AI builds, senior engineers review
Nexera AI uses AI on every step of a build and puts a senior developer on every gate. Each feature starts as written Product Requirements, becomes a spec, ships with automated tests and passes only when it meets agreed acceptance criteria. That is how an MVP goes live in 2–4 weeks and keeps working after launch.
Requirements, specs, tests, acceptance criteria
Every feature goes through the same four steps. The written record keeps the AI on track and gives you something to check.
Product Requirements
We write down what the product must do in plain language you can review, so the AI has nothing vague to invent around.
Specs
Each requirement becomes a precise technical spec that the AI implements against. Every change can be traced back to one.
Tests
Automated tests are written alongside the code and run on every commit, so behaviour is checked by a machine every time.
Acceptance criteria
A feature is done when it meets criteria agreed with you in advance. A senior developer is the final gate.
Plan, Act, Verify, Review, with a developer in the loop
AI agents work in a tight loop. A developer steers each turn and decides when the work is good enough to merge.
Plan
The agent reads the spec and the codebase and proposes a plan for the change. A developer adjusts it before any code is written.
Act
The agent writes the code and the tests for that change, inside the project's own conventions and tools.
Verify
Lint, type checks and tests run automatically. Anything that fails goes back to the agent with the error.
Review
A senior developer reads the diff, checks it against the spec, and approves it or sends it back. What we learn at release feeds the next Plan.
AI on every step, a human on every gate
We use AI from planning to deployment. A developer signs off at each handoff before the next step starts.
| What AI does | Gate | What the developer does | |
|---|---|---|---|
| Plan | Drafts requirements, risks and estimates from your brief. | Scope signed off | A developer picks the slice worth building first. |
| Write | Generates and refactors code against the approved spec. | Spec matched | Each change is checked against the spec it implements. |
| Review | Summarises every diff and flags risky changes. | Merge approved | A developer reads the diff before anything merges. |
| Test | Writes unit, integration and E2E tests and runs them in CI. | Criteria met | Acceptance criteria are verified, not assumed. |
| Ship | Deploys through CI/CD and monitors real usage. | Release approved | A developer signs off the release to production. |
Six checks every change passes before it merges
These run on every commit, on every project. A change that fails any of them does not reach the main branch.
- Lint: code style and common mistakes are flagged automatically.
- Type check: the compiler checks that data flows through the code as the spec says.
- Unit tests: small automated tests check each piece of logic on its own.
- E2E tests: end-to-end tests click through the core journey, such as sign-up, the main action and payments.
- Security scan: dependency audits, secret scanning and OWASP checks look for known security problems.
- Human review: a senior developer reads the diff and approves it, or sends it back.
Vibe coding compared with our method
| Typical vibe coding | Nexera AI | |
|---|---|---|
| Starting point | A prompt | Written Product Requirements and a spec |
| Who checks the code | Often nobody, until something breaks | A senior developer reads every diff |
| Tests | Rarely written | Written with every feature, run on every commit |
| Security | Keys and data access are often left open | Secret scanning, dependency audits and an access review |
| When it's done | When it looks right | When it meets the agreed acceptance criteria |
| The next change | Can quietly break what worked | Tests catch regressions before they merge |
Vibe coding here means prompting AI tools to generate an app without specs, tests or review. The same tools can be used well; the process around them makes the difference. Stuck with a vibe-coded app? See AI App Rescue.
Which AI tools see your code?
Only AI services on enterprise or API plans with training opt-out, so your code and data are never used to train models. Client code never goes into consumer chat apps. On request we use your own accounts and keys, or self-hosted open-source models.
Training opt-out
We only use AI services on enterprise or API plans that exclude training, so your code and data are never used to train models.
No consumer chat apps
Client code never goes into consumer chat apps.
Your accounts on request
We can work with your own AI accounts and API keys, or with self-hosted open-source models.
NDA before kickoff
We sign your NDA, or ours, before any project details change hands.
Who owns what
- Code lives in your repository from the first commit, so you can see progress every day.
- Once a Milestone is paid, its source code, infrastructure and documentation are yours. No lock-in and no licence fees.
- A Clickable Prototype stays with Nexera AI until you sign a follow-on agreement. Without one you keep screenshots and a PDF walkthrough. See the Prototype & Code Audit Terms.
- We use mainstream technology and write handover docs as we go, so any developer can pick the code up later.
Questions, answered
Is AI-generated code safe to use in production?
Yes, when it is specified, tested and reviewed. Every change we ship passes six gates, including automated tests, a security scan and a review by a senior developer.
What is the difference between vibe coding and software engineering with AI?
Vibe coding prompts an AI until the app looks right. Engineering with AI starts from written requirements and specs, adds automated tests and has a developer approve every change against agreed acceptance criteria.
How does an AI development agency work?
AI writes most of the code, tests and documentation, and senior developers plan the work and review every change. At Nexera AI that is one or two senior developers per build, which is how an MVP goes live in 2–4 weeks.
Does a human review the code the AI writes?
Yes. A senior developer reads and approves every change before it reaches the main branch, and signs off each release to production.
What happens if the AI gets something wrong?
Tests and review catch it before it merges. A change that fails a test, a check or the developer's review goes back to be fixed, and nothing is accepted until it meets its acceptance criteria.
Will my code be used to train AI models?
No. We only use AI services on enterprise or API plans with training opt-out, and on request we work with your own accounts, keys or self-hosted models.
Which AI tools do you use?
Mainly Claude Code and Codex for development, with models from Anthropic and OpenAI, or open-source models when a project needs them. The product itself is built on mainstream technology such as React, Next.js, React Native, Node.js and PostgreSQL.
Can you work inside our existing codebase and process?
Yes. We follow your stack, tools and review process, and the same gates apply to every change we make in your repository.
See the method on your own idea
Book a free 30-minute Scope Call. A senior developer writes the first Product Requirements with you, and you get a Ballpark for the build.
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