Sergios Aftsidis is joining NOFire AI as a Founding Member of Technical Staff on the Core Infrastructure team. He comes from Hotjar, where he spent three and a half years as a Staff Software Engineer.
Eleven years in, he has done the thing plenty of engineers talk about and few actually go through with: moved into management, ran it properly for two years, then chose to go back to building. He is here for the part of the job that is unambiguously engineering.
Background
He studied Informatics and Telecommunications at the National and Kapodistrian University of Athens. His first job was at GRNET, the Greek national research and technology network, writing internal tooling for its network operations centre and working on software that monitored Juniper devices over SNMP and NETCONF. Backend in Python and Django, with a foot in the infrastructure from the very start.
Then three years at Transifex, which is where the shape of his career gets interesting. He arrived as a senior backend engineer on the core product team, in Python, Django, PostgreSQL and Redis. He picked up Scrum Master duties for a year and a half. Then he became Tech Lead and Engineering Manager, and spent two years on the things that are not code: one-to-ones, career paths, a technical vision for the department, and hiring.
And then he went back to building: a year at Orfium deep in PostgreSQL performance and query optimisation, where he also proposed the CI/CD pipeline on AWS ECS and GitHub Actions, introduced a technical evaluation format for candidates, and ran the backend chapter's mentoring and pair programming. Then Coconut, and then three and a half years at Hotjar, arriving as a senior engineer and leaving as Staff. Stelios Charmpalis, who joined NOFire earlier this month, was at Hotjar for every one of those years too.
The pattern across all of it is someone who keeps becoming responsible for how things get built rather than only what gets built: the database that is too slow, the deployment pipeline nobody owns, the design pattern a team needs but has not written down yet.
What Sergios will own
On the Core Infrastructure team, Sergios owns the foundations: designing systems & infrastructure, building them, then making sure they hold up when real customers lean on them. In practice that spans the migration of the core platform onto firmer ground, and the workflow execution layer that the rest of the product schedules work through.
By his own description it is all of it, from high-level architecture to production readiness. That breadth is the point. Core Infrastructure is where design decisions and operational consequences land on the same person, and he has spent eleven years being that person.
More about Sergios
How did you get into engineering?
I love solving problems, figuring out how systems work and mentoring people. Engineering can be a great vessel to do all of this.
Why NOFire AI?
After a few years in larger enterprises, I felt the need to have more immediate impact on a product & a team. NOFire AI gives me just that. But beyond that, it's not very often you get to contribute such a deep-tech product. The challenges are immense, I find the field extremely interesting and the opportunity to shape the AI solutions landscape couldn't come at a better time.
What will you be working on here?
All sorts of engineering work. From designing systems to be robust & scalable on a high level to implementing them & making sure our solution scales to meet the expectations of our customers. From high level architecture to implementation & production readiness, I'll be doing it all.
Tools you rely on?
Python, Golang, PostgreSQL (and other databases), Kubernetes, a fleet of AI tools.
Outside of work?
I maintain my own blog, where I write about my off-work adventures, the latest of which is my self-hosted kubernetes cluster for experimentation & side projects. When I'm not coding, I'm hanging from cliffs (climbing) & exploring mountains (hiking).
Sergios is based in Greece, writes up his side projects on his own blog, and can most reliably be found partway up something steep.
