Senior Freelance Engineer (Mobile + Backend)

<p>We’re looking for a Senior Freelance Engineer (Mobile + Backend) to partner directly with the founder in building a scalable, data-driven system in the Digital Health / Femtech space.</p>
<p>This is a long-term, strategic collaboration with real influence on architecture, product direction, and system design with the potential for equity participation.</p>
<h2>Tasks</h2>
<ul>
<li>Analyze and evolve existing systems into a clean, scalable architecture</li>
<li>Own system design across mobile and backend, including data models and core logic</li>
<li>Ensure robust integration between mobile and backend systems</li>
<li>Lay the technical foundation for future features, algorithms, and product growth, and the evolution of business logic</li>
<li>Communicate decisions clearly and transfer knowledge to founder to enable long-term system ownership</li>
</ul>
<h2>Requirements</h2>
<ul>
<li>Seniority: 5–8+ years of experience in real product environments with strong engineering standards (testing, code quality, production readiness)</li>
<li>Strong experience with <strong>React Native, TypeScript</strong>, and mobile architecture</li>
<li>Advanced backend expertise (<strong>AWS</strong>)</li>
<li>Proven experience designing scalable architectures and refactoring complex systems, including modeling complex, state-driven systems and data logic</li>
<li>Experience with data modeling, system design, and data-driven or algorithmic products</li>
<li>Solid understanding of <strong>GDPR</strong> and handling sensitive data</li>
<li>Interest in (female) health and hormonal systems</li>
<li>Experience in digital health startups</li>
</ul>
<h2>Benefits</h2>
<ul>
<li>Flexible, remote-first work</li>
<li>Personal coaching support</li>
<li>Meaningful work: direct impact on women’s health through product and system design</li>
<li>Fair, structured compensation and a long-term perspective for strong collaboration</li>
</ul>
<p><strong>How You’ll Work:</strong> Freelance setup (individual or max. 2 people) 10–20 hours/week, working directly with the founder with a collaborative style that includes independent ownership, pair programming, code reviews, and architecture discussions.</p>
<p><strong>Please send:</strong></p>
<ul>
<li>Relevant projects (especially refactoring and system design/building)</li>
<li>A brief description of your approach to working with complex codebases</li>
<li>GitHub, code samples, or other insights into how you work</li>
</ul>
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