Hi. I'm Charles. I'm Simwood's CTO, which means I'm accountable for the technology across the group: the network, the platforms that run on it, and the teams that build both.
Some of you have known me for a long time. There is a post from 2018 where I answered much the same questions much like these as the founder of a company called Sipcentric. It's still online, which is either brave or careless! Reading it back was a useful exercise. Most of what I said then, I would still say now. The scale is what changed.
The long way round
My route into telecoms was not direct. Before any of this I had launched an online trading company and an IT consultancy, built a small property portfolio, and opened a couple of bars. I have always been more interested in businesses and people than in any single technology, but IT and telecoms was where my expertise sat, and internet-based communications was where the interesting problems were.
Sipcentric was formed in late 2010, and we rebranded to Nimvelo in 2015. Over nine years we built a hosted platform, and the team to run it, without any significant outside investment. That constraint shaped everything. When there is no funding round to hide behind, you architect carefully, because you are the one who will be supporting it at 2am.
I also said in 2018 that we were working on something new, that I could not say much about it, and that its purpose was to help teams have more productive conversations. Hold that thought.
October 2019
Simwood acquired Sipcentric in October 2019. Simon was characteristically direct about why: he reckoned we had built the best-architected hosted platform in the market and that almost nobody had noticed.
Shortly afterwards I stepped up to Group CTO, a role Simwood had not had before. Going from running your own company to running technology inside a larger one is a genuine change, and it takes some adjusting to. What made it work was that this was not the usual sort of acquisition. Several of the Sipcentric team took senior positions in the combined business rather than being absorbed and quietly forgotten. David Maitland, who wrote in this series back in March, was Sipcentric's second employee at nineteen and is still here running infrastructure and systems. That says more about how the two companies fitted together than any press release did.
What I gained was scale, and colleagues who had been operating networks at serious scale since 1996. What Simwood gained, I hope, was a platform team used to shipping.
What the job actually is
I am responsible for the ongoing reliability and interoperability of every network across the group, and for the products we build on top of them. In practice the work splits three ways: keeping what exists running properly, building what comes next, and making sure the people doing both have what they need to get on with it.
The middle one gets the blog posts. The first one is where the credibility comes from.
A lot of that foundation is decidedly unglamorous. Database clusters that need to fail over cleanly rather than theoretically. Identity and single sign-on, migrated without locking anyone out. An intermittent lock-up that only ever appears in production, under real traffic, at the least convenient hour. None of it makes a good headline. All of it is the reason customers can put us in the call path and not think about us again.
Some of it has been running longer than the products it now supports. Kamailio has been in Simwood's stack since 2005, and it is still there, doing the same job in a completely different architecture. I told that story on stage at Kamailio World in May: twenty years of change with one constant in the middle of it. Contributing back to the open-source projects we depend on matters to me. We would not have a business without them.
Back to that thought
In 2018 I was talking about helping small teams have better conversations, from inside a PBX. Today the AI engineering team and I are building Conversation Intelligence, which does something similar from an entirely different place: the carrier layer.
Media is tapped passively at the network layer and mirrored into an AI pipeline. Nothing touches the call, nothing adds latency, and nothing routes through a third party, because we are the carrier and it is our network. Operators watch the transcript as it unfolds and emit typed signals — a fraud score, a detected intent, a compliance flag. Those signals fire webhooks into your platform mid-call, or whisper guidance to the handler while they are still talking. Every conversation becomes a vCon, an open IETF-standard record, held in your storage rather than ours. We genuinely do not want your data.
The pitch is simple: act while the call is still happening, instead of finding out next quarter. Fraud caught before the transfer is authorised. A missed disclosure prompted before the call ends. If you would rather read endpoints than prose, it is all in the developer docs.
Different scale, same idea I had eight years ago. It only works now because we own the whole stack, which is precisely what the 2019 deal put together.
How I try to work
My answer in 2018 was that I liked being one of the team and would never expect anyone to do something I would not do myself. That has not changed, and it is easier to live by here than it was, because Simwood already worked that way.
What I would add now is a preference for candour. I want to know the difference between what we have shipped and what we intend to ship, in plain terms, early. Optimism about a roadmap is fine. Confusing it with the current state of production is not, and it is the fastest way I know to lose a customer's trust. The same goes upwards: if I am wrong, I would rather be told in the room than discover it in an incident review.
The flip side is ownership. Nobody here waits to be told to fix something they can see is broken, and that is recognised rather than merely expected. You will find the same theme running through most of the posts in this series.
Away from the network
Home is a few rural acres, which supplies a reliable stream of problems that cannot be solved with more compute. There is a garage block mid-conversion and a planning process attached to it, so I have developed a new appreciation for systems where the specification is deliberately ambiguous. The rest of my time belongs to my family, who are unmoved by SIP.
Still here
Eight years on from that first post, and seven from the acquisition, I am still doing a version of the same job: building communications infrastructure that other people can rely on without having to understand it. The difference is the size of the network underneath it, and the calibre of the people I get to argue with about how it should work.
That is why I am still here. It is a rare combination, and it has not gone stale yet.