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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Lead Fullstack Engineer - **Company:** hallo theo - **Location:** Berlin, Germany - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Microsoft Azure, Software as a Service, Continuous Integration, Python (Programming Language), Software Engineering, SQL Databases, Data Streaming, Web Application Frameworks, Data Logging, Large Language Models, Backend, Data Layers, Front End Software Development, Code Restructuring, GXP, Programming Languages - **Published:** June 6, 2026 - **Apply:** https://de.indeed.com/viewjob?jk=03dd0e266d9d8dd9 ## About the Role Do you have experience in SaaS?, As Lead Fullstack Engineer at hallo theo, you design, build and operate the core systems of our AI-native property management platform. You work hands-on across the stack - from intuitive frontends to robust backend services and data flows - and take real ownership for critical user journeys. You work with great attention to detail, empathy and a solution-oriented mindset, with a strong feel for both our users and our technology, and you help turn ambiguous problems into simple, impactful product experiences., * 6-8 years of experience in software engineering, ideally in product-driven environments (startups, scale-ups or similar), with a strong track record in complex and uncertain projects. * Strong product mindset: you think in user journeys and outcomes, not just tickets, and you are comfortable making trade-offs under ambiguity. * Solid understanding of LLMs, RAG and current AI trends, and motivation to apply them pragmatically in a real product. * Proficient in at least one modern programming language and experienced in a web tech stack (e.g. Python and SQL, plus modern web frameworks and APIs). * Experience operating services in the cloud (e.g. AWS, GCP or Azure), including CI/CD, logging, monitoring and basic security practices. * Business-fluent German (C1 or higher) and strong English skills, as you'll work with German-speaking stakeholders and an international team. Nice to have * Experience in domains with complex operations or workflows (e.g. proptech, fintech, marketplaces or B2B SaaS). * Prior experience in a "tech lead" capacity (leading projects or streams), even without formal line management. ## Description * Own the end-to-end delivery of features and services - from discovery and technical design through implementation, testing, rollout and monitoring in production. * Build and evolve reliable backend and frontend components (APIs, services, UIs) that integrate with our web tech stack and data layer. * Improve our architecture and codebase: refactor, define clear interfaces and keep our platform secure, observable and maintainable. * Collaborate closely with Product, Design and Operations to shape scope, break down complex problems and make pragmatic trade-offs between speed and quality. * Act as a technical sparring partner and mentor for other engineers, supporting good engineering practices and a healthy engineering culture. ## Related Videos - [Why Your AI Agent Keeps Hallucinating Your Data: Building Deterministic Context Layers](https://www.wearedevelopers.com/videos/2055-why-your-ai-agent-keeps-hallucinating-your-data-building-deterministic-context-layers) - [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock) - [Blueprints for Success: Steering a Global Data & AI Architecture](https://www.wearedevelopers.com/videos/1577-blueprints-for-success-steering-a-global-data-ai-architecture) - [Beyond Hiring: Building a Sustainable Talent Acquisition Engine at Deutsche Bahn](https://www.wearedevelopers.com/videos/1856-beyond-hiring-building-a-sustainable-talent-acquisition-engine-at-deutsche-bahn) - [How to govern Vibe Coding for the Enterprise](https://www.wearedevelopers.com/videos/100290-how-to-govern-vibe-coding-for-the-enterprise) - [Nest.js - TypeScript in the backend can also be clean](https://www.wearedevelopers.com/videos/1033-nest-js-typescript-in-the-backend-can-also-be-clean) ## Related Articles - [The Biggest German Tech Companies](https://www.wearedevelopers.com/magazine/424-the-biggest-german-tech-companies) - [Finding Jobs in Germany](https://www.wearedevelopers.com/magazine/375-finding-jobs-in-germany) - [Where to Find German Tech Jobs](https://www.wearedevelopers.com/magazine/366-where-to-find-german-tech-jobs) - [How to Find Tech Jobs in Berlin](https://www.wearedevelopers.com/magazine/291-how-to-find-tech-jobs-in-berlin) - [Find a Developer Job: 12 Best Job Sites For Developers](https://www.wearedevelopers.com/magazine/165-find-a-developer-job-12-best-job-sites-for-developers) - [Where To Find Software Engineering Jobs](https://www.wearedevelopers.com/magazine/396-where-to-find-software-engineering-jobs)