rrweb

binator.com/item?id=46708055). How it works: - one S2 stream per browser session - large rrweb events (like a full snapshot) get framed across multiple binary S2 records and reassembled on read - active sessions are tailed with an S2 read session, and bridged to the browser over SSE - session listing relies on stream names encoding reverse timestamps, as S2 returns a lexicographic order listing - relying on fencing tokens so a stopped session can't be written to again by a late recorder - retention and GC are handled via S2 stream config, so no background job needed Curious to hear from folks on the tool or the stream-per-session model!

rowing. This is where Highlight.io comes in: our product bridges the gap between client and server to give you a holistic view of your entire application. At its core, Highlight.io has three main “products”: Session Replay, Error Monitoring, and Logging. The novelty here is not in each product but in how they are connected. For example, in Highlight.io it’s very easy to click from a given error to the associated user session where it is thrown [4], and from a given error, you can easily inspect all of the logs that fired leading up to it. Ensuring that all of our products work together seamlessly with little to no effort is a core principle of our product strategy. If you’re using a common framework [5], for example, we’ll automatically link your frontend sessions with backend errors and logs. No agents, configuring facets, or anything else, It just works. We depend on several open source projects that help us move quickly. OpenTelemetry (OTEL) [6] is one of them, which helps us with maintainability, i.e. for every language that we support, we only maintain a thin wrapper around its respective OTEL SDK. OTEL is also a great way to enable the community to contribute, and we’re already seeing traction in this space (ie. an open source contributor built a wrapper for a Java SDK [7]). rrweb [8] is another project we leverage heavily for our session replay product. It drives our ability to record and replay the DOM to visualize user flows in the frontend. We’ve had the privilege to work closely with the rrweb team to ship improvements, and we’re now actively sponsoring the project [9]. ClickHouse [10] has recently become a loved database on our team, as we historically used Opensearch for search-heavy workloads and started to hit growing pains with ingest throughput. We recently rolled it out for our logging product [3] and plan to replace our sessions and errors (and upcoming tracing work) with the database as well. From a business perspective, Highlight.io is open source under the Apache 2.0 license, and we make money with our hosted product [11]. For the hosted product, you can set billing caps for each offering and we don’t charge for seats. At this point, we have 100+ companies paying for our product (some of which are large enterprises), and thousands of sole developers use Highlight.io every week. On our roadmap [12] for the future includes metrics, tracing, release management and more. We also are launching several updates this week on our launch week page [13]. Overall, we’re excited to be sharing Highlight.io with the world, and Vadim and I are particularly excited to get some feedback from the HN community. Please give us a test-drive at https://app.highlight.io and let us know what you think. We would love to learn about what you wish you had in an observability product as well as any other experiences and ideas in this space. We look forward to hearing from you! 1: https://github.com/highlight/highlight/blob/main/LICENSE 2: https://news.ycombinator.com/item?id=34897645 3: https://news.ycombinator.com/item?id=35643255 4: https://youtu.be/EvGsmbt0F7s?t=65 5: https://highlight.io/frameworks 6: https://opentelemetry.io/ 7: https://github.com/highlight/highlight/pull/4812 8: https://github.com/rrweb-io/rrweb 9: https://github.com/rrweb-io/rrweb#gold-sponsors- 10: https://clickhouse.com/blog/overview-of-highlightio 11: https://highlight.io/pricing 12: https://www.highlight.io/docs/general/roadmap 13: https://highlight.io/launch-week-2

op app is written in JS (slowly moving to typescript here too) & use electron as underlying framework to support cross-platform needs. For mock server & collaboration features, we use Firebase as backend. Here are some popular use cases how people use Requestly - Stress testing frontend code by testing bad API responses, API failovers, latencies, testing with huge API responses, etc. (You create different rules inside Requestly and enable/disable as per use case) - Testing scripts directly on customer sites - Switching environments for APIs & scripts - Developing features when APIs are not ready - Modifying live websites (prospects) and demo their product directly on client’s website instead of an internal website (Applicable for SaaS products that integrate with JS) Overall, we’re quite new to the open source world and still learning how to run an open-source product & roadmap. We’d love the HN community to share their feedback on what we’re building and how can we improve. If there’s anything that they’d like us to build in the future, we’re all ears. Check us out at [requestly.io](http://requestly.io) and [github.com/requestly/requestly](http://github.com/requestly/requestly) to give us a shot [0]: Mock Server - https://app.requestly.io/mocks [1]: Sample Session - https://app.requestly.io/sessions/saved/iedsEivORxdLTcBiNcBA [2]: https://github.com/rrweb-io/rrweb [3]: https://chrome.google.com/webstore/detail/redirect-url-modif... [4]: https://requestly.io/downloads

bine that data with the `window.performance` api's notion of network requests to ensure we capture all requests (even ones that happened before our monkey-patch had time to apply), as well as to get precision timing data. Happy to give more detail about parts of our stack if you're interested!

panning across both the frontend and backend. The main issues were (1) if a customer complained about a problem, it was hard to reproduce the issue without asking for a screen-share or jumping on a video call; and (2) when viewing errors caught by tools like BugSnag or Rollbar, understanding the triggered code path required stitching together logs, errors, and trace; all from different sources. Highlight.io is completely open source and written in Go and Typescript. To build the replay capability, we use an open source project called rrweb [2] and have worked closely with their team to add support for features like canvas recording, shadow dom recording, and more [3]. Beyond that, we use the OpenTelemetry spec for our SDKs [4], which has made it pretty straight forward to support several languages, even with our small 4-person engineering team! Our product is completely self-serve at app.highlight.io. Installing it is as easy as a npm/yarn import and installing the backend sdk of your choosing. In addition, given the privacy-centric nature of session replay, we also offer the option to self-host [5]. Highlight.io currently makes money off of our hosted offering, and our self-hosted deployment is completely free. We’re also toying with the idea of an “enterprise” self-hosted deployment, similar to gitlab’s billing model, and thoughts from the community on this front would be appreciated! And as far as what’s next for us: Our customers are asking to render logs and traces on a highlight.io session (and vice versa), and we’re excited to be going deeper into a developer’s debugging stack. The long term goal is to build a platform that connects replay, errors, logs and more so that engineers can “playback” the full state of a web application. Overall, we’re quite new to the open source scene and would love the HN community to share their feedback on what we’re building. If anyone has opinions on where we’re going, or what they’d like to see in an open source monitoring product, we’re all ears. Check us out at highlight.io and at github.com/highlight/highlight to give us a shot. [1]: https://www.highlight.io/docs/getting-started/frontend-backe... [2]: https://github.com/rrweb-io/rrweb [3]: https://highlight.io/docs/general/product-features/session-r... [4]: https://opentelemetry.io/docs [5]: https://www.highlight.io/docs/general/company/open-source/se...