The first version had three engineers and a division of labor. Suresh Kondamudi built the database and machine-learning technology. Anand Jain stitched together middleware, servers and production operations. Sunil Thomas, already a veteran technology chief, drew the shortest straw or perhaps the most revealing one: he became the UI and HTML person. His job was to build the dashboard that customers would actually see.
This was 2013. The company was called WizRocket, the name of a science-fair contraption, and its founders had left senior jobs at Network18 in Mumbai because the work had become slow and, by their account, stopped being fun. All three had led engineering organizations. Now they were back at laptops, turning a recurring irritation into software. Marketers constantly asked technical teams to dress up a website, change an app, or run a holiday campaign. Insight sat in one system. Action waited in another. The engineers became the human bridge.
The problem looked larger than another campaign tool. Consumer businesses could spend heavily to acquire people, then watch them disappear after a download or a first purchase. Thomas and his partners chose retention as the organizing idea. It lacked the cocktail-party sparkle of growth, but it possessed the agreeable quality of mattering.
“The biggest light bulb moment was that no one, no company was taking a holistic view of solving the user retention problem.”Sunil Thomas
A rejection worth keeping
The founders applied to Y Combinator and reached an in-person interview. They were rejected. The criticism was precise enough to be useful and uncomfortable enough to require time: the product seemed appropriate for businesses such as Amazon and Netflix, where one customer produces a thick history of behavior, but not obviously for the much larger universe of brands with briefer encounters.
Thomas has said it took the team a month to understand what the interviewers meant. Once they did, they threw away the existing code and started again. This is the sort of detail that disappears from tidy startup histories, which prefer a straight arrow from inspiration to scale. Here, the arrow doubled back and ate a chunk of the calendar.
They kept the problem and changed the answer. BookMyShow, the ticketing business, became an early customer and sent real activity through the beta platform. That traffic exposed questions no whiteboard could answer: how to analyze events at scale, how quickly a segment could update, how a useful insight could become a timely message. CleverTap hired customer-success staff before it built conventional sales and marketing teams. The first customers were less an audience than an additional product department.
For roughly two years, the company faced inward. Commercial selling did not begin until the middle of 2016. The delay was not an extended launch party. The founders were working on the less photogenic parts: gathering behavioral data, processing it quickly, making it available for segmentation, and connecting analysis to communication. The eventual product joined behavioral analytics, small audience segments, automated journeys and messages across push notifications, email, SMS and in-app channels.
There was an attractive stubbornness to the schedule. A company built to improve retention first had to retain its own conviction.
The three-market education
Thomas did not arrive at that first dashboard by the usual founder shortcut of being very young and therefore gloriously unencumbered. He had already spent years inside substantial technology organizations. A computer science engineer trained at the University of Mumbai, he worked earlier in his career at Tata Consultancy Services, Microsoft and Hewlett-Packard. His first entrepreneurial post was chief technology officer of Zephyr Software, which InfoSpace acquired in 1999.
At InfoSpace, he climbed through engineering management with almost suspicious neatness: senior development manager, director, senior director, vice president, then chief technology officer in 2008. He worked in Seattle until 2009, when he moved back to India. His explanation was both personal and strategic. He believed the United States, China and India were the critical places to sharpen technology instincts; he had learned in one and wanted a serious chapter in another.
Network18 supplied that chapter and introduced the future founders to one another. Thomas later moved to Silicon Valley in 2014, not merely to sell but to collect product judgment from a mature software market. CleverTap was born in Mumbai, developed between India and America, and tested early in mobile-first economies where devices, networks and user habits varied wildly. When Thomas later observed that Asia was “mobile-first and massively growing,” it was less a slogan than a description of the laboratory.
Thomas rises through InfoSpace's engineering ranks and becomes CTO.
He leaves Seattle for India and joins Network18.
Thomas, Jain and Kondamudi found the company that becomes CleverTap.
CleverTap launches publicly at TechCrunch Disrupt.
