SignalFx

Market position

SignalFx was positioned in the cloud monitoring, observability, and application performance management market, competing against legacy APM vendors. Splunk described the acquisition as making it a leader in observability and APM across cloud-native and on-premises environments, and it was Splunk's largest acquisition to date at $1.05 billion, exceeding its $350 million purchase of Phantom and $120 million purchase of VictorOps.

Sources attribute SignalFx's differentiation to its massively scalable streaming architecture, which split metric data into separate metadata and time-series streams over a publish-subscribe bus, and to SignalFlow, its analytics language for real-time computation on streaming metrics. At acquisition, Splunk highlighted real-time streaming analytics and a NoSample architecture for distributed tracing as highly differentiated features relative to legacy APM solutions.

Technology

The platform used a massively scalable streaming architecture in which metric data was split into two streams — metadata and time-series values — routed through a publish-subscribe bus and processed by an analytics language called SignalFlow. It ingested metrics and traces from infrastructure, applications, microservices, containers, and serverless functions, and applied advanced analytics and data-science-directed troubleshooting for real-time alerting and root-cause identification. A "NoSample" architecture was used for distributed tracing.

Go-to-market

SignalFx sold its SaaS monitoring platform directly to enterprises operating cloud-native, on-premises, and hybrid application environments. Before the acquisition, SignalFx and Splunk had collaborated on serverless monitoring, particularly around open-source instrumentation for AWS Lambda.

Enterprises and IT/DevOps teams running cloud-native, on-premises, and hybrid applications at scale. Named customers included Athenahealth, Chairish, Ellie Mae, Carbon Black, Kayak, Shutterfly, Sunrun, and Yelp.

Geography

Headquarters in San Mateo, California, United States. Sources do not describe offices outside the United States.

History

SignalFx was co-founded in February 2013 by Karthik Rau and Phillip Liu and was originally known as SignalFuse. It raised an $8.5 million Series A from Andreessen Horowitz, with Ben Horowitz joining the board, and a $20 million Series B in 2015 led by Charles River Ventures with participation from Andreessen Horowitz, at which point Devdutt Yellurkar joined the board. The company rebranded from SignalFuse to SignalFx and emerged from stealth on March 12, 2015 with $28.5 million in total funding reported at the time. In May 2018 it announced a $45 million Series D led by General Catalyst with participation from Andreessen Horowitz and Charles River Ventures, and in June 2019 a $75 million Series E led by Tiger Global Management, bringing total funding to $179 million. Splunk announced an agreement to acquire the company on August 21, 2019 for $1.05 billion, and the transaction closed on October 2, 2019. SignalFx became part of the Splunk Cloud Platform and, after Cisco completed its acquisition of Splunk in March 2024, came under Cisco's ownership.

Risks & controversies

No controversies are reported in the available sources. The principal structural change is loss of independence: SignalFx ceased to operate as a standalone company following the October 2019 Splunk acquisition, and subsequently passed to Cisco ownership in 2024. One aggregator source (Signalbase) contains inconsistent data, listing total funding of $75.0 million and an employee count of 5, which conflicts with the $179 million total funding and 200+ employee figures reported elsewhere.