Chief Technology Officer — SkyFi

JulianSirakov

Pushing limits driven by curiosity.

I build the engineering organisations behind complex systems people depend on — today, the Earth intelligence platform at SkyFi.

View experience LinkedIn ↗ 20+ yrs in technology leadership
01

About

Zug, Switzerland

Engineering leader with a strong bias toward technology, an open mind, and genuine curiosity about how things work.

As CTO at SkyFi I lead the engineering organisation building an Earth intelligence platform — making satellite imagery and geospatial analytics accessible to people who have never touched a GIS tool. That spans a commercial marketplace, AI products, government and defence programmes, and the infrastructure underneath all of it.

Twenty-plus years in, I still start from the customer’s problem rather than the tooling. The right technology is the one that answers the question they actually have, not the one the team would most enjoy building with. That is why the list below keeps growing, most recently with AI.

Layers
UI · Backend · Infrastructure · AI & ML
Domains
Payments · Finance · Tax & compliance · SaaS · Developer platforms · Virtualisation · Earth observation
Tech
Java · Python · Go · JavaScript · Kubernetes · and a long tail of things that seemed important at the time
02

How I lead

Six principles

I wrote these as SkyFi’s engineering principles. They decide what we build as much as how we build it, and none of them are new — they are how I have worked for most of my career. Putting them in writing changed one thing: it made them something the team can hold me to.

01

Ownership

You build it, you run it.

Responsibility does not end at the merge, or at the release note. It ends when the thing is in someone’s hands and solving the problem it was built for. That means caring about the shape of the feature as much as the reliability of the service behind it — and fixing what you find broken without waiting for permission.

02

Proactiveness

Don’t wait to be told.

The best teams see the problem before it is filed: the customer workflow about to break, the market moving, the root cause that will cost ten times more next quarter. Bring the idea as well as the fix. When in doubt, do something — stagnation usually costs more than a wrong decision you can correct.

03

Agility

Respond to change over following a plan.

Ship small, ship often, and let real usage settle arguments a roadmap document never will. Don’t fall in love with your first solution: the plan is a hypothesis and the people using the product are the ones who get to falsify it. Maximising the work not done is a genuine skill, and an underrated one.

04

Courage

Speak truth to power.

Someone has to say the roadmap is wrong, the estimate is fiction, or the feature nobody uses should be deleted. Challenging a plan is as valuable as challenging an architecture, and usually less popular. It only happens when failure is survivable, which makes psychological safety a precondition rather than a perk.

05

Speed

Speed is a feature.

Speed is how fast you learn, and it is also something customers feel directly. Take the friction out of the path from idea to production, invest in the pipeline until you trust it, and remember most decisions are reversible — a good decision today beats a perfect one next quarter.

06

Embracing AI

Augment your intelligence.

Two questions, always: how does AI make this problem smaller for the team, and how does it make the product genuinely better for the person using it? Both matter, and they are not the same question. Stay current, experiment in the open, and stay honest about what the tools cannot yet do.

03

Experience

2003 — present
  1. Sciant
  2. VMware
  3. Uber
  4. Paysafe
  5. Docker
  6. Mirantis
  7. HireHeroes
  8. HALO
  9. SkyFi
Twenty-three years, nine companies — three of them changed hands around me
Jul 2022 — present · 4 yrs 2 mos
Synthetic aperture radar capture of the Gatún locks on the Panama Canal
Panama Canal · Umbra SAR©2023 Umbra Lab · via SkyFi

Earth observation marketplace & platform — SkyFi

SkyFi is democratising access to satellite imagery. I lead the engineering organisation — around 45 people across five teams covering the commercial platform, AI, government and defence programmes, and the infrastructure underneath all of it.

  • Platform aggregates 300+ imagery sources across 40+ providers, with delivery in under 24 hours.
  • Selected by U.S. Special Operations Command for Phase I development of a Sovereign Intelligence Platform prototype and an integrated ATAK plugin.
  • One of five companies advanced into NATO DIANA’s Mission Track from a 2026 cohort of 150.
  • Grew the organisation through Series A, from early product to a platform business serving commercial, government and defence customers.
Since I joined
The app went into beta two months later, with around 300 invited users. It is past 100,000 today.
Latest
A $12.7M Series A in January 2026, co-led by Buoyant Ventures and IronGate — oversubscribed from an $8M target.
  • Chief Technology Officer

    Jul 2025 — present · Remote

    Own technology strategy and the engineering organisation end to end — commercial platform, AI products, government programmes and infrastructure.

  • Head of Engineering

    Sep 2024 — Jul 2025

    Led the engineering team building the next generation Earth observation marketplace and platform for data and analytics.

  • Senior Engineering Manager

    Jul 2022 — Sep 2024 · Bulgaria

    Built out the engineering team and delivery practice as SkyFi scaled from early product to a platform business.

Oct 2020 — Jun 2022 · 1 yr 9 mos
$19MSeries AMarch 2021

Sr. Engineering Manager — HALO Diagnostics

Sofia, Bulgaria

Built innovative software for medical diagnostics — advancing imaging-based diagnosis and personalised treatment to improve human health and wellbeing.

While I was there
A $19M Series A in March 2021, with Anne Wojcicki and Fred Moll among the angels. The company put Subtle Medical’s deep-learning reconstruction into its imaging centres — shorter MRI scans and lower PET dose at the same image quality.
Since I left
Now HALO Precision Diagnostics, running fifteen locations across four states.
HireHeroes.bg Sep 2019 — Jan 2021 · 1 yr 5 mos

HireHero — helping engineers advance — Contract

Sofia, Bulgaria

Career consulting and advisory for engineers navigating the step from individual contributor into senior and leadership roles.

Dec 2019 — Jul 2020 · 8 mos

Director of Engineering — Mirantis

Through the acquisition of Docker Enterprise · Sofia

Led the team through the integration into Mirantis following the Docker Enterprise acquisition — holding delivery and morale steady across an ownership change.

While I was there
Mirantis had just bought Docker Enterprise — a third of the Fortune 100 ran on it — and my team arrived with the deal.
Since I left
Docker Enterprise became Mirantis Kubernetes Engine. IREN acquired Mirantis in August 2026.
Jun 2019 — Dec 2019 · 7 mos
8BPulls a monthNovember 2019

Director of Engineering — Docker, Inc

Bulgaria

Responsible for building a team from scratch in Sofia while leading Docker Hub (~12 engineers) and Docker DTR (6 engineers) remotely.

The Sofia site onboarded UX designers, QA automation, infrastructure and security engineers. We hired ten engineers and shipped features across Docker Hub and DTR, including 2FA for Docker Hub.

While I was there
Seven months that ended with Docker splitting in two: the Enterprise business sold to Mirantis, $35M raised the same day, and a third CEO inside one year. Docker Hub was serving eight billion pulls a month.
Shipped
Two-factor authentication on Docker Hub, October 2019.
Since I left
Twenty million developers and twenty billion pulls a month.
Jul 2017 — May 2019 · 1 yr 11 mos
£2.96BNTaken privateDecember 2017

Senior Manager, Platform Services & Infrastructure — Paysafe

Sofia, Bulgaria

Led four teams (one remote) across shared services, platform and IaaS — responsible for delivering high-quality PaaS and SDLC tooling to product teams, including the containerisation effort that moved services onto Docker images and Kubernetes.

Organised the company’s first internal hackathon: 50 engineers, 12 teams, roughly 30% of the IT workforce. It produced two shipped features and two prototypes that went into the backlog.

While I was there
Blackstone and CVC took Paysafe private for £2.96bn six months after I joined; it left the London Stock Exchange that December.
Since I left
Back on the NYSE since 2021, with $167bn of annualised transaction volume in 2025.
Apr 2014 — Mar 2017 · 3 yrs
0→50EngineersIn three years

R&D Site Lead — Uber

Sofia, Bulgaria

Grew the site from zero to 50 engineers, onboarding two managers and twenty-plus engineers, with full ownership of the domains the site held.

Led work end to end — requirements through rollout and support — across partner banking details management, KYC identity verification, automated receipts, invoicing on behalf of partners, and real-time tax calculation and reporting.

While I was there
I joined the month Uber announced its hundredth city. Eight months later it was 250+ cities in 50 countries.
On the record
Uber’s engineering blog still describes the Sofia site as one of its first distributed engineering offices, built around tax and compliance across 80+ countries.
Since I left
Public on the NYSE since 2019 — 3.9 billion trips in the second quarter of 2026 alone.
Oct 2007 — Apr 2014 · 6 yrs 7 mos
40+EngineersOn one programme

Sr. Manager R&D — VMware

Delivered user interfaces across the vSphere platform, managing teams of 10–20 engineers directly and 40+ indirectly on a single programme.

Led the multi-year, multi-site effort that moved the vSphere management interface from a C# desktop application to a Java/Flex web application, delivered in 2013, and presented the vSphere Web Client at VMworld US 2012.

While I was there
I arrived weeks after the IPO — the largest US technology listing since Google. VMware closed 2013 at $5.2bn revenue and around 14,300 people.
Since I left
Broadcom acquired VMware in November 2023 for roughly $61bn.
  • Sr. Manager R&D

    Apr 2012 — Apr 2014
  • R&D Manager

    Jan 2009 — May 2012
  • Senior MTS

    Oct 2007 — Dec 2008
Mar 2003 — Sep 2007 · 4 yrs 7 mos

Software Engineer → Senior Engineer / Lead — Sciant AG

Design specifications, delivery, team leadership, task management and mentorship of junior engineers across a range of engineering projects.

How it ended
VMware acquired Sciant in October 2007. That is how the next seven years happened.

Education

Sofia University

MSc — Computer Software Engineering

Sofia University · 2005 – 2011

BSc — Computer Science

Sofia University · 2000 – 2004
04

Selected work

Organisations & programmes
SkyFi · 2022–present

Engineering organisation

Grew the engineering organisation to ~45 engineers across five teams — commercial platform, AI, government and defence, and infrastructure — taking it from early-stage product work through the company’s Series A and into programme work with NATO and U.S. defence customers.

SkyFi · 2026

Sovereign Intelligence Platform

Phase I prototype for U.S. Special Operations Command: mission-critical geospatial imagery delivered to the tactical edge, with an integrated Android Tactical Assault Kit plugin.

Uber · 2014–2017

Sofia engineering site

Built from zero to 50 engineers and two managers, holding full ownership of partner banking and payments, KYC identity verification, invoicing on behalf of partners, and real-time tax calculation.

Docker · 2019

Sofia engineering site

Stood up a second site from scratch — ten engineers spanning UX, QA automation, infrastructure and security — while leading Docker Hub and DTR remotely. Shipped 2FA for Docker Hub.

VMware · 2007–2014

vSphere Web Client

The multi-year, multi-site migration of VMware’s management interface from a C# desktop application to a Java/Flex web client. Delivered 2013; presented at VMworld US 2012.

Paysafe · 2017–2019

Platform & containerisation

Four teams across shared services, platform and IaaS, delivering PaaS and SDLC tooling and moving services onto Docker images and Kubernetes.

05

Recognition & speaking

Selected
  • 2026

    NATO DIANA — Mission Track

    SkyFi among five companies advanced from a cohort of 150, moving toward operational adoption across the Alliance.

  • 2026

    U.S. Special Operations Command

    Selected for Phase I development of a Sovereign Intelligence Platform prototype and ATAK plugin.

  • 2026

    The Bridge VI

    Invited among 250 Bulgarian founders, investors and operators from around the world.

  • 2012

    VMworld US — San Francisco

    Presented the vSphere Web Client, VMware’s browser-based management interface.

Let’s talk.

I’m happily building at SkyFi and not looking for a role. I am always glad to talk about advisory and board work, speaking, and comparing notes with other engineering leaders — particularly anyone working on Earth observation, defence tech, or scaling a team through the awkward middle.