The Product Manager's Guide to Sending Webhooks

Webhooks enable applications to communicate automatically in real time by pushing data when specific events happen. They are event-driven, lightweight, and often used to automate various workflows without the need for manual intervention or constant polling for new data.

Key Benefits of Webhooks:

• Real-time Data Updates: Webhooks facilitate real-time data transfer between systems as soon as an event occurs.
• Resource Efficiency: Since webhooks push data instead of requiring constant polling, they reduce server load and operational costs.
• Seamless Automation: They automate tasks, enhancing workflows by triggering actions like notifications or system updates without human input.
• Simple Deployment: Since webhooks are standard HTTP requests, they are easy to implement across various applications, making them a versatile option for integrations.\

Example Use Cases:

• FinTech: Automatically notify accounting systems and users in real-time when a payment is processed or a transaction is approved.
• AI: Instantly alert customers or trigger workflows when a machine learning model completes training or processes a significant inference.
• Logistics: Send real-time updates to clients or internal systems when shipment statuses change, such as departure, arrival, or delay notifications.

Common Reasons For Adding Webhooks

1. Responding to Customer Demands

If your product contains critical and time-sensitive data (e.g. financial transactions or delivery updates), chances are that your team has received requests to subscribe to webhooks. You might see explicit requests for webhooks in sales or support channels. Or perhaps you'll see an implicit need via customers polling your API. Regardless, offering webhooks to push real-time events to your customers' systems not only helps them extract more value from your product and improve satisfaction, it will also improve your platform's extensibility and free up engineers from having to constantly build new integrations.

2. Reducing API Load

Constant polling of your APIs may be taxing your infrastructure and people resources, thus increasing operational costs. Webhooks provide a more efficient alternative, delivering data only when necessary and reducing the load on your API infrastructure. 

3. Securing New Deals & Keep Existing Ones Happy

There are new deals with webhooks showing up in the RFPs or you have marquee customers asking for webhooks to unlock new use cases. Incorporating webhooks can be a decisive factor in securing new deals and renewals, showcasing your commitment to providing a modern and efficient API ecosystem. 

4. Increasing Revenue & Reduce Churn 

Initiatives to increase revenue often benefit from the addition of webhooks, as the workflows and automations they power unlock significant value for your customers. This not only gives you the option to monetize webhooks, but also makes your product stickier and indispensable. When monetizing webhooks it's common for our customers to provide access to a single endpoint for free. From there, you may choose to charge a flat add-on fee for a higher limit of endpoints, gate full access of webhooks to only enterprise agreements, or tier access e.g. Tier 1 receives one endpoint, Tier 2 receives five endpoints, and Tier 3 receives ten endpoints (see Lob's pricing page). 

5. Improving Extensibility

Webhooks make it possible for your customers and partners to build on top of your platform. This flexibility can lead to innovative uses of your API, creating a more vibrant and engaged developer community. It also reduces the development burden on your team by easily enabling third-party integrations via low-code and no-code options.

Considerations For Building Webhooks In-house 

Delivering webhooks may seem simple at first, as they are just HTTP post requests; however, many companies face challenges managing the overall complexity around scalability, reliability, user experience, and security, all while keeping operational costs in check. Below are some of the main challenges and considerations one should address when building their own webhook system.

Reliability

A reliable webhook system must handle common HTTP call failures—such as server downtime, timeouts, and network issues—by implementing automatic retries. These retries should use an exponential backoff strategy over several days to maximize delivery success and minimize delay. Ensuring at least once delivery is critical, as even a single missed webhook can undermine customer trust and system reliability. For example, GitHub's lack of retry support leads to missed CI tasks, frustrating users and partners. Additionally, webhook systems must account for diverse server configurations and issues, such as incomplete TLS chains and HTTP quirks.

Security

Webhook implementations must adhere to standard HTTP security practices—such as using HTTPS, TLS 1.2+, and secure cipher configurations—but also face unique challenges that are often mishandled due to limited team experience. Svix helped create Standard Webhooks to help educate and fix some of the more common challenges, though security is hard, and you may have security issues even when following the spec.

Key challenges include:

• Authentication: Webhooks typically use request signing to verify authenticity, which differs from standard API calls. Standard Webhooks helps standardize this process.
• Server-Side Request Forgery (SSRF): Since webhooks allow user-defined URLs, attackers can exploit this to target internal systems, requiring strong safeguards from the sender.
• Service Flooding: Attackers may slow down or overwhelm systems by targeting endpoints with delayed responses, degrading performance and availability for others.

