The closest thing I could suggest is looking at the family of cephalopod molluscs, which includes octopi and squids. At some point in their evolutionary history they shed their shells and became much more mobile and intelligent as a result.
Now one of the limitations of their body plan is there are no rigid attachment points for their muscles, which allows them to do things like squeeze in and out of bottles (for octopi) and assume streamlined shapes for high speed "jet" flight (squid). These are very advantageous in the oceanic environment where they live, but if a similar creature lived in the intertidal zone and became amphibious as a result, this might become a disadvantage. Such a creature might evolve a partial covering over the vulnerable body but leave the limbs free, which could become a form of exoskeleton if the creature evolves further to use the hard "shell" as an attachment point for some or all of the musculature of the limbs.
This would allow the creature to assume a more "upright" posture, elevating its eyes and sense organs to give it a greater field of view, a tremendous advantage on land. As well, over the ages some of the limbs might evolve into thick, muscular "legs" while other limbs would become smaller and more flexible to manipulate objects (for example, pulling aside rocks to get at tasty prey animals).
We now have some of the basic elements for evolving intelligence, in an environment where increasing intelligence would be rewarded. If the ancestral creature was "social", living in pods or schools, then there would be another big driver for intelligence: the need and ability to communicate among themselves. To make this work towards becoming technological creatures, they would start using their cooperative powers to extend their swamps by digging channels, levees and ponds to manipulate the flow of water to their advantage, developing more complex tools, social structures and understanding of natural forces to build elaborate swamps. The last thing would be for some to move to land more permanently and discover fire.
From their ancestry (and if they retain some or all of their amphibious characteristics), they might actually be better with 3D environments like the air and space, and if they retain very flexible manipulator arms and tendrils, they will have less of an issue working on small items or items crammed into small spaces where human hands would not fit. OTOH, our bones and musculature would allow us to generate more force, so an alien based on the cephalopod mollusc body plan would have a hard time using human technology like screwdrivers, hammers or wrenches. Alien artefacts might be sewn or glued together, for example, and forging metal objects might be a very late development in their technology (their metal technology might be soft castings and sintered metals). This would make developing internal combustion engines, jets and rockets difficult, slowing down their ability to get to space. Their spacecraft would also have am performance issue if they are still amphibious, since the craft would need to carry a lot of water aloft (which is heavy), meaning a Saturn V sized rocket might be needed to get a single "astronaut" into space.