What founders can learn from an astrophysicist-turned-climate-tech entrepreneur navigating the chaos of a startup.
Since co-founding Brownee, a B2B climate-tech platform that helps businesses take real sustainability action, in 2022 Jill Rathborne has been wearing a lot of hats - CTO, CPO, CDO, and AI lead. Three years later, Brownee has gone through ups and downs, as startups do. They've found investors and customers, built a product and created revenue. And Jill? She’s navigating the chaos with grit, humility, and a learner’s mindset.
“It's been quite a journey, and it is only getting more exciting with a new direction aligned to our core customers!”
Jill joined the 7th Cohort of the Women in Climate and Energy Fellowship, to share her founder journey and her top five lessons for founders navigating the windy path of an early-stage startup.
1. It Takes a Village - So Build One
It’s not just OK to ask for help. You have to.”
Jill’s first startup, founded during COVID, didn’t survive. One of the key reasons? A lack of community. There were no events, no networks, and their mentors were mostly friends who didn’t challenge their thinking. When founding Brownee, Jill made a different choice: plug into every opportunity. From accelerators like EnergyLab’s Climate Solutions Accelerator and EnergyLab’s Charge Program to mentorship programs and founder meetups, she prioritises connection, even when it takes time away from "the real work."
Founders often think they don’t have time to build a network. Jill’s advice? "You can’t afford not to. A lot of the time, that extra hour [of networking] is more beneficial than anything else that I could have done in that hour." A single mentor conversation could save you a month of wrong turns.
2. Your biggest asset is your ability to learn, fast!
“Founding a startup is all about learning faster than the wheels can fall off…..because they are always falling off”
Coming from 20 years in astrophysics, Jill has deep technical expertise and a rigorous approach to problem-solving. But stepping into the founder role demanded far more – from driving product development and shaping AI architecture, to leading UX design, building teams, and navigating the complexities of early-stage business strategy.. Her advice? Embrace the chaos and learn just fast enough to stay ahead of the breakdowns.
You don’t need to be an expert in everything, but you need to be quick to learn and open to asking for help. ‘It’s important to get advice as much as you possibly can!’
“Founding a startup is all about learning faster than the wheels can fall off…..because they are always falling off”
3. Get Comfortable with Chaos (and Failure)
“In five years, we’ll know what the right path was. Today, we just have to make the best decision with the info we’ve got.”
As a scientist, Jill was used to data and clarity. Startups gave her neither. Instead, she had to adapt to making decisions with incomplete information, juggling urgent and important tasks, and facing the possibility of failure.
‘There’s a constant tension between what’s important and what’s urgent and you often need to make decisions with very little information’
4. You Can Only Pick Two: Good, Cheap, or Fast
“You can do it high quality and fast—but it won’t be cheap.”
In her role as CTO, Jill leans on the ‘constraints triangle’ to guide product decisions. In the early days, when building Brownee’s MVP, she had to make tough calls about what to prioritise between quality, speed and cost. "You want to do it all,l but you can’t, especially within the constraints of an early stage startup."
Don’t fall into the trap of perfectionism. The MVP doesn’t need to be everything, it needs to be viable.
“In five years, we’ll know what the right path was. Today, we just have to make the best decision with the info we’ve got.”
5. Your Co-founder Relationships Are Everything
‘The relationship you build with your co-founders is one of the most critical things’
Jill’s seen how quickly things can fall apart when values and expectations aren’t aligned and how common founder separations are. She’s learned to have the tough conversations early—about values, communication, decision-making, and what happens if things don’t work out. She’s found that the best thing you can do is set clear rules before you think you’ll need them.
“The first thing we did was a values exercise, then we used 50 questions to explore with a potential co-founder. I highly recommend it.”
Startups live and die by co-founder dynamics. Build the relationship before you build the product.
Final word
Jill Rathborne’s journey - from astrophysics to climate tech and many twists and turns in between - is proof that nonlinear paths make powerful founders.
Her message to fellow founders?
“It’s hard. It’s chaotic. But it’s worth it. Just keep learning faster than the wheels fall off.”
Want to follow Jill and Brownee’s journey? Follow Jill on LinkedIn and visit the Brownee website.
Interested in joining EnergyLab’s Women in Climate and Energy Fellowship or our Climate Solutions Accelerator? Head over to our programs page for more information.
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