<Tobias Leinss />

Hi 👋🏻, I'm Tobias Leinss.
I build privacy-first apps you can install today.

I design and ship small, focused apps that run on your own device. Most of them work fully offline; the AI features are optional and use a key you bring yourself. No accounts, no telemetry, no backend collecting your data.

📱 Apps I've built

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👋 A little about me

Tobias Leinss

I build custom-tailored software and the infrastructure behind it, end to end: AI integration and automation, mobile and desktop apps, web platforms, and the self-hosted infrastructure that runs them. I care about software that respects the people using it: local-first, transparent about what leaves the device, and pleasant to use.

Before focusing on my own apps I spent years building Web3 and AI systems for companies and teams: smart contracts, backends, devops and AI integration. That background still shows up in the apps.

🤖 AI consulting

The apps above are proof I can take an idea and ship it end to end. If your company needs that same delivery for custom-tailored (maßgeschneidert) work: AI and automation, plus the self-hosted infrastructure behind it, I take that on through Leinss Consulting: LLM assistants and chatbots, process automation, and the backends and devops to run them privately. If that's a fit, let's talk.

Recent projects

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Work Experience

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  • Oct 2025 - Present
    Gnosis
    Senior Backend Engineer

    Backend services and the full infrastructure behind the Circles protocol.

    gnosis.io

    services

    Four backend services written from the first commit, in TypeScript on PostgreSQL: authentication for the whole ecosystem, covering Sign-In with Ethereum and smart-wallet signatures; a referral service; a profile service that indexes onchain profiles and pins their content to IPFS; and a scoring service that keeps a sparse Merkle tree per group and serves the proofs the SDK presents at mint time, with only the root published onchain.

    indexing

    The largest share of the work on the protocol’s Nethermind plugin, which indexes Circles events inside the execution client and serves them as a queryable API. C# and .NET, alongside a marketplace API and event-driven trust-management workers.

    infrastructure

    Multi-host platform driven by Ansible: blockchain nodes, PostgreSQL with automated failover and streaming replication, connection pooling, reverse proxy and TLS, firewalling, and rolling deploys across staging and production.

    observability

    Hub-satellite monitoring stack of Prometheus, Loki, Grafana, Tempo and Alertmanager, with remote-write from the satellites, central log shipping, and alerting on node, database and endpoint health.

  • Feb 2025 - Present
    leinss-consulting.de
    Founder & Independent Consultant

    Consultancy delivering web products and process automation, run end to end from the productized offering through to delivery.

    leinss-consulting.de

    product delivery

    A production e-commerce storefront, a back-office product management application, and an events site, on PostgreSQL with row-level security, object storage and continuous deployment.

    integration

    Integration with a separately owned supply-chain system, so data moves between the two without manual re-entry.

Education

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  • May 2022 - May 2022
    Udacity
    Blockchain Developer nanodegree
  • Oct 2021 - Nov 2021
    Scrum Alliance
    Scrum Master
  • Jan 2019 - May 2022
    Freecodecamp Certificates
    Frontend Development Libraries, Data Visualization, Responsive Web Design, Backend Development and APIs, JavaScript Algorithms and Data Structures

🤝 Let's connect

Questions about an app, an invite to a beta, or a consulting project? Reach out by email or find me on the networks below.