About

Built by a Marketer Who Speaks Data.

Diligent Digital was founded on a simple observation: most brands separate their paid media teams from their data teams, and pay the price in blind spots, misaligned incentives, and wasted spend.

I’m Kiril Terziev — a performance marketer and data engineer who has spent a decade building the bridge between those two worlds. I work directly with marketing leaders and founders who want a single, accountable partner across ads, analytics, and infrastructure.

I’m a 15+ Years Optimising Google Ads and Meta Certified Marketing Developer, with additional certifications in data science and analytics from IBM and Google. I work in English, French, and Bulgarian, with clients across Western Europe and beyond.

The name says it. Diligent Digital isn’t about doing more — it’s about doing it right.

Kiril Terziev
Founder & Principal Consultant
15+ Years Optimising Google AdsGoogle
Meta Certified Marketing DeveloperMeta
Data Science SpecializationIBM
Google Data AnalyticsGoogle
Statistics and RedX / Verified
Data Analysis with PythonIBM
📍 Sofia, Bulgaria — Working globally
Philosophy

How We Think About Growth.

Principle 01

Margin Over Revenue

Revenue ROAS flatters. Margin ROAS tells the truth. We optimise for what actually ends up in your pocket — not what looks good in a dashboard screenshot.

Principle 02

Data First, Always

Every recommendation we make is traceable to data. We don’t rely on gut instinct or platform defaults. If we can’t measure it, we build the infrastructure to measure it first.

Principle 03

Systems, Not Campaigns

A great campaign inside a broken measurement system is a waste of money. We build the full stack — attribution, tracking, bidding logic, and creative — so everything works together.

We Work Where You Grow.

With native fluency in French and Bulgarian, and full professional proficiency in English, we work comfortably with clients and campaigns across Western Europe, the UK, and beyond.

🇬🇧 English 🇫🇷 French 🇧🇬 Bulgarian

Ready to Work With Someone Who Gives a Damn?

No retainer minimums on the first call. Just a straight conversation about your brand and whether we’re a good fit for each other.

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