Don't look now, but senior snot millennials are the fastest-growing segment of todays workforce. Here's how working longer is changing seniors lives, and why the workforce of the future is being re-engineered with seniors more prominent role in mind.It appears that the days of seniors simply riding off into the retirement sunset may well be fading, with large segments of the senior population now launching encore careers in retirement, and even more not retiring at all. For some, its financially necessary, while others simply don't want to give up the security and satisfaction they get from working, even into those later years like their 60s and 70s.How prevalent is the trend, you wonder? Well, consider this: The U.S. Bureau of Labor Statistics reported in 2016 that 27% of seniors ages 65-74 had full- or part-time jobs and the rate has been climbing for 20 years now! In fact, by 2026, its expected to reach 30%, and as soon as 2030, the number of working seniors 65 and older is expected to surpass the number of workers 18 and under.So by all measures, what were seeing unfold is a demographic and cultural megatrend of epic proportions.The reality is this: Having accumulated considerable knowledge and skills throughout the course of decades in the workforce, seniors value in terms of productivity, team membership, and the ability to mentor and influence younger workers is doing much to re-invigorate employers interest and investment. And because of it, plenty of companies are doing away with ageism and previously held biases that typecast senior workers as being less desirable due to lower tech-savvy, greater health risks, and diminished overall productivity (which, data suggests, is unproven if not altogether false).As the future unfolds, here are no less than 7 employment options and avenues that are more open than ever for seniors, and how those who follow something other than the traditional retirement route might go about pursuing additional career interests as their working years kick into overtime.ConsultingEmployers are coming to embrace the concept that its often bad business to simply let senior workers, who are presumably experienced and long-tenured team members, just one day walk out the door. And that paves the way for retiring seniors to stay on as consultants, working on a contract or project basis for their employer or (gasp) the competition if the grass is indeed greener over there.Phased RetirementSomething of a new concept, phased retirement is when a senior worker, in partnership with their employer, begins to dial back time and/or workload to create a longer and more controlled transition to full-on retirement. It allows contributions to continue, which benefits the company, while also allowing seniors to dip a proverbial toe into the retirement pond and see what life is like without the everyday 9-to-5.Encore CareerSome seniors who struggle to occupy their days in retirement have become entrepreneurs and started some fascinating second acts of their own. Whether opening retail shops or other small businesses, brewing craft beer or spirits, or doing trades like wood or metalworking, the choices are unique as each individual senior and limited only by the depth of their skills and their ability to kick in or raise the necessary startup cash.Sports/Interest-Based EmploymentRetirement, for many, is a long-awaited opportunity to devote more time to favorite activities and pursuing longtime interests, whether its golf or tennis, music or the arts, and so on. No surprise, then, that pursuing interest-based employment is a fine way to get more immersed in those arenas or others. Part-time jobs like these aren't hard to come by, and seniors will likely find fun and fulfillment in doing something they love, while the modest, hourly compensation provides a little, extra income on the side.TeachingVarious programs exist nationwide that aim to create teaching and mentorship opportunities between seniors and the younger generation. AARP and other service-minded organizations, as well as institutions for higher learning, are all actively looking for retirees to share knowledge and expertise on everything from machine tools and mathematics to business and foreign languages and beyond.Travel IndustryGetting paid to travel may sound too good to be true, but it turns out seniors who know where to look can enjoy their dream of exploring the US and beyond in retirement and can even earn money while doing it! Cruise lines, tour and excursion companies, and seasonally driven resort communities in popular beach and ski locales can provide interesting employment options, all while offering wonderful opportunities to head out in search of excitement and worldly adventure.Healthcare & Medical ResearchPlenty of seniors volunteer their time at local hospitals, assisting patients and visitors. But few know that there is a need in the medical trial and research space as well, where seniors are needed to help analyze and track data, as well as assist with bookkeeping and administration. Those who wish to get involved might try making contact with the research departments at area hospitals and universities, where work is being done today to uncover the medicines and treatments of tomorrow.