As lead of a new Vue 3 application with a mixed-experience team, how would you choose between the Options API and the Composition API?
answer
- what kind of app is it?
- build step or not
- guard rails versus flexibility
- TypeScript and reuse at scale
- conventions replace the guard rails
basics
~20 sFor a full application built with SFCs, choose the Composition API with <script setup>, as the Vue docs recommend, and offset its missing guard rails with written conventions, composable patterns and review; reserve the Options API for build-less or low-complexity work.
solid answer
~40 sI would start from the docs' own split: the Options API for no-build or low-complexity use such as progressive enhancement, and the Composition API with Single-File Components for full applications. A new app with a build step falls in the second group, especially if it uses TypeScript and will grow shared logic. The real risk with a mixed-experience team is that the Composition API removes the Options API's guard rails, so less experienced developers can write disorganised components. I would compensate rather than retreat: document how a component is laid out, provide a few reference composables with agreed input and return conventions, pair on reactivity pitfalls such as `.value` and cleanup, and enforce it in review. Mixing styles per developer preference is the option I would rule out.
go deeper
Recall the docs' split: the Options API for no-build or low-complexity use, the Composition API with SFCs for full applications.
Explain the trade-off concretely: guard rails and learning curve against organisation, reuse and TypeScript inference.
Recommend a default for a given app and list the conventions and reviews that make it work for the team you actually have.
Own the decision end to end: the criteria, the exceptions, the mitigation plan for team skill gaps, and the evidence that would reopen it.
## Frame the decision This is a judgment call with no single right answer, so the useful move is to make the inputs explicit. Four questions decide most cases: 1. **Is there a build step with Single-File Components?** Without one, `<script setup>` is unavailable. 2. **How complex will the application become?** Many features, shared logic across many components and long life favour the Composition API. 3. **Is the team writing TypeScript?** The Composition API infers types from plain variables; the Options API needs type machinery for `this`. 4. **What does the team already know?** Experience with reactivity matters more than experience with either syntax. ## What the Vue docs recommend For production use the docs give a direct split: use the Options API if you are not using build tools, or plan to use Vue mainly in low-complexity scenarios such as progressive enhancement; use the Composition API with Single-File Components for full applications. They also stress that both styles share the same underlying system and core concepts, so the choice is about organisation and reuse, not capability. ## The honest trade-off | Factor | Options API | Composition API | |---|---|---| | Learning curve | gentler; structure is given | needs a real grasp of reactivity | | Guard rails | built in | must be supplied by the team | | Scaling large components | concerns scatter across options | concerns stay together | | Logic reuse | mixins, no longer recommended | composables | | TypeScript | workable with `defineComponent()` | natural inference | | Build-less use | natural | only via an explicit `setup()` option | For a mixed-experience team the tension is clear: the Options API is kinder to juniors on day one, while the Composition API is kinder to everyone in year two. ## A recommendation for a new application For a new SPA with a build step, I would choose the **Composition API with `<script setup>`**, and invest in the missing guard rails: - **A component layout convention**: imports, props and emits, state, derived values, functions, watchers, lifecycle, in that order, with one concern per block. - **A composable convention**: `useX` naming, refs out, ref-or-getter inputs, cleanup on unmount, synchronous calls from setup. - **Reference implementations**: a handful of reviewed composables and components that new code copies. - **Onboarding on reactivity**: `.value`, refs versus reactive objects, what loses reactivity, and effect cleanup; these are where juniors trip regardless of style. - **Review checklist and linting**: the recommended lint rule set from the Vue ecosystem, plus the team's own checks for composable call sites. ## When I would choose differently - **No build step**, or Vue embedded in server-rendered pages for small interactive widgets: the Options API is simpler and the docs recommend it. - **A short-lived, low-complexity internal tool** built by developers who already know options well: the benefits of composition may never show up. - **A codebase that must share components with an existing Options API app**: consistency may outweigh the style's benefits for a time. ## What I would not do Letting each developer pick a style per component gives the worst of both: two mental models in code review, logic that cannot be shared cleanly, and no guard rails either way. Pick one default, document the exceptions, and revisit the decision only with evidence, such as onboarding time or defect patterns, rather than preference. ## How to present it State the default, the reasons tied to this app (build step, scale, TypeScript), the specific risks for this team, and the concrete measures that address them. Interviewers at this level are listening for the trade-off and the mitigation, not for loyalty to one style.
- Wouldn't the Options API be safer for the juniors on the team?Safer on day one, because the structure is given. But the core concepts are shared, and juniors still need reactivity fundamentals in either style. With conventions, reference composables and review, the Composition API's flexibility becomes an advantage as the app grows; retreating to options trades a short learning curve for long-term organisation and reuse costs.
- How would you know, six months in, whether the choice was right?Look at evidence rather than preference: onboarding time for new joiners, review comments about component structure, how much logic is reused through composables, defect patterns around reactivity, and TypeScript annotation burden. If the problems are organisational, tighten conventions before reconsidering the style.
saying these in an interview costs you the question
- The Composition API is always the right choice, even without a build step.
- The Options API is deprecated, so it is not a legitimate option for new code.
- Letting each developer choose a style per component is the most flexible policy.
- Choosing a style changes how Vue's reactivity behaves at runtime.
- Juniors do not need to understand reactivity if the team uses the Options API.