direction, demonstrating strong communication skills and an ability to influence without formal authority.

Interview Process

1. Initial screening with Talent team to kick things off (30 minutes)

2. Manager Interview (60 minutes)

3. Technical Assessment - Code Review & Systems Design (120 minutes)

4. Values Interview (60 minutes)

5. We offer!

How hx Warsaw Works

At hyperexponential, we believe in a balance between remote work, and building relationships across teams and locations. You’ll have your main office in Warsaw, 2 days a week, with also ability to travel to London HQ to meet the wider team. International travel will be much less frequent, perhaps 2-3 times a year.

Warsaw HQ was established in 2023, quickly hiring our first handful of high-calibre engineers. Fast-forward to today in 2025, there are 50+ in Warsaw and surrounding cities who travel for the collaborative environment.

On Wednesdays you’ll often find Warsaw HQ organising team lunch paid by hx, getting drinks after hours. The office is also dog-friendly, so feel free to bring yours along!

What Your Offer Could Look Like

B2B

• Share Options at a highly successful Series B company

• 25 days of non-working + Polish bank holidays

• £5,000 GBP budget for Learning & Development

• Mental Health Support and Therapy via Spectrum Life

• Optional for you: access to Private Healthcare via Luxmed + Multisport (fully funded by yourself as B2B Contractor)

• Top-spec laptop (MacOS or Windows)

Contract of Employment (UoP)

• Share Options at a highly successful Series B company

• £5,000 GBP budget for Learning & Development

• 26 days of holiday + Polish bank holidays

• Company pension

• Company Sick Pay for 10 days at 100% salary

• Mental Health Support and Therapy via Spectrum Life

• Monthly Wellbeing allowance via Juno

• Private Healthcare Insurance via Luxmed

• Multisport - Classic level

• Top-spec work equipment (MacOS, Windows + additional monitors, mechanical keyboards etc)