Scalability

Webhooks can be deceptively quiet—until they aren't. A single failure can cascade and bring down your entire service. This isn't theoretical: GitHub experienced major outages in 2023 due to webhook failures.

Webhooks can generate load orders of magnitude higher than your normal system traffic. Even scalable systems may not be ready for this. One API call can trigger multiple webhook events—just like Stripe, where a single payment might emit "charge successful," "invoice paid," "subscription paid," and "customer updated."

Since these events hit external systems, delays compound. 100 requests/second generating 4 events each becomes 400 events/second—and if each takes 5 seconds to process, the backlog grows rapidly.

Failures and retries further multiply the load. If a major customer goes down or an AWS region has issues, retries can spike traffic to 11,000–22,000 events per second. These exact numbers may not apply to you, but they should be directionally correct. They are also not theoretical, it's something we deal with at Svix all the time.

Quality of service (QoS)

In the previous section we talked about scalability, the second side of scalability is quality of service. It's one thing to make sure the system doesn't buckle under load, but it's another to make sure that it still performs within your latency SLAs (read: webhooks are sent quickly). A webhook sent with a 20s delay because the system is busy, may be as worthless as a webhook that's never sent at all. Consider a customer making a payment that takes 20s to register, or an AI workflow that's delayed by 20s. These make for a terrible experience.

While ensuring a certain quality of service for a certain customer under load is important, what's even more important is ensuring quality of service for customers that are not under load; or in other words avoiding noisy neighbors. While a customer may be willing to accept some processing delays when they generate an immense load, other customers that haven't generated the load won't be as tolerant. So it's important to make sure that load on one customer doesn't adversely affect others.

Observability

Webhooks are asynchronous—your customers don't control when they receive them, they just arrive when triggered. That's why observability is critical in production. Unlike API calls, where the caller knows if the request succeeded, webhooks are like a bank calling you—you won't know if you missed it or why, unless you have access to a detailed call log.

A webhook system must offer consumer-facing observability to diagnose issues, fix them, and redrive failed requests. Internally, you also need visibility into queues, workers, DLQs, and back-pressure, with proper monitoring and alerting across the stack.

Developer experience

One often-overlooked aspect of building webhooks is the developer experience. This is not just a nice-to-have, as a good developer experience is the difference between webhooks being adopted and webhooks not being adopted. So you should account for this extra work when building your webhook system.

One important aspect of webhooks developer experience is the aforementioned observability. Without this observability developers are flying blind, and are unable to effectively debug webhook delivery which is very important in both the initial implementation and on an ongoing basis.

A great experience also means offering a self-serve UI where customers can register webhooks, trigger test events, rotate secrets, and more—without relying on forms or support tickets. You should meet developers where they are, with support for multiple endpoints, varying auth standards (like OAuth 2.0 or tokens), and custom throttling limits to protect your customers during traffic spikes and avoid bringing their systems down.

Read "Why webhooks are harder than they seem" to learn more.

Build vs. Buy

In our experience working with companies, ranging from small startups to the Fortune 500, building a reliable webhook system in-house can take 6–12+ months (see case studies), tying up valuable engineering resources and reducing product velocity. Even after launch, teams must maintain and scale the system—handling retries, uptime, performance, and security—which becomes an ongoing, long-term burden. While it may seem cost-effective initially, the ongoing infrastructure and support costs often outweigh the benefits. By choosing a solution like Svix, teams get a battle-tested, scalable platform with built-in retries, high availability, and enterprise-grade security, all deployable in days, not months. This frees developers to focus on core product innovation while reducing operational overhead, risk, and time to market.

View our Build vs Buy comparison chart for the full list of considerations.

Conclusion

Webhooks are essential for delivering real-time, event-driven experiences that modern applications and customers demand. They power automations, reduce infrastructure load, and increase product extensibility,  helping unlock more value for customers and for your business. However, while building webhooks in-house may seem simple at first, it quickly becomes a major headache for product and engineering teams, as the complexity and general upkeep takes more resources than expected. A third-party solution like Svix takes care of all of this complex infrastructure out-of-the box, so your team can focus on your core product instead of maintaining webhook infrastructure. It's the difference between spending months (or years) building in-house and trying to get it right vs. having a battle-tested solution up and running in days.

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