Fullstack Developer (m/w/d)

About us Buying, renovating, or modernizing a house – for most people, the biggest project of their life. And yet most people navigate it alone through a jungle of subsidy applications, energy certificates, and contractor costs. Very few can afford an architect who truly accompanies them through the process. That's exactly what we're changing. On Mein Haus Digital, private homeowners book concrete services – floor plans, energy certificates, cost estimates, subsidy consulting – guided by our experts and supported by software. Next up is an interactive editor for independently planning renovation projects, later with AI as a sparring partner. The long-term goal: a digital architect standing by every homeowner's side. We're an early-stage startup so: you're joining early enough to have real impact and help shape our infrastructure and deployment processes from the ground up, rather than just maintaining existing pipelines. The role We need a fullstack generalist who's genuinely comfortable moving across the stack, not because we don't value depth, but because at our stage the highest-leverage engineers are the ones who can pick up whatever's actually blocking the team that week, whether that's a backend service, a frontend component, or a deploy pipeline. You'll be one of the first hires into a team that's actively consolidating separate products into one unified platform, and you'll have real influence over how that gets built, not just execution on a finished spec. You'll work on: migrating and unifying our data model, building out cloud infrastructure, and shipping product features across our core tools, with a growing AI/vision pipeline underneath all of it. What you'll actually work on Backend services in Python and Node, we're consolidating onto this from a legacy Go stack, so comfort picking up a codebase mid-migration matters more than years of experience in either language specificallyFrontend work in React, migrating our product surfaces off a legacy Astro/Lit stack onto one unified frameworkA unified Postgres data modelBuilding and consuming REST APIs for partner/integration workContainerized services (Docker) as part of our CI/CD and deployment pipelineInfrastructure-as-code with Terraform (or similar) and CI/CD pipelines as we migrate to a newer cloud setupCollaborating directly with product and our AI/ML engineer as vision-model extraction and RAG-based features come online What We're looking for: 2+ years of professional experience building and shipping production software across both backend and frontendReal, hands-on experience with Python (Node is a plus) in production, since that's what our backend is consolidating ontoSolid React experience (with TypeScript), component architecture, state management, the fundamentals, not just having touched it onceReal experience with Postgres specifically, or another relational database with strong SQL fundamentals, you'll be working on a genuinely important shared schema, not just calling an ORMComfortable writing automated tests (unit/integration), some of what we build feeds directly into cost and compliance decisions, so correctness matters more here than in a typical productSome exposure to CI/CD pipelines, Docker, and infrastructure-as-code (Terraform or similar), you don't need to be a DevOps specialist, but you should be comfortable reading and modifying a pipeline, a Dockerfile, or a Terraform module, not seeing one for the first timeComfortable with cloud infrastructure basics, deploying services, reading logs, debugging a production issueFluent enough in German to work with domain content (cost data, building regulations, customer-facing text)Professional working proficiency in English (our internal tech conversations run in English) Not required, but a big plus: Direct experience migrating a legacy codebase (any stack) onto a new one, you understand the specific discipline of shipping features while a migration is happening underneath youExperience working at a small startup or on a small team, where you've had to own something end-to-end rather than a narrow sliceSome exposure to AI/ML-adjacent engineering, not deep ML expertise, but comfort calling model APIs, handling structured/unstructured data pipelines, or working alongside an ML engineerExperience with fintech, proptech, or another regulated/compliance-adjacent domain, you understand that "the number has to be exactly right" is sometimes a real constraint, not a nice-to-haveAwareness of data security/privacy basics, you'll be working with financial documents and personal property dataFamiliarity with German building/renovation concepts (DIN 276 cost classification, Energieausweis, GEG), not required, genuinely a bonus if you have it What We're NOT looking for: Someone who only wants to work in one narrow specialty, this role will move across the stack as the platform consolidatesA purely remote-first candidate, we're building "Architecture Days" and real in-person collaboration with non-technical teams into how we work, which requires at least 2 days per week in the office What We offer Competitive compensation: €60,000–80,000 based on experienceReal architectural ownership: Shape the technical foundation of a platform that's still being actively built — not one you're simply bolted ontoHigh-impact, low-bureaucracy environment: Join a small team where your work is immediately visible and matters, rather than getting lost in a large engineering orgFlexible hybrid setup: Work from our office at least 2 days a week, with flexibility for the rest How to apply Send us your CV and a short note on the most interesting technical problem you've solved recently, we care more about how you think through a real problem than a polished cover letter.