Owns the server side end to end
Your backend engineer owns everything behind the interface: APIs, data models, background jobs, integrations and the infrastructure glue between them. They write the code, run the operations, and stay answerable for how it behaves under load.
What to verify: Ask which services, queues and data stores the engineer will personally own, and who is paged when they misbehave.
APIs with clear contracts
Endpoints with versioned contracts, permissions enforced on the server, and changes that stay backward compatible or are migrated deliberately. Consumers of the API, including AI agents, get documentation they can rely on.
What to verify: Ask how API changes are versioned, where contracts are documented, and how breaking changes are rolled out.
Data models that survive change
Schema design for the queries the product actually makes, migrations that run safely on live data, and indexes justified by measurements. The data layer is designed to be changed, not to be feared.
What to verify: Ask how migrations are applied to production, how rollbacks work, and what proves a query performs at scale.
Jobs and integrations that do not drop work
Queues with retries, idempotent handlers, backpressure when a dependency slows down, and third-party integrations that degrade gracefully. Work that enters the system is tracked until it is done.
What to verify: Ask what happens when a job fails twice, when a provider is down, and how lost work is detected.
Reliability you can measure
Metrics, structured logs and traces around the paths that matter, alerts that fire on symptoms users feel, and load tests before the traffic arrives. Uptime is a number the team watches, not a hope.
What to verify: Ask what is monitored, what alerts page a human, and what the last load test showed.
Handover that leaves your team stronger
Every service, schema and decision lives in your repository with written rationale and runbooks. When the engagement ends, your team operates and extends the system without us in the loop.
What to verify: Ask where runbooks and architecture decisions live, and who on your side can add a feature after handover.