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Sebastian Consulting

Architecture and engineering for complex web applications.

We help engineering teams modernize React and TypeScript applications, bring products into more languages, and build a delivery process the team can maintain.

Architecture reviews, hands-on development, and knowledge that stays.

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Two architects. Direct responsibility.

Experience.
Clarity.
Enthusiasm.

You work directly with the two architects doing the work: no bench, no juniors, no handover to third parties.

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  • Sebastian Werner

    Sebastian Werner

    Co-founder

  • Sebastian Fastner

    Sebastian Fastner

    Co-founder

More speed needs better judgment.

AI accelerates implementation. What matters is what gets built, how it fits the architecture, and what quality looks like. That is where we take responsibility.

Services

  • Make the next change easier.

    When a web application has become hard to change, we review the architecture with your team, make tradeoffs visible, and help implement the next step in React and TypeScript. You get a target picture, a reasoned decision, and a migration path the team can carry.

  • Bring the product into more languages.

    We help turn internationalization into a maintainable product capability, from code and catalogs to context, translation workflows, and delivery, so new languages stop being a project of their own.

  • Leave the team stronger.

    Pairing, reviews, and practical standards help teams build shared judgment, including clear guardrails for AI-assisted delivery. Knowledge, tools, and standards stay when we leave.

What needs to become clearer?

Tell us where architecture, delivery, or internationalization is getting in the way.

15 minutes, no strings attached: you talk directly to one of the two Sebastians.

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Newsletter

Insights into our work across software and consulting: what we're building, exploring and thinking about.

See what we build beyond consulting.

We build products, open-source projects and agent tools for everyday work.

Discover Sebastian/Software

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