Sankalpsutra Tech
API GATEWAY PATTERN

Unify client access without exposing service sprawl

We help teams design API gateways for routing, authentication, rate limits, request aggregation, protocol translation, and versioning across backend services.

Gateway request map

Single entry with controlled backend access

1Client Request
2Auth / Rate Limit
3Route / Transform
4Aggregate
5Backend Services
6Logs / Traces
RoutingAuthRate limitsAggregationVersioningObservability

WHY API GATEWAY

Clients should not own your internal service topology

Direct service exposure creates brittle clients, duplicated auth logic, and uncontrolled traffic patterns.

Problem panel

  • Mobile and web clients call many backend URLs
  • Auth and rate limits duplicated per service
  • Breaking internal changes leak to clients
  • Composite screens require chatty client orchestration
  • No central visibility into API traffic

Gateway sprawl is as risky as no gateway. We keep policy centralized and logic thin.

Gateway-controlled access path

Clients see one surface. Policies and routing stay server-side.

  1. 1

    Single public endpoint

    Stable client integration

  2. 2

    Apply auth and limits

    Central policy enforcement

  3. 3

    Route to services

    Hide internal topology

  4. 4

    Transform payloads

    Version and shape responses

  5. 5

    Aggregate when needed

    Fewer client round trips

  6. 6

    Log and trace requests

    API-level observability

PATTERN MAP

Core patterns behind scalable API gateways

Each control reduces client coupling or operational blind spots.

  • Path-based routing

    What it solves

    Direct requests to the right backend service

    Where it fits

    Microservices and modular backends

    Risk avoided

    Clients hard-coded to internal hosts

  • Centralized authentication

    What it solves

    JWT validation and scope checks at the edge

    Where it fits

    Multi-service SaaS APIs

    Risk avoided

    Inconsistent auth across services

  • Rate limiting

    What it solves

    Protect backends from abuse and bursts

    Where it fits

    Public APIs and partner integrations

    Risk avoided

    Uncontrolled traffic overwhelming services

  • Backend for frontend

    What it solves

    Client-specific aggregation and shaping

    Where it fits

    Mobile vs admin vs partner apps

    Risk avoided

    One generic API for every client type

  • API versioning

    What it solves

    Backward-compatible client migration

    Where it fits

    Long-lived mobile and partner clients

    Risk avoided

    Breaking changes without a migration path

  • Request transformation

    What it solves

    Protocol and payload adaptation at the edge

    Where it fits

    REST to gRPC or legacy adapter paths

    Risk avoided

    Transformation logic scattered in services

  • Circuit breaking

    What it solves

    Stop routing to unhealthy backends

    Where it fits

    High-traffic composite endpoints

    Risk avoided

    Gateway amplifying downstream failures

  • Distributed tracing

    What it solves

    Trace requests from gateway through services

    Where it fits

    Incident response and latency tuning

    Risk avoided

    Missing correlation across hops

TECHNOLOGY DECISIONS

Choosing the right gateway platform

Platform choice depends on cloud alignment, policy needs, and team operations capacity.

Kong

Best fit
Self-hosted or hybrid API management
Delivery model
Plugin-based gateway
Operational complexity
Moderate to higher
Retry / DLQ support
Via upstream retry plugins
Scale pattern
Horizontal gateway nodes
When we recommend it
Multi-cloud or self-hosted API platforms

Azure API Management

Best fit
Azure-native API products
Delivery model
Managed gateway and policies
Operational complexity
Lower (managed)
Retry / DLQ support
Policy-based retry and cache
Scale pattern
Units and regional gateways
When we recommend it
Azure estates and enterprise API governance

AWS API Gateway

Best fit
Serverless and AWS-native APIs
Delivery model
Managed REST/HTTP APIs
Operational complexity
Lower
Retry / DLQ support
Integration with Lambda and SQS
Scale pattern
Managed scaling
When we recommend it
AWS-first serverless and Lambda backends

Ocelot

Best fit
.NET microservice gateways
Delivery model
In-process ASP.NET gateway
Operational complexity
Moderate
Retry / DLQ support
Polly policies in gateway
Scale pattern
Scale gateway app like any service
When we recommend it
.NET platforms needing a lightweight gateway

Envoy / mesh edge

Best fit
Service mesh ingress and L7 routing
Delivery model
Proxy with advanced traffic control
Operational complexity
Higher
Retry / DLQ support
Mesh retry and outlier detection
Scale pattern
Sidecar and ingress scaling
When we recommend it
Kubernetes platforms with mesh maturity

IMPLEMENTATION OWNERSHIP

Implementation layers we own for API gateway platforms

Thin gateway, explicit policies, and phased route migration.

Gateway delivery map

  1. Inventory
  2. Policy
  3. Route
  4. Secure
  5. Migrate
  6. Observe

  • API surface inventory

    Catalog client endpoints, consumers, and breaking-change risk.

    • API catalog
    • Consumers
    • Deprecation plan

  • Auth and policy design

    Scopes, tokens, rate limits, and tenant-aware rules.

    • JWT/OAuth
    • Scopes
    • Rate limits

  • Routing and transformation

    Path maps, payload transforms, and protocol adapters.

    • Routes
    • Transforms
    • Adapters

  • BFF aggregation

    Composite endpoints for mobile and admin experiences.

    • Aggregation
    • Response shaping
    • Caching

  • Versioning strategy

    Version headers, parallel routes, and sunset policy.

    • v1/v2 routes
    • Sunset dates
    • Client migration

  • Gateway observability

    Access logs, metrics, tracing, and alert thresholds.

    • Access logs
    • Latency SLOs
    • Trace IDs

OUTCOMES

What API gateway architecture delivers

Clients integrate once. Policies and routing evolve behind a stable edge.

  • Stable client integration

    Backend topology changes without client rewrites.

    Outcome signal

    Fewer client-breaking releases

  • Central security controls

    Auth, scopes, and limits enforced consistently at the edge.

    Outcome signal

    Uniform API policy

  • Fewer client round trips

    Aggregation reduces chatty mobile and web flows.

    Outcome signal

    Lower client latency

  • API traffic visibility

    Logs and traces show who calls what and where failures start.

    Outcome signal

    Faster API incident triage

  • Controlled API evolution

    Versioning supports phased client migration.

    Outcome signal

    Safer API upgrades

Related architecture

Exposing many backend services directly to clients?

We can review your API surface, auth model, rate limits, aggregation needs, and versioning plan before gateway policy becomes a bottleneck.

View related case study