Data, custom builds and AI, in and around your HubSpot
Our engineers build what your HubSpot cannot do alone, and connect it to your portal.
Book a call with KlemenKlemen Hrovat, our co-founder, takes the first call. It is free.
- Black mark: your HubSpot portal
- Gray dot: a record in it
- Gold figure: what we build for you
Your HubSpot
We fill the HubSpot properties your market sells on, link each contact to the right company, flag who moved and stop bad data where it comes in.
Zebra BI: more than 80% of manual data work removed
When an existing tool does the job, we use it. When none does, we build the app, integration or migration, inside HubSpot or next to it.
ATLANT 3D: a custom build that finds research institutions with active grants
For each task, we decide what code does, what AI does and what your team approves. Agents act alone where a mistake is cheap, and wait for your approval where it is costly.
More than a million agent runs on clients' HubSpot data since March 2025
since 2022 AI agents in production on client HubSpot data
100+ HubSpot portals where our apps and agents have run
ISO/IEC 27001 Both our companies, certified by InterCert
SOC 2 Type 1 report from a CPA firm,
Type 2 in progress
Data your team can act on
We work on four parts of your HubSpot data. What each record says: company size, job title, and properties only your market uses, such as a researcher's field of research. How records connect: each contact linked to the right company, also from a personal email, and one record per person at each company. How records change: we flag buyers who move to a new company. Where bad data comes from: we screen form entries and fix the workflows that make bad records. As one project, or every day.
Custom builds for what HubSpot doesn't do
Some jobs need something HubSpot does not do on its own. For Zebra BI, we built an agent that finds the size of companies no data source covers, so every account can be scored and prioritized. For ATLANT 3D's sales to universities, we built a way to see which research institutions have active grants.
When an existing tool does the job, we use it instead. We build only what does not exist yet, because every extra tool is one more thing your team must learn and look after.
AI in the loop, where a step needs judgment
For each task, we decide what plain code does, what AI does and what your team approves. Code takes every step that has one right answer. AI takes the steps that need judgment, such as finding the company behind a personal email, and it may answer "not found" instead of guessing.
Some agents run a whole process on their own, inside rules that your team sets. Others work with one of your people: the agent prepares the work, and the person decides. How much an agent does alone depends on what a wrong answer costs. Where a mistake is costly, your team approves first.
What changed for four clients
Every number here is from the client's published case study.
From 90% to 30%
RevOps time on data management
ATLANT 3D Deep tech
We cleaned and enriched their data, and set up workflows that stop bad data at the source.
From under 15% to 30%
Email open rate, in one year
BMG LABTECH Life science
We built data pipelines for them. One flags contacts who have changed jobs, which protects their sender reputation.
More than 80%
Manual data work removed
Zebra BI Business intelligence software
We built their data foundation and job-change monitoring, which found a quarter of their past buyers at new companies.
25,000
Company records cleaned
Ecom Diversify Owner-led marketplace
We rescued a HubSpot they were weeks from canceling, and turned off a broken workflow that had made duplicate companies for years.
Engineers who understand B2B sales
We have run sales businesses ourselves for more than a decade, so you don't have to explain how B2B sales works or babysit us.
Nejc Škoberne CEO
PhD in computer science. Leads AIRops, a HubSpot User Group on AI in RevOps.
Klemen Hrovat CRO
HubSpot Community Champion. Leads the commercial side, and takes your first call.
Matevž Poljanc CTO
Studied computer science at the University of Cambridge. Leads our technical work.
Certified and independently audited
Our work needs access to your CRM, so both our companies are certified to ISO/IEC 27001:2022, and a CPA firm has examined Sellestial, Inc. for a SOC 2 Type 1 report. Our SOC 2 Type 2 report is in progress.
A data processing agreement You get a DPA with us
Subprocessor list under NDA The companies that process data for us
A SOC 2 Type 1 report As of October 1, 2026, under NDA in our Trust Vault
Start with a free call
We do the engineering part of HubSpot work: data, custom builds and AI. You may need only one of the three. In the call, you tell Klemen what you need from your HubSpot, and he tells you which part we would take on. If a partner fits a part better, we tell you that too.