The stock market sell-off has knocked a lot of value off of many high-quality companies in 2022. The technology sector has been hit particularly hard, with the Nasdaq 100 index down 24% for the year, placing it in bear market territory.

But the blueprint for navigating a volatile market includes taking a long-term focus, which can help to smooth out the noise. In fact, putting money to work right now could reap significant rewards by 2030 if investors stick with quality stocks.

DigitalOcean (DOCN 3.30%) and Duolingo (DUOL 3.64%) are worth under $5 billion today but have the potential to climb to $10 billion by the end of this decade based on their unique business opportunities. Here's why. 

DigitalOcean: Implied upside of 127%

DigitalOcean is a provider of cloud computing services, which means it competes with trillion-dollar giants like Amazon and Microsoft. By comparison, DigitalOcean is a minnow because it's worth a mere $4.4 billion, but it has carved out a niche in the cloud industry that is of a lower priority to the larger players. 

The company focuses on serving businesses that have less than 500 employees or are even in the start-up phase. It has amassed 623,000 of these customers so far, who are spending a record-high $68.90 on average every month. 

DigitalOcean offers a range of solutions like website and video streaming hosting, and even platforms for software and game development. To cater to its target market, it competes with cloud giants by providing cheaper prices, a simple user-friendly dashboard, and thousands of items of educational material to give customers the best chance of success.

DigitalOcean's stock is down 68% from its all-time high, and it actually traded above a $10 billion valuation less than a year ago. The company has generated $462.2 million in revenue over the last four quarters, which places its stock at a price-to-sales ratio of 9 -- close to the cheapest it has ever been since listing as a public company in March 2021. 

DigitalOcean estimates that its segment of the cloud market will be worth $72 billion this year and could double to $145 billion by 2025. It means the company still has a long runway for growth, especially since those figures are a subset of the broader cloud industry, which could be worth over $1.5 trillion by 2030. 

Duolingo: Implied upside of 153%

Duolingo is a unique provider of digital language education. It's a mobile-first platform, and its success stems from its game-like features, which turn the learning experience into a form of entertainment. It even includes a competitive leaderboard and a social networking aspect to engage with friends and family who are also learning. 

Duolingo has been downloaded over 500 million times and boasted 49.2 million monthly active users in the first quarter of 2022. The app is free with a paid subscription option to unlock additional features, which 2.9 million users are utilizing. That's a 60% jump in subscribers compared to the same time last year. 

The company only introduced subscriptions in 2018, and it has already rocketed up the rankings to become the highest-grossing education app in both Alphabet's Play Store and Apple's App Store. For the 2021 full year, Duolingo generated $250.8 million in revenue, and its guidance suggests that figure could grow by up to 42.7% in 2022, to $358 million.

On that note, the company is likely still very early in its growth phase. It estimates there are 1.8 billion people learning a foreign language around the world, and there's a rapid shift in the space to digital platforms. Since Duolingo is already the leader in this segment, it's in a great position to capture a large slice of what could be a $145 billion annual opportunity by 2030. 

Duolingo's stock has fallen by 51% from its all-time high amid the broader tech sell-off, and its current valuation stands at $3.9 billion. It traded at close to $8 billion less than a year ago, and given the magnitude of the company's addressable opportunity, its growth should only accelerate over the next eight years. If it reaches the $10 billion level, investors who buy it now would enjoy an attractive return of 153%.