Senior Full Stack Engineer — TypeScript / Next.js (100%, m/f/d)

LeaseTeq AG; Berlin; On-site; EUR 70,000 - 90,000; Full time

Benefits offered by this job

Hybrid Berlin office (2–3 days)

€70k–€90k gross annually

Annual bonus 10–15%

Health insurance options

Pension scheme

AI tooling budget

Modern Apple devices

Job summary

United States Digital Space LLC in Berlin is seeking an experienced full‑stack engineer to own the German market on our customer‑facing platform. You will design the digital application journey, ensure German compliance, and collaborate with teams across Switzerland and Austria.

You will implement multi‑step onboarding, KYC flows, and field mappings to CRM and Flowable, write API layers, and drive end‑to‑end tests. Fluency in German and English is required, with a strong fintech background.

Qualifications

• 6+ years of full-stack TS engineering with React/Next.js production work.
• Fintech experience on regulated financial products is mandatory.
• Proven ownership of complex multi-step onboarding or application flows.

Responsibilities

• Own the German market on the customer-facing platform, including credit and compliance rules.
• Design and build the multi-step onboarding journey with validation and resumable state.
• Build and maintain customer, dealer, and operations portals and mapping logic.
• Write API layers behind the journey and ensure end-to-end testing coverage.
• Collaborate with Berlin backend and Jakarta platform engineers on cross-market journeys.

Skills

Full-stack TS

React

Next.js App Router

Server components

Fintech experience

Onboarding flow

PostgreSQL/Prisma

Zustand

TanStack Query

Formik

React Hook Form

Zod

Playwright/Cypress

AI-first mindset

Regulatory knowledge

Internationalisation

German & English

Tools

Flowable BPM

PostgreSQL

Prisma

Formik

React Hook Form

Zod

Playwright

Cypress

Job description

Your missionYou are the architect and builder of the customer-facing side of the the company platform in Berlin, and the owner of our German market on it. You design the digital application journey and the portals that carry real customers, dealers and operations teams at production scale, and you make sure German credit rules, compliance requirements and dealer flows are represented correctly in a platform that also serves Switzerland and Austria. You work in a small, senior team where your decisions have direct product impact, and you naturally bring AI tooling into your daily engineering workflow without being asked.

What you will do

• Own the German market on our customer-facing platform: credit and compliance requirements, dealer flows, German copy, and the acceptance criteria that make them verifiable
• Design and build the digital application journey — multi-step forms, validation, resumable state, document upload, KYC steps and the unhappy paths users actually hit
• Build and maintain the customer, dealer and operations portals, including the operations board and the logic that decides where a case belongs
• Write the use‑case and API layers behind the journey to our clean‑architecture standard — this is a full‑stack role, not a UI role
• Own field‑level mapping into the CRM and the Flowable‑based process engine — beneficial ownership, source of funds, origin of income, additional persons — where a wrong key is a compliance defect, not a cosmetic one
• Author specification‑driven change proposals, and act as the named human approver for journey and mapping changes in the German market
• Grow end‑to‑end test coverage on the critical journeys: coverage is what licenses autonomous agent work in a module
• Work with our Berlin backend team on the seam between the orchestration core and the customer‑facing platform, and with our Jakarta platform engineers who own the journey across all three markets
• Communicate clearly in German and English with engineering peers and business stakeholders

Your profile

• 6+ years of full‑stack TypeScript engineering, with recent production work in React and Next.js App Router — server components, server actions and route handlers, with a clear grasp of what runs where — is mandatory
• Fintech experience is mandatory: production work on a regulated financial product — leasing, lending, banking, payments or insurance — where money moved and a regulator could ask why
• Proven ownership of a complex multi‑step onboarding or application flow is mandatory: validation strategy, partial persistence and resumption, conditional branching by market or product, document upload
• Real backend capability: use cases, repository implementations, API handlers and PostgreSQL / Prisma queries — roughly a 60/40 split toward the frontend, not 90/10
• State and data‑fetching maturity (Zustand or equivalent, TanStack Query) and confident use of form and schema tooling (Formik or React Hook Form with Zod), including server‑side validation parity
• End‑to‑end testing with Playwright or Cypress on flows that are slow, stateful and integration‑dependent
• AI‑first engineering mindset: daily use of coding assistants and agents on production work, and the ability to write a change specification precise enough that an agent implements it correctly and a reviewer can verify that it did
• Working understanding of the German regulatory environment for consumer credit or asset finance — BaFin‑supervised context, AML/KYC obligations, consumer‑credit disclosure — is a strong plus
• Internationalisation as a habit — no hard‑coded strings, and awareness of what four locales do to layout and copy
• Fluent German and English

Why us?

• Founding‑team‑level ownership of our customer‑facing platform and of the German market on it
• Direct collaboration with the CTO and the founders, including regular visits to our Swiss headquarters
• A genuinely AI‑first process, not a slogan: specification‑driven delivery where agents execute approved changes and humans own scope, architecture, regulatory and release decisions
• Hybrid setup with 2‑3 days per week in our coworking office in Berlin (WeWork, Stresemannstrasse)
• Competitive and fair salary: €70,000 - €90,000 gross per year, depending on experience and impact
• 10–15% annual bonus tied to company performance and clear OKRs
• Tax‑free monthly benefit allowance of €50 that you can use for what you personally value
• Sustainable mobility budget: subsidy for e‑bike leasing and app‑based car sharing for occasional trips
• Additional health insurance options, including enhanced coverage for dental and vision care
• Company‑supported pension scheme with employer contributions on top of the statutory system
• Employer‑funded disability coverage starting from day one of employment
• Dedicated AI tooling budget (e.g. Cursor, Claude API) so you can experiment and move fast
• Modern Apple devices
• Our remote policy promises 4 weeks & worldwide

About the company

the company builds the orchestration brain for mid‑market car leasing and asset finance in the DACH region. Our platform automates the full contract lifecycle – from origination and credit decision through to end‑of‑term – using Flowable BPM as the core process engine on a modern, event‑driven micro‑services architecture, with a Next.js / TypeScript platform serving our customer, dealer and operations portals in four languages across Switzerland, Germany and Austria. We are an AI‑first engineering team: agents, intelligent workflows and LLM‑augmented automation are how we build today, not items on a future roadmap. From our base in Switzerland, our subsidiaries in Austria and Germany and our engineering team in Jakarta, you join a small, senior team where your decisions have visible impact on customers, partners and the future of our product.

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