2025

Part 1

Belated update. Yes, it’s been five years, can’t believe it myself. What’s the “delta” for the last three years that flew by too fast?
Certain things haven’t changed much. We are still under the “dual mandate” — OSS server, SDKs (clients), CLI, and a whole bunch of other peripheral software, plus a cloud service where we charge customers for running and managing the invisible infrastructure so that they don’t have to. My focus continues to be primarily on the cloud side.

At the same time, obviously, everything has changed — some things even multiple times. We went through COVID with its obligatory work-from-home setup, only for many companies to start imposing, some more gradually than others, return-to-office policies. I interviewed a number of candidates recently who moved away from major tech hubs during COVID and had to leave their jobs because of the RTO push. We are still fully remote.

Most of the Big Tech companies went through rounds of mass layoffs — a tectonic shift from the previous 20 or so years of competing for talent and outbidding each other in offers. Startups suddenly became much more attractive for Big Tech employees who were previously reluctant to take the risk of leaving their well-paid jobs. At the same time, startup founders faced the funding drought starting in late 2021 and early 2022 caused by interest rate changes. Many had to close or fire-sell their ventures where just a couple of years earlier, cheap money seemed unlimited.

Product

Developers choose Temporal for its programming model. They experience it in a language of their choice via Temporal SDKs. We started with two languages. Now we support seven: Go, Java, TypeScript, Python, .NET, PHP, and Ruby. Four of them are built on the same Core SDK written in Rust. No, we still don’t have an official Rust SDK.

We started Temporal Cloud by hosting the OSS Temporal Server with an added layer of security and multi-tenancy. The original value proposition included that, plus general operational concerns such as monitoring, alerting, configuration, upgrades, and scale. We’ve been investing along several dimensions since then and are now running the fifth-generation Cells (Temporal Cloud “clusters”).

Building a custom storage layer between the server and database to absorb reads and coalesce writes was one of the first bold undertakings. Rolling it out to production over the course of 2023 gave us a significant increase in reliability, performance, and scalability compared to the vanilla OSS server. Another major investment was making it possible to incrementally add multiple databases to a running server. With these improvements, the scenario I mentioned in one of my previous posts, a major customer needing to increase their already outsized traffic level up to 10x for a day, became routine. At the end of 2021, a day like that was a big deal for both companies, with teams of engineers monitoring the system, communicating live, and taking action. The subsequent occurrences became increasingly “boring” and turned into non-events.

On the authentication/authorization dimension, we went from initially supporting only mTLS and Google SSO to adding API keys, service accounts, SAML, SCIM, and a bunch of other features critical for enterprise — and not only enterprise — customers.

We started with prospective cloud customers filling out a form, getting contacted by our sales team to complete the paperwork, and then creating an account on their behalf. Embarrassing. Now, we have a complete self-signup process that guides prospective customers along the path, with a full PLG motion behind it. When we opened up Temporal Cloud to the world, we were missing a number of table-stakes features. At the time, I called the bar we had to meet a “reasonable cloud service.” I believe we passed this milestone 12–18 months ago.

I like that we don’t play licensing games (our OSS is under the MIT license) and instead extend and enhance it with proprietary features to differentiate our cloud offering.

We launched Temporal Cloud in 2022 with support for AWS only. We added GCP in 2025 and are working on bringing in Azure, the last of the big three providers. Even though support for Kubernetes clusters across them is similar, most of the integration effort goes into their disparate security and resource hierarchy models, differences in networking, and subtle behavioral differences in their seemingly compatible APIs — for example, GCS vs. S3. Recently, we’ve been chasing GCP load balancers mysteriously ghosting a fraction of the connections. Support for hosted Elasticsearch is another headache — only AWS has it, but in the form of OpenSearch, their fork of ES from before Elastic changed its license.

AI

The agentic AI “storm” turned into a sudden tailwind for Temporal. The very nature of such applications — being stateful, depending on a significant number of semi-reliable API calls to external services, and taking seconds to minutes to execute — made code-first Durable Execution a compelling programming model for this fast-moving, massive herd. While there are still some rough edges for AI use cases in the near term (such as payload and history size limits and required determinism of workflow code), the immediate benefits — high-velocity development of much more reliable code in the language of your choice, guaranteed scalability, and unparalleled visibility into execution for debugging — keep bringing AI-focused companies to Temporal. More traditional businesses that are scrambling to integrate AI into their systems do the same. I was told that as of late 2024, out of the top 20 AI companies, only two were aware of Temporal — and now, 16 of them already run Temporal-based apps.

Nexus

This year we launched the initial version of Nexus, an open-standard-based protocol for APIs that may take arbitrarily long to complete. I think of it as a great frontend layer for Durable Execution. But the protocol itself is implementation-agnostic. One could implement it using more traditional tools and approaches, for example, within the paradigm of event-driven architecture. The idea was conceived in the early days of Temporal. We started talking about it publicly in 2022, only to do nothing for another year due to other priorities.

We believe that Nexus is an immense opportunity to integrate systems and services in a new, powerful way. Nexus deserves a dedicated post, and I’m contemplating a conference talk about how the combination of Durable Execution and Nexus could define a major evolution of the Microservice Architecture. I understand this is a very bold statement, but sometimes you have to shoot for the Moon.

(To be continued in Part 2)