How do you manage one frontend codebase shared by multiple teams?

[giorgiPapava]

Looking for advice from teams who've been here. We have a React + TypeScript + Refine + Vite admin panel hosting 5 separate apps ("gateways") in a single repo / single Vite build. Each gateway has its own backend API, its own team, and is fairly self-contained:

• Isolated routes, data provider, access control, permissions, and i18n namespace per gateway
• A central registry wires them together (data providers, access control, routes, app-switcher, types)
• A productionReady flag hides beta gateways from prod
• Shared infra: auth (OIDC), UI primitives (shadcn), a shared DataTable, env validation

It works, but with 5 teams in one repo we keep hitting friction:

1. Releases / branching — All teams commit to a shared test branch, so commits get mixed across gateways. To ship one gateway we cut a release branch and cherry-pick that gateway's commits out of the mix. Fragile and manual. How do you ship independently on a shared trunk?

2. Independent deploys — Single build means one team's change rebuilds/redeploys everyone. We've prototyped Module Federation / micro-frontends, but it's a big jump in complexity. Worth it for 5 teams, or overkill?

3. Ownership boundaries — No CODEOWNERS yet, any team can touch any gateway. CODEOWNERS, separate packages, enforced monorepo boundaries — what worked?

4. Shared code coupling — Our registry has circular-dependency landmines, and we're mid-migration to a shared npm package. Monorepo (pnpm/Nx/Turborepo) vs. published package vs. just discipline — what scaled?

Core question: for ~5 teams each owning a domain app in one frontend, would you stay monolith + good module boundaries, go monorepo with separate packages, or full micro-frontend? What did you regret?

Thanks 🙏