A-Sleep "World's No.1 Sleep Tech Expertise... Making Everyone Sleep Well Worldwide"

Interview with Lee Dongheon, CEO of A-Sleep
Faced crisis early this year due to sluggish commercialization
Overcame crisis and leaped forward through "selection and concentration"
"Will surpass breakeven point this year"
"Plan to create 'Sleep Assistant' in collaboration with OpenAI"

"We will take our world-class sleep measurement technology global. By revealing the invisible aspects of sleep, we aim to play a role like the 'semiconductor of sleep tech,' enabling diverse applications."

Lee Dongheon, CEO of A-Sleep, is being interviewed by Asia Economy at his company in Gangnam-gu, Seoul. Photo by Younghan Heo younghan@

A-Sleep was founded in 2020 by six members who met in a research lab at the Korea Advanced Institute of Science and Technology (KAIST), including CEO Lee Dong-heon, Chief Technology Officer (CTO) Hong Jun-gi, and Head of Product Goo Yoon-pyo. Since then, it has rapidly grown to be recognized as a leading startup in South Korea's sleep tech sector. A-Sleep’s ‘A-Sleep Track’ solution analyzes users’ breathing sounds using a smartphone microphone. This allows for easy assessment of sleep quality by analyzing sleep stages and other factors.

The foundation of sleep measurement is polysomnography. However, it is inconvenient as patients must wear multiple devices overnight in a hospital. To replace this, technologies using smartwatches to track heartbeats have emerged. But A-Sleep focused on 'sound.' CEO Lee explained, "Brainwaves that show sleep change in real time, but heartbeats change with some delay. We found that breathing sounds are actually closer to brainwaves." They collected breathing data from thousands of polysomnography tests and also gathered environmental noise data that needed to be filtered out.

Based on this, last year, CEO Lee explained, "In a sleep measurement performance test conducted by Stanford Medical School, Sleep Routine outperformed 11 other smartwatches and sleep measurement apps." The sleep apnea diagnostic support medical device 'ApnoTrack,' developed using this technology, received approval from the Ministry of Food and Drug Safety. Famous venture capitalists (VCs) such as Kakao Ventures and Samsung Venture Investment have invested, and global big tech companies leading AI trends like OpenAI and SoftBank have also shown interest.

However, in January, A-Sleep was embroiled in controversy with rumors of CEO Lee Dong-heon being replaced. The growth in profitability could not keep pace with technological advancement. Conflicts surfaced inside and outside the company due to differences in business direction. CEO Lee reflected, "Funds were running low while the organization was becoming bloated, which led to internal distrust."

A-Sleep originally pursued hardware product development alongside software products embedded in smartphones. However, unlike the rapidly commercialized software, hardware development continued to face difficulties. CEO Lee said, "Costs surged to the point where we were making lighting products to sustain the hardware business," leading to conflicts among founders over business direction and concerns about A-Sleep’s sustainability among investors.

To focus on what he does best, CEO Lee decided to stop hardware development and go all-in on software. The staff size, which had reached 70, was reduced to about 30. Although research and development (R&D) personnel were significantly cut, this was mainly hardware-focused, and the core software-related workforce was largely retained. The founders’ separation was also smooth. CEO Lee explained, "I acquired shares from other founders to become the overwhelmingly largest shareholder with 40%, and CTO Hong and Head Goo hold 15%, securing a majority stake." He added, "Despite difficulties, we received investments and surpassed a corporate valuation of 100 billion KRW."

Lee Dongheon, CEO of A-Sleep (center), Koo Yoonpyo, Head of Product (right), and Hong Junki, CTO, are sitting on a bed in the company's showroom in Gangnam-gu, Seoul, demonstrating the sleep application developed by the company. Photo by Younghan Heo younghan@

This year’s goal is to break even. CEO Lee said, "We were seen as a company with technology but no profits," adding, "It is certain that we will surpass the monthly break-even point within this year, and we expect to turn an operating profit next year." Despite the crisis, trust based on technology prevented client loss. Various companies such as SK Telecom, KB Healthcare, and Kyungdong Navien are turning to A-Sleep to incorporate the 'science of sleep' into AI services and sleep mats.

CEO Lee emphasized, "As the number of clients continues to grow, we already have contracts with over 30 companies, and we plan to increase B2B launched products to 10 within this year. If we estimate sales of 20 to 30 million KRW per product, we can achieve stable monthly sales of 200 to 300 million KRW and generate consistent profits within this year." He expressed confidence that as the client base grows, it will be possible to build a diverse ecosystem including temperature and humidity control for better sleep and lighting that wakes users at optimal times, stating, "A-Sleep can become the hub of sleep tech."

The next goal is overseas expansion. "SoftBank approached us first after seeing our technology abroad," he said, explaining plans to enter Japan through a partnership with SoftBank and to directly enter the U.S. market to find partners. A-Sleep is also collaborating with OpenAI, led by Sam Altman. CEO Lee stated, "A-Sleep is an AI company. We aim to create a personalized AI sleep assistant that analyzes sleep data using large language models (LLM) to advise and help users understand how well they slept and how to improve their sleep habits."