In an increasingly fragmented microservices ecosystem, choosing an API gateway is no longer a matter of simple traffic management, but of the company’s resilience strategy. For architects and technical decision-makers, the question is no longer “which gateway should I choose?”, but “which data architecture and which API lifecycle match my infrastructure?”.
Numendo breaks down the four market-leading solutions for you — Kong, Gravitee, Tyk and HAProxy — from the angle of raw performance, extensibility and governance.
Understanding the role of an API gateway in a modern architecture
At the heart of microservices ecosystems, the API gateway acts as a conductor, or single point of entry. More than a simple proxy, it positions itself as a strategic interface between data consumers (clients, mobile apps, partners) and the complexity of the back-end infrastructure. Its role is to intercept incoming requests in order to validate them, transform them and route them intelligently to the appropriate services.
A shield and an enabler of interoperability
One of the gateway’s major advantages lies in decoupling systems. It allows heterogeneous platforms to communicate smoothly without ever directly exposing internal services. In an enterprise setting, this means that different business entities can exchange critical data via secure endpoints, thereby preserving the integrity of source systems and avoiding excessively tight technical coupling.
Added value for DevOps teams
Far from being a simple routing layer, the API gateway centralises essential cross-cutting functions, freeing developers from redundant and complex tasks:
- Security and identity: centralised management of authentication (OAuth2, JWT, OIDC).
- Traffic control: implementation of rate limiting and quota policies to protect the back end against overload.
- Performance optimisation: caching strategies to reduce latency.
- Protocol mediation: dynamic transformation of requests (e.g. converting XML to JSON) to ensure compatibility between legacy and new systems.
By delegating these responsibilities to the gateway, the company not only improves the robustness of its information system, but also accelerates its deployment cycles by simplifying the business logic of its applications.
1. Kong Gateway: the “cloud-native” standard
Built on Nginx and the OpenResty framework, Kong remains the undisputed leader thanks to its light footprint and its plugin ecosystem.
- Architecture: written in Lua, Kong strictly separates the control plane (Konnect or hybrid deployment) from the data plane.
- Strengths: a minimal memory footprint (less than 300 MB of RAM by default) and near-linear horizontal scaling capability.
- New in 2026: native integration of the AI Gateway, making it possible to standardise API signatures for LLMs (OpenAI, Anthropic) with centralised governance of tokens and inference cost.
- Ideal for: complex Kubernetes architectures and service mesh deployments via Kong Mesh (Kuma).
2. Gravitee.io: the power of event-native
If your APIs are not limited to REST but also include data streaming, Gravitee is the most mature player.
- Architecture: a Java/JVM solution, demanding in terms of resources but extremely robust for complex transactions.
- Strengths: it is one of the few tools to offer unified management of synchronous (REST, gRPC) and asynchronous (Kafka, MQTT, webhook) protocols. Its management interface (Cockpit) is the most intuitive for development teams.
- Differentiator: a highly granular policy engine that allows code to be injected without restarting the nodes.
- Ideal for: companies in the banking or industrial sector requiring advanced protocol mediation.
3. Tyk: the Go and GraphQL alternative
Tyk stands out with a modern architecture written in Go, offering an ideal compromise between performance and ease of maintenance.
- Architecture: unlike Kong, which relies on Nginx, Tyk has its own network stack in Go.
- Strengths: native, high-performance handling of GraphQL (Universal Data Graph). Tyk makes it possible to merge several data sources into a single GraphQL endpoint without excessive latency.
- Data management: a strong dependency on Redis for rate limiting and session management, which guarantees high execution speed for high-traffic APIs.
- Ideal for: “full-Go” oriented teams and GraphQL-centric projects.
4. HAProxy: raw performance at layer 4/7
Often seen as a simple load balancer, HAProxy has established itself as a formidable gateway for those who prioritise ultra-low latency.
- Architecture: written in C, single-process and event-driven.
- Strengths: processing capacity exceeding 2 million requests per second on a single node. Its configuration is static (or via the Runtime API), which makes it the most stable solution on the market.