Thomas becomes executive chairman; CleverTap acquires Leanplum and raises its Series D.
He returns to the CEO role.
Those crossings mattered. In the East, engagement was already timely and phone-centered. In the West, marketing still leaned heavily on email. The platform had to serve both worlds without assuming that either one was the future in full.
The sandwich, the shuttlecock and the system
A technically fluent executive can easily become a ceremonial translator, wheeled out when a database needs dignity. Thomas has resisted the part. He calls himself a technologist at heart, writes about product choices, and reaches for decidedly nontechnical metaphors when talking about people. In one essay, a team became a sandwich: bread, fillings and spreads, separate ingredients whose value depends on structure and cohesion.
He enjoys Patrick Lencioni's management books because they deliver ideas as fables rather than manuals. His favored organizing tool, at least in a 2020 conversation, was Microsoft OneNote. The stack is pleasingly unfashionable: a story, a sandwich and a digital notebook.
Then there is badminton. Thomas plays competitively with his wife in tournaments around the San Francisco Bay Area. He has called it his favorite sport and written about what it teaches: preparation, partnership and the need to adjust while the point is underway. He also follows football, Formula 1 and cricket, a collection that covers patience, machinery and the occasional rain delay.
The sporting analogy is unusually apt for his company. CleverTap's proposition has always involved reading behavior and responding while the moment is still alive. Its founders revised the product after an accelerator interview, revised it again with early-customer data, and shipped updates every few weeks even as larger clients made change more complicated. A rally punishes the player who admires the last shot for too long.
Leaving the chair, then returning
In 2021, after eight years as CEO, Thomas moved to the executive-chairman role. The remit was strategic direction and innovation. The following year brought two large markers of scale: CleverTap completed its acquisition of Leanplum, expanding its reach in North America and Europe, and raised a $105 million Series D led by CDPQ. At that point the company said it served 1,200 brands in 100 countries across 10,000 apps.
He returned as chief executive in July 2024 after Sidharth Malik stepped down. A founder coming back to the main operating seat inherits a peculiar organization: it contains the memory of the thing he built and all the habits it acquired without him. The original three-person division of labor no longer applies. The underlying question does. How can a brand understand what a customer needs now and act before now becomes yesterday?
“The next breakout brands won't simply use AI features. They'll run on an AI-powered growth engine.”Sunil Thomas, looking toward 2026
Thomas now describes a shift from campaigns to continuous decisioning. In the older model, a marketer selects the audience, message, offer, channel and time, then sends the campaign. In the model CleverTap is pursuing, a business still defines the objective and guardrails, but an AI system continually chooses what should happen for each customer as context changes. The software moves from predicting a likely outcome to selecting a next action.
It is an ambitious technical loop: observe, decide, act, learn. It is also the old CleverTap idea with the waiting removed. Analytics and engagement began as separate rooms. The founders built a door between them. The latest plan is to make the door automatic.
What stays
Thomas has spent his career in systems designed for speed, yet his own story makes a quiet case for patience. A decade at InfoSpace preceded the founder chapter. Two years of inward product work preceded commercial selling. A rejection required a month of thought before it produced a rewrite. Even retention, his chosen problem, is simply patience measured in returning customers.
This does not make him cautious. Throwing away code is not caution. Leaving a CTO career, moving countries, acquiring a competitor and returning to a CEO job all involve appetite for disruption. The pattern is more specific: move quickly after the premise is clear, and be willing to slow down when the premise is wrong.
The dashboard Thomas built in CleverTap's first year was meant to make behavior legible. Thirteen years later, the company is asking software to act on behavior continuously. Between those points sit investors, acquisitions, thousands of apps and a great many notifications. The cleanest line through them is still the least glamorous word in the marketing dictionary. Retention asks whether the first promise was good enough to deserve a second encounter.
For Thomas, it has become both business model and biography. Careers, companies, customers, co-founders: the interesting work is not merely winning them. It is building something they have reason to stay with.