Feature flags for backend services

Backend services often need feature flags for operational control more than visual rollout.

Typical backend flag uses:

• enable or disable a route
• switch between old and new implementations
• turn off an expensive integration
• guard risky background jobs

Backend flags are often the highest-leverage flags in a system because they control behavior that the rest of the stack depends on.

Why server-side flags matter

Server-side flag evaluation lets you:

• keep sensitive behavior off the client
• centralize operational decisions
• hide implementation details from frontend apps

In Nona, that is where server scope is especially useful.

Common backend flag patterns

Examples:

• Features:UseLegacySearch
• Features:DisablePayments
• Features:UseAsyncCheckoutWorker
• Features:EnableNewRouting

These names are useful because they describe the behavior the operator is controlling.

Recommended backend patterns

• use server scope for backend-only flags
• keep flag names clear and operationally meaningful
• validate the default behavior when the flag is off
• treat history and rollback as part of your incident path

How to create one

In admin:

1. open Projects
2. open the backend service project
3. select the target environment
4. click Add Parameter
5. create a boolean entry such as Features:DisablePayments
6. choose server scope
7. click Create

With the CLI:

nona entries set \
  --project payments-api \
  --environment production \
  --key Features:DisablePayments \
  --value false \
  --scope server \
  --content-type boolean

How a backend service reads it

In .NET:

using Nona.Client;

using var client = new NonaClient(
    "https://nona.example.com",
    "production",
    apiKey: Environment.GetEnvironmentVariable("NONA_API_KEY"));

var flag = await client.GetConfigValueAsync("Features:DisablePayments");
var paymentsDisabled =
    flag.ContentType == "boolean" &&
    string.Equals(flag.Value, "true", StringComparison.OrdinalIgnoreCase);

A service in another language can use HTTP against the same key.

How to operate it

When a backend path needs to be disabled:

1. open the parameter row
2. change the value
3. click Save
4. review the History tab if you need to roll back

For high-risk flags, keep the flag names explicit enough that an operator can safely understand them during an incident.

Why backend flags pair well with Nona

Nona gives backend teams a practical combination:

• plain HTTP access
• official .NET client support
• feature flags and broader runtime config in one service
• rollback and audit visibility when something changes in production

That makes it a good fit for services that need both operational toggles and runtime settings.

Related docs

• Client vs server scope
• Kill switches
• .NET client
• HTTP

FAQ

Why are backend feature flags important?

They control behavior that the rest of the stack depends on, such as route gates, integrations, and operational toggles.

Should backend flags use server scope?

Usually yes.

Backend-only flags should stay on server scope whenever possible.

Can backend flags work as kill switches?

Yes.

Backend flags are often some of the highest-value kill switches in a system.

What is a good first backend flag?

A clear operational flag such as Features:DisablePayments or Features:UseLegacySearch is usually a strong first candidate.