- Limitations: fewer out-of-the-box features for the API lifecycle (developer portal, monetisation) compared with a Gravitee or a Tyk.
- Ideal for: edge computing, large-scale DDoS protection and high-performance environments where every microsecond counts.
Pricing models and TCO: the real cost of your architecture
Beyond technical features, the budget impact of an API gateway depends on its billing philosophy. In 2026, the market splits into three models: consumption-based (requests/services), flat-rate (fixed licence), or per node (infrastructure).
Cost comparison table
Here is a breakdown of the real total cost of ownership (TCO) for each solution:
| API Gateway | Open source version | Paid / SaaS model | Main billing metric | Cost profile & TCO |
|---|---|---|---|---|
| Kong | Yes (Kong Community) | Kong Konnect (SaaS) or Enterprise (self-hosted) | Number of connected services, request volume and premium plugins (e.g. AI Gateway). | High at scale. Very accessible to get started, but the hybrid pricing (services + volume) and access to enterprise plugins quickly push Enterprise contracts up (often beyond €40,000/year). |
| Gravitee.io | Yes (Community Edition) | Gravitee Managed (SaaS) or Enterprise (plugins) | Feature tier (security/alerting packs), support and hosting options. | Predictable and structured. The turnkey managed solution starts at around €2,500/month. It removes DevOps operational debt by including infrastructure and maintenance in a fixed cost. |
| Tyk | Yes (Tyk OSS) | Tyk Cloud (Starter to Grow) or Pro/Enterprise plans | Mixed: usage-based tiers for Cloud, or a fixed plan (Pro plan) with unlimited requests. | The most flexible. Tyk stands out with its “no request limits” policy on its higher tiers, avoiding financial penalties for companies whose traffic takes off. |
| HAProxy | Yes (HAProxy Community) | HAProxy Enterprise / Fusion | Fixed annual licence per instance (node), regardless of traffic volume. | The lowest TCO for massive traffic. An extremely predictable model. Whether you handle 10,000 or 2 million requests per second, the licence cost stays the same. |
Economic subtleties to keep in mind
- Kong and plugin dependency: while Kong’s open-source version is powerful, many features that are essential in an enterprise (such as advanced OIDC/SSO integration or token-based rate limiting for AI) require the Enterprise version. Work out your trajectory carefully before committing.
- Gravitee and the ROI of event management: Gravitee’s cost is fully justified if you make use of its event-native architecture (Kafka, MQTT). Choosing Gravitee purely for basic REST proxying can prove financially oversized.
- Tyk and budget predictability: for cloud-centric projects or complex GraphQL architectures, Tyk’s fixed plans offer excellent peace of mind for CFOs, because infrastructure costs do not rise linearly with the application’s success.
- HAProxy and the hidden cost of engineering: while HAProxy offers the most unbeatable licence cost for very high throughput, it requires sharper systems engineering skills to be configured as a genuinely complete application gateway (no native developer portal, more static configuration).
Numendo expertise: our architects’ view
The choice of an API gateway directly affects your time to market. In 2026, the trend is towards the “specialist gateway” rather than the universal tool:
- Looking for extreme scalability: favour Kong or HAProxy.
- Need for governance and compliance (GDPR/banking): Gravitee is the most structuring solution.
- Data/GraphQL modernisation: Tyk offers the cleanest implementation.
Expert’s note:
Beware of the technical debt linked to plugins. Too many custom plugins on a gateway like Kong can make version upgrades critical. At Numendo, we recommend a “Gateway-as-Code” approach to automate your deployments via Terraform or Helm.
Conclusion: optimising your API management strategy
The API gateway is the nerve centre of your security and your digital performance. Whether you are in a cloud migration phase or redesigning microservices, working with an expert partner such as Numendo makes it possible to validate your POCs against real load criteria.
Would you like to audit your current API architecture? Contact the Numendo experts for a tailored performance and security analysis.
