Kathmandu looked as though somebody had installed the city’s electrical system by throwing cables into the air and seeing where they landed. Cars, motorbikes and pedestrians competed for the same pieces of road. Potholes were a participant in the traffic. Not long after leaving the airport, our car ended up behind a tiny hatchback with MANCHESTER CITY TAXI written across the back.

At the time I was working on an early payments product inside ConsenSys. I wanted to know what happened when the things we take for granted are unreliable: connectivity, banks, cash machines. Nepal seemed like a useful place to find out, and the fact that I also got to climb some very big mountains was not incidental.

We flew from Kathmandu to Lukla to begin the approach into the Everest region. Our guide was Netra. On the flight into Lukla he pointed out his community below us and told me he was the leader of its local council. That he was a medic in climbing parties before anything else. That he had climbed around the world. Transported bodies. Netra talked enough for several people. The rest of our team became easier to know more slowly.

Nikesh, one of our porters, lived just above Lukla, where we met his family. We tried carrying the porters' bags for a while and established why they were carrying the bags rather than us. The porters routinely pushed ahead on the trail and would be sitting around recovering by the time we arrived anywhere.

While walking through the forests and rope bridges between Lukla and Namche Bazaar, I met other guides. One told me that clients were sometimes made ill deliberately because a helicopter evacuation created opportunities for people to make money. Netra had separately told us not to eat meat after Lukla, and warned that other guides might encourage it. I was vegetarian, so this was unusually easy advice to follow. At the time I had no way of knowing how seriously to take the claim. It later turned out to be very plausible.

We were there in December, when much of the local economy was beginning to shut down. Tea houses had closed for the season and people were leaving the mountains for Kathmandu. Places that would have been crowded a few months earlier were almost empty. In Namche Bazaar, another guide told me he had lost a client to rockfall on Yellow Tower earlier that year. As he spoke, children ran between two school buildings to brush their teeth. In one tea house, a yak peered at us through a doorway. Usually, the tea house was run by what felt like a matriarch. Photos of their children and grandchildren covered the walls: the sons stood on the summits of mountains around the world, their daughters at Universities in Europe and the US.

The forest gave way to barren scree as we ascended further. Ama Dablam, which started as a sight on the horizon now loomed over our approach. We passed a memorial to climbers who had died in the mountains, and prayer flags were everywhere around the base camps. Toilets froze. There was effectively no hot water. Helicopters buzzed in the valleys below us. I woke up to find the water in my bottles frozen solid. Keeping my water water rather than ice became an ongoing concern.

Everest Base Camp was deserted apart from a single rock with the name scrawled on it. On Kala Patthar, a dog that looked like a spaniel followed us all the way to the summit to watch the sunrise hit Everest. We watched a huge avalanche come down the side of Nuptse. The rumbling made it feel enormous, but the mountain made it look small.

The internet, however, persisted. Tea houses maintained connectivity because mountaineers wanted to post on Instagram and would pay for it, and that access extended to the people living and working around them. So, my hypothesis was getting awkward: the toilet had frozen and somebody was burning dung so we could drink water. But the internet worked. In Chukhung, there was a snooker club for locals, guides and porters. Nikesh told me he wasn't Sherpa and wasn't welcome inside. There was a coffee shop that accepted Apple Pay for the mountaineers.

On the approach from Chukhung to Imja Tse base camp, one of the climbers kept slowing us down to take photographs. By then we were well above 5,000 metres, and I was tired. The mountains were beautiful and I still wanted them to put the camera away. Nikesh was with us because Netra had been encouraging him to come farther than he normally would. First Everest Base Camp, then Kala Patthar. He asked for photos each time we reached somewhere new. And every time, this made me happy.

At base camp, immediately before our summit attempt, I got flyer's tooth. I couldn’t sleep. At some point during the night, after exhausting the more conventional options available inside a tent, I decided the solution might be to clench my teeth hard enough to crack the offending tooth open. It was -40°C and, incidentally, -40°F. Every time I had to leave the tent to piss, I felt respite and forgot about my tooth. And after two evenings acclimatising, we started climbing in complete darkness. The only other party at base camp, a group of Oracle consultants training for Everest, had left the day before.

It is difficult to maintain a particularly sophisticated theory of infrastructure while climbing in the middle of the night after considering ways to perform dentistry on yourself. But one thing was becoming obvious: remote did not mean that everything failed equally. Medical care was very far away. Hot water had disappeared. Drinking water required work. But Netra could still check his phone.

We crossed the glacier capping all but the summit ridge. The headwall to the summit cast a shadow so cold that I wanted to turn back there and then. I was exhausted. Toothache. Netra called me a baby. I climbed the headwall to the knife-edge ridge, then summitted my first 6,000m peak. Lhotse towered more than 2,000 metres above us, and Chukhung appeared to be 1,500m directly below us. Then Netra lit a cigarette, whipped out his phone, and called base. My hypothesis was dead. No workshop was required. Pack it up boys, time to go home.

On New Year’s Day we reached Namche Bazaar and had hot water for the first time in weeks. We got drunk. I vomited in the bathroom. Netra asked about it the next morning and I denied it. He knew and he knew I knew he knew.

At the end of the expedition I needed to tip the guides, porters and cooks who had supported us. I had money, working cards and access to PayPal. What I did not have was enough cash. But one of the other climbers did. I asked if they would cover my tip in physical cash if I transferred the equivalent amount over PayPal first. They agreed, but written down like that it sounds much more straightforward than it felt.

We had been travelling together for weeks and sharing tents. We knew what we smelled like after weeks of no showering. There were only three climbers in our group, so refusing also meant continuing to share rooms with the person who had just announced that, despite having perfectly functional digital money, he could not pay the customary tip to the people who had spent a month helping keep him alive.

I sent the PayPal transfer, they gave me some of their cash, and I could tip the team. Nothing had obviously failed. My money existed. The cards worked. PayPal worked. The internet worked. The team received tips. I had successfully made my problem somebody else’s.

I didn't return from Nepal with a roadmap or a validated idea. I came back 7 kg lighter, with spectacular sunburn on the bridge of my nose, an emergency root canal appointment, and the memory of my tentmate becoming a very temporary payment institution.