Interest in artificial intelligence continues to surge globally, but genuine ASX AI shares remain surprisingly rare. That scarcity could create opportunities for investors willing to look beyond the market's obvious winners. A handful of lesser-known ASX AI shares still offer the kind of catalysts, operating leverage, and re-rating potential that could drive outsized returns. Here are two names increasingly catching investor attention. Image source: Getty Images Macquarie Technology Group Ltd (ASX: MAQ) First up is Macquarie Technology. This ASX AI share is rapidly emerging as one of the clearest "picks and shovels" plays on the AI boom. As artificial intelligence adoption accelerates, demand is exploding for data centres, cloud infrastructure, cyber security, and sovereign hosting solutions. These are exactly the areas where Macquarie Technology is investing aggressively. In March, the company secured a $200 million hybrid investment from the government-backed National Reconstruction Fund Corporation. The funding will help accelerate development of sovereign cyber security and cloud services and AI infrastructure for government agencies and defence and critical industries. Management plans to draw down the first $100 million by June 2026 and the second tranche by March 2027. Unlike many speculative AI stocks, Macquarie Technology already generates meaningful earnings and has very visible demand drivers. The ASX AI share has now delivered 20 consecutive half-years of operating income growth, an impressive track record in any market environment. As more data centre capacity comes online and utilisation rates rise, earnings could expand rapidly. If the market begins valuing the company more like established data centre operator NextDC Ltd (ASX: NXT), investors could see significant upside from current levels. Appen Ltd (ASX: APX) Then there's Appen. This is unquestionably the more speculative of the two ASX AI shares, but it may also carry the greatest upside potential. Appen provides training data used by artificial intelligence models, placing it directly in the centre of the generative AI ecosystem. After several difficult years, there are finally signs the business may be stabilising. For the March quarter, Appen reported revenue of $54.8 million, up 9% from the prior corresponding period. That marks an encouraging shift after a prolonged period of declining sales. Profitability also improved. Underlying EBITDA came in at $1 million, compared to a $1.5 million loss a year earlier. The strongest momentum is clearly coming from China. Revenue in the region surged 88% to $34.9 million, driven by growing demand tied to generative AI projects. The division exited the quarter with an annualised revenue run rate above $144 million. Outside China, however, conditions remain challenging. The Appen Global segment saw revenue tumble 37% and posted an EBITDA loss of $3.1 million, reflecting the uneven nature of project-based work. Even so, after the share price collapsed almost 90% over the past five years, expectations are now extremely low. That creates an interesting setup. If demand for high-quality AI training data continues recovering or if Appen secures new strategic partnerships, even modest operational improvements could spark a sharp market re-rating.