AI tutoring startup
Replaced message-count entitlements with cost-based usage metering and built the AI tutor's memory pipeline, on a platform used by millions of secondary-school students.
Hi there, I'm
Senior Software Engineer
AI & LLM Systems
I build software products end to end, and lately the LLM systems inside them.
Remote since 2011 Β· Slovenia Β· English and German
Open to a long-term role, employed or on a B2B contract. What I'm looking for β
I started coding back in 2004 with simple HTML sites, and somehow ended up building systems that handle millions of users. Along the way, I've discovered that the best software isn't just about clever code - it's about solving real problems for real people. What teams tell me they value is that I take ownership, communicate honestly about tradeoffs, and stay with a system long enough to be accountable for it.
These days, I work mostly with TypeScript, React, Node.js, PostgreSQL, Python, Docker and Kubernetes, across product code, data pipelines and infrastructure. I use modern AI-assisted development workflows where they improve delivery without compromising engineering quality, and I've also built LLM-backed product features - usage metering, memory, classification pipelines, alerting and search - as part of real systems.
From my own projects like Guestavo, Metis and MoaiTime, and WeWentCarRacing (because I love motorsports), to work with Edukey and TES Global, through agencies for Philips, RWE, Innogy, Red Bull, Danone, Les Mills and Radenska, and a smart-city platform - I enjoy building things!
I've been remote since the start of my career in 2011, long before it was normal. Fifteen years of clients and teams in the UK, Germany, Austria, Switzerland and the US, across time zones and mostly in writing, means a distributed team is the setup I know best.
I started producing and DJing electronic music as a teenager and came back to it recently. Some productions are on music.bobalazek.com, and I wrote about the journey and my library.
My 3D printers turn ideas from my other hobbies into real parts. The biggest build so far is a DIY formula-style sim racing steering wheel, which I wrote up prototypes and all.
I follow racing closely enough to have built WeWentCarRacing, a calendar across 20+ series. I race on the sim too, which led to WeWentSimRacing and a post about my setup.
I wrote the physics helper in the Babylon.js 3D engine, and it still ships. I also publish my own projects, like MoaiTime, OpenVoice Flow and my agent skills.
π©πͺ Γbrigens, ja, ich spreche natΓΌrlich auch Deutsch! Diese Seite gibt es auch auf Deutsch.
The teams I've worked in and what I built for them.
Replaced message-count entitlements with cost-based usage metering and built the AI tutor's memory pipeline, on a platform used by millions of secondary-school students.
Took over an agency-built investment-intelligence platform and worked across its web and mobile apps, AI layer and infrastructure until the company wound down in March 2026.
Designed the backend of a smart-city programme: 20+ microservices on Kubernetes across five city domains, built in parallel by several vendor teams.
Joined ClassCharts as the first developer alongside the CTO and stayed eight years as it grew past ten million pupils, parents and teachers, through its acquisition by TES Global.
My own company. Around 70 client projects since 2012, many of them through agencies for brands like Philips, RWE and Red Bull.
Visit Corco Labs : Corco Labs β " I worked with Borut for 8 years, he was our longest serving developer and he was an excellent person to work with. Borut always feels & displays a high level of responsibility to the project and the team and brought immense value to what we were trying to achieve, he understood our vision & grew with our codebase to become a hugely valued developer who you could rely on & would always deliver. Time keeping, attention to detail & working with others were never a problem. Borut worked on each of our products, working with different team members, platforms and codebase & responsibilities. I have zero hesitation in recommending Borut as he is an intelligent & hard working individual with a good sense of humour and liked by the rest of the team - he was a huge asset! " " Borut delivered immediate value after joining our team. He brought clarity to complex problems, unlocked efficiency, and significantly increased throughput. He quickly identified mission-critical technical debt and resolved it on schedule. Borut communicates clearly with both technical and non-technical stakeholders and consistently connects technical concepts to practical business goals. His experience enables him to leverage AI to accelerate delivery without compromising quality. We were fortunate to have him on board and would gladly collaborate with him again or recommend him for any project. " If your team is putting language models into a product, these are the parts I have already built and run in production: what each call costs, what the model remembers, what it retrieves and what an agent is allowed to change.
Each request is priced by the tokens it uses, checked before the model call and charged only once the call succeeds, across every plan tier.
How it works : Usage metering by token cost βLasting facts are extracted from conversations in the background, then merged and pruned every night, with the load spread so the database stays flat.
How it works : Long-term memory for an AI tutor βAround 100,000 articles a day are embedded into Qdrant, searchable by meaning and available to an LLM agent as tools before it makes a call.
How it works : Retrieval over news at scale βA cheap model takes the first cut and a stronger one runs only where the call is hard, behind one registry of providers that can be swapped.
How it works : Classification with a cheap first pass βAn operator runs a venue from an AI client, while every change an agent makes is logged with its before and after state and can be undone.
How it works : An MCP server with guardrails βI work with coding agents every day, with every change verified and reviewed by a second model and by me. The workflow is public as agent skills.
How it works : Building with coding agents βNotes on what I build and how I work, here and on Substack.
A few engineering decisions from my eight years on ClassCharts.
7 min read
A tour of my coding agent skills and how they fit together.
10 min read
An update on Metis and its financial data tools.
8 min read
My five attempts at building a personal assistant that remembers.
9 min read
Senior or AI engineer roles, or a technical lead seat where I still write code. EU employment or a long-term B2B contract.
I also take on freelance projects. Send me what you need built or fixed, and your timeline.
Discuss a project βMy client work has run as B2B contracts through Corco Labs, my own company, because most of my clients were abroad and could not employ me in Slovenia.
Borut Balazek
Senior Software Engineer, AI & LLM Systems