Do I need a centralized control plane for API traffic if teams manage services independently?

Not always — but you usually need some shared control point, even if teams own services independently.

Short answer

If teams are truly independent, you do not need one big centralized control plane for all API traffic.
However, at scale, you almost always need central governance, shared standards, and a common enforcement layer for things like:

• authentication and authorization
• rate limiting and quotas
• API versioning and deprecation
• observability and auditing
• policy enforcement
• traffic routing, retries, and failover

Common patterns

1) Fully centralized control plane

A central platform team manages API policies and routing for everyone.

Pros

• consistent security and governance
• easier compliance
• simpler operations early on

Cons

• can become a bottleneck
• teams move slower
• weaker service autonomy

2) Fully decentralized

Each team owns everything for its services, including API management.

Pros

• high autonomy
• faster local decision-making
• better team ownership

Cons

• inconsistent policies
• duplicated effort
• harder incident response and compliance
• traffic behavior varies widely across services

3) Federated model, often the best fit

Teams own their services, but a central platform provides:

• guardrails and templates
• shared tooling
• policy-as-code
• common ingress/API gateway/service mesh standards

This gives autonomy without chaos.

When you likely need centralized control

You probably want a centralized or federated control plane if:

• you have many teams/services
• APIs are externally exposed
• you need strong security/compliance
• you want consistent SLAs and observability
• cross-service traffic behavior must be standardized

When you may not need it

You can skip a centralized control plane if:

• the system is small
• services are mostly internal
• teams are few and tightly coordinated
• traffic policies are simple
• compliance and audit requirements are minimal

Practical recommendation

For most organizations:
centralize policy and visibility, decentralize service ownership.

In other words:

• teams manage their services independently
• a platform team defines the rules and provides shared infrastructure

If you want, I can sketch a reference architecture for a federated API control plane.