For some older people, just downloading an app or successfully navigating certain websites might seem like cause for quiet celebration.

But not for Shirley M. McKerrow, a retired business owner and politician from Darwin, Australia.

McKerrow, 84, revels in the thought of learning to develop those same apps and websites. Last year, she began taking free online coding lessons through Codecademy, an interactive platform that teaches programming languages, and was tutored along the way by her tech-savvy grandson.

She could hardly contain her enthusiasm: “I might use my newfound skills to create personalized, all-singing-and-dancing online birthday cards — in fact, all sorts of greeting cards for my family and friends. Maybe I could even graduate to making greeting cards personalized for businesses or for members of Parliament to send to their constituents.

“I have all sorts of ideas,” she continued, “but need to progress my skills a little further before I get too carried away.”

While millennials make up the bulk of those learning in-demand skills like web design, programming or digital marketing — the average age of students at coding boot camps, for instance, is just under 30 — some people old enough to be their parents or even grandparents are also acquiring these abilities.

Some, like McKerrow, are taking free lessons or video instructions online. (About a million of Code-cademy’s 45 million users globally are 55 or older.) Others subscribe to web-based courses or take classes at community colleges, universities or boot camps.

“To say there are ‘many’ might be a stretch,” said Jake Schwartz, a founder and chief executive of General Assembly, which offers technology and design training online and in 20 locations worldwide to corporations and individuals. “But they have been a welcome addition to class dynamics.”

Many older coders want to develop new skills to keep their jobs or to start second careers.

Some are looking for volunteer opportunities or hobbies in their retirement.

Nearly all who have gone through the rigors of trying to understand correct syntax, algorithms and other technical foundations also gain a sense of confidence and accomplishment, while maintaining and improving their mental acuity.

Liz Beigle-Bryant, 60, of Seattle credits the online classes she took in HTML and CSS code, the building blocks of the web, for helping her land a “dream job” recently as a document control coordinator at the public transit agency Sound Transit.

She expects to use these tools often in her new position.

“One of the big obstacles in a job interview when you’re older is that people think you’re inflexible and you can’t learn new things,” said Beigle-Bryant, who was laid off from her job as an administrative assistant at Microsoft in 2011.

The code lessons she took a few years ago, also through Codecademy, “gave me an edge,” she said. “I developed a confidence that I didn’t have before.”

The operators of many of the nation’s nearly 100 coding boot camps say the vast majority of students enrolled in immersive training programs, which usually last 12 to 15 weeks and cost about $12,000 to $15,000, find employment upon completion. (The most popular program? According to Course Report, a website that monitors this industry, it’s a Java- Script-focused “full stack,” which teaches all stages of software development.)

Older people have been part of these success stories, too, yet they are often hesitant even to get started.

“I think so many people are discouraged because they think they’re too old,” said Letta M. Raven, a tech support specialist for a payroll software company and a frequent speaker at women’s tech conferences. She has observed this reluctance among some conferencegoers and has even had it herself.

I was considered old in this industry,” said Raven, who is 42 and held many jobs, including pastry chef and artist, before settling into her current career. She was long interested in software development, but it wasn’t until two years ago that she enrolled at PDX Code Guild, a boot camp, and took courses in programming languages like Python, Ruby and JavaScript.

Steve Deddens, 71, a retired commercial pilot from Austin, Texas, who flew fighter jets during the Vietnam War, said he was a little anxious about embarking on a second career in programming.

He worried about keeping up with his younger classmates at General Assembly, where he took an immersive program two years ago.

“People my age still have an AOL account,” he said.

But Deddens, now a software engineer at a company that provides information technology services to Microsoft, found the transition relatively easy.

“I’ve always been good at solving problems,” he said. “I like taking things apart. I’m an engineer by nature.”

While the income he earns from his second career is certainly nice, he said, “the other side of it is the joy of doing something with your mind and keeping yourself young.”

McKerrow agreed: “I think learning computer skills is great for older people. There is no heavy lifting or physical demands, and exercise of the brain is so necessary to avoid atrophy, Alzheimer’s or dementia.”

One way to get started — or at least see if coding is a good fit — is to attend a meetup. These are organized get-togethers where people sign up online and meet offline to discuss common interests. Codecademy, for instance, holds regular meetups in 300 cities around the world.

I made a commitment to go every month,” said Laurie Alaoui, 59, from Lincoln, Calif., near the Bay Area.

There, she said, she became familiar with the industry lingo and observed coders of all levels. “At the third one, I understood maybe 5 percent of what was said,” she said. “But I took notes, and words I had no idea what they meant, I came home and looked them up. And then the next month I would go to another one.”

“Before long, it got to where I could sit through the talk and understand what they were talking about,” said Alaoui, who became disabled from a car accident in her teens and was looking for something less taxing physically.

In addition to attending meetups, she took lessons in HTML, CSS and JavaScript at Khan Academy, which, she said, “are basically geared toward kids — they spell everything out.” She then enrolled at one of General Assembly’s immersive programs and is now developing Gets You Inc., a website that helps connect people with autism.

“That was the reason I wanted to get into coding,” she said. “I saw that you really can change the world.”