Coalesce turns CI from a blocker into a trusted safety net with RWX

About

Coalesce gives enterprise data teams one governed platform to build, manage, and validate the pipelines that power analytics and AI. Backed by $81 million in funding, Coalesce is trusted by today's leading enterprises, including Caesars Entertainment, Denny's, Houlihan Lokey, and TotalEnergies.

Challenge

Slow, unreliable CI hindered team confidence and development velocity

As a platform built to assist today's leading businesses in creating and managing robust data pipelines, Coalesce requires CI that can keep pace with its product promise. But as the company quickly scaled its engineering team and test suite, existing GitHub Actions workflows couldn't deliver on that need.

At the time, even a successful end-to-end run in GitHub Actions would take 45 to 60 minutes to complete. When flaky tests or GitHub-side infrastructure failures interrupted a run, developers often had to replay the pipeline, pushing feedback to well over the two-hour mark. It didn't take long for Mike McCune, VP of Engineering at Coalesce, to realize that this necessary rigor was introducing long, unpredictable pauses in the development loop that his team couldn't afford.

“There's no arguing the value of the tests, but everybody was so unsatisfied because of how slow they were,” Mike shares. “Our developers couldn't get on to new work until they'd spent half a day trying to get their change merged.”

CI friction also began to shape the team's appetite for innovation. With every large change carrying the prospect of another lengthy turnaround, the team narrowed scope, avoided bold refactors, and favored lower-risk paths. “It created an environment where the team was very risk-averse,” Mike shares. “Rather than shipping big, bold changes, we were more focused on not breaking anything.”

While Mike took several actions to address these blockers, such as optimizing Coalesce's tests and moving GitHub Actions execution to Depot, they didn't materially improve speed or reliability. That realization shaped his search. Rather than looking for another CI/CD platform promising faster feedback loops, he needed a solution that would fundamentally change the developer experience at Coalesce. After discovering RWX, Mike knew its self-optimizing CI workflows and intelligent test caching were the ideal fit.

Solution

RWX helps Coalesce close the gap between writing code and validating it

Getting started with RWX was a swift and collaborative process. Its engineers worked alongside Mike's team to translate workflows, configure run definitions, validate the converted pipeline, and work through implementation blockers as they surfaced. Within three weeks, Coalesce had its core CI workflows operational.

“RWX worked with us to run the proof of concept and convert our workflows with hardly any friction,” shares Mike. “We weren't learning the platform in isolation; we were building a working system with the people who understood it best.”

RWX represents Coalesce's build and test workflows as a directed acyclic graph of tasks and dependencies. Independent tasks run concurrently, while downstream tasks wait only for the filesystem state they need. RWX automatically caches each task according to its definition and content inputs. When those inputs remain unchanged, the platform restores the prior output instead of recomputing it.

That architecture fundamentally changes the unit of CI. Instead of treating every pull request as a reason to replay the same end-to-end pipeline, RWX enables Mike's team to carry forward valid task outputs and rerun only the tasks invalidated by new inputs. CI becomes responsive to the actual change rather than imposing the same fixed penalty on every change. For Coalesce, that means larger changes no longer automatically create proportionally larger waits or force engineers to repeat work the pipeline has already validated.

Mike has already used this more efficient loop to strengthen controls around larger changes. Coalesce added test coverage impact metrics to every pull request, giving Mike and the engineering team visibility into whether a change preserves their coverage baseline before it merges. As AI increases the volume and size of some pull requests, comprehensive tests and visible coverage signals enable the team to evaluate larger changes on evidence rather than size alone.

Crucially, the migration broadened CI ownership. Not only do more developers understand how Coalesce's pipelines work, but RWX documentation and command-line access offer direct paths to inspect and maintain test results. RWX's prepackaged agent skills also help the team build and maintain CI definitions. Meanwhile, CI health flows into Datadog, where Mike can see individual tests begin to flake and address them before instability spreads across the suite.

CI no longer dictates the size of change Coalesce is willing to make. It has become a shared, observable capability that enables Mike's team to pursue more ambitious work without lowering their quality bar.

Results

Streamlined, efficient, and scalable CI that developers actually trust

With RWX, Coalesce transformed CI into a dependable validation layer for larger, better-tested changes. Developers now move more code through review, Mike seamlessly tracks coverage and flakiness, and the organization keeps pace with AI-assisted development without lowering its quality bar.

Since partnering with RWX, Coalesce has cut CI costs by 50% compared to GitHub Actions, now runs 15 parallel tasks and 40 test shards per pipeline, and achieved 4x faster CI feedback loops.

Looking ahead, Mike is planning to consolidate multiple Coalesce repositories into a monorepo, confident that RWX can handle more complex workflows and parallel pipelines without friction.