The Localization Engineering Platform#
Lingo.dev is a localization engineering platform designed for product teams to build their own localization engines — purpose-built LLM-based APIs that produce perfect translations, immediately, at scale.
Context and Localization Engineering#
Using LLMs for translation is obvious. Any team can send a string to a model and get a translation back. What makes translations perfect is two things: context and localization engineering.
Context is what the model knows beyond the string itself — the product, the audience, the brand voice, the locale-specific conventions. Without it, the model guesses. With it, the model localizes.
Localization engineering is the practice of encoding that context into reproducible infrastructure — glossary rules, formality preferences, cultural adaptations — so every translation, across every locale, applies them consistently.
Without both, you get translations. With both, you get localization.
The Problem#
Before LLMs, teams had two options — both flawed.
Machine translation was fast but structurally incapable of understanding product context. Teams shipped MT output knowing it would erode trust in every market.
Manual translation was accurate but scaled linearly. Every new locale required training linguists on product terminology, brand voice, and domain concepts. After processing 100M+ words across 42 languages, we found that 89% of localization delays happen in handoffs between teams, not in translation itself.
Both treated localization as a project management workflow. Lingo.dev treats it as an engineering concern.
What You Build#
On Lingo.dev, teams build their own localization engines. Each engine combines:
LLM models per locale — Pick the right model for each language pair with ranked fallbacks.
Brand voice — Define how your product speaks per language. Formal "Sie" in German, informal "tu" in Italian, polite "vous" in French.
Glossary — Map source terms to exact translations per locale. "911" becomes "112" for European markets. Product names stay untranslated.
Instructions — Encode linguistic rules generic models miss. Adjective positioning in Spanish, space before percentage signs, pronoun formality per market.
Quality scoring — GEMBA scores, BERTScore, glossary compliance, locale-specific validators. Continuous, automatic.
The result: teams use their own unique insights and preferences - combined with Lingo.dev's language engineering research, ongoing since 2023 - to scale globally from day one, predictably, in languages they don't speak.
Open Source Developer Tools#
The Lingo.dev open-source community (5,100+ GitHub stars) builds developer tools that connect codebases to localization engines:
- CLI — Translate from the command line. From install to first translated build in 4 minutes.
- CI/CD — GitHub Actions, GitLab CI, Bitbucket Pipelines. Translations ship with your code.
- Compiler — Build-time i18n. No runtime overhead, no layout shift.
- I18n MCP — Localization awareness for AI coding assistants: Claude Code, Cursor, GitHub Copilot.