Engineering partner for startups and small product teams.
Stillwater is my company and I am the engineer: Berislav Hunjadi. I join as founding engineer or hands-on engineering lead, build or take over the product, and stay to run it for years. Last four years: first engineer, then Head of Engineering, at a US telehealth startup that grew to 10,000+ patients. Full-stack TypeScript, cloud and servers, practical AI.
What I do
Architecture, backend, frontend, infrastructure, payments, integrations. First production version in weeks, not quarters, then years of evolution on the same codebase.
Framework upgrades, migrations, CI/CD, monitoring, without pausing delivery. Meteor 1.6 to 3.4 on a 400k-line app; legacy WordPress and Magento into containers.
AWS when the product needs it (EKS, Lambda, Bedrock), a plain VPS when it does not. Kubernetes, Docker, GitLab CI with a complete preview environment per merge request (API, web, workers, own database), zero-downtime deploys, Prometheus and Grafana.
Multi-agent systems on AWS Bedrock with typed tools and versioned prompts; Claude Code in daily development; a custom AI code reviewer in CI.
How to work with me
Founding engineer or hands-on lead, long-term contract
I join as your first engineer, or as the senior engineer a small team is missing, and stay: from the first version through years of operation. Remote, EU or US time zones.
Take over and run an existing product
Monthly retainer for a company that has a product but no engineer: codebase, infrastructure, roadmap, on call. Modernized in production, without pausing delivery.
Short fixed engagement
Architecture review, an AI feature into your product, or an infrastructure rescue. A few weeks, fixed scope, a way to try before committing.
Work
Innerwell
Telehealth platform from first engineer to 10,000+ patients.
Jun 2022 – present
ContractorIQ
Nine years running a construction company’s operations platform.
2017 – 2026
Yacht4Less
Charter marketplace made fast and visible to search engines.
2025 – present
Ionian Catamarans
One boat catalogue from two booking systems.
2025 – present
Hotel Alhambra & Bellevue Lošinj
Next.js + Strapi sites with zero-downtime deploys.
2023 – present
About
Stillwater runs deep.
In thought, in architecture, in execution.
I am a software engineer from Varaždin, Croatia, with an MSc in Computer Science (University of Zagreb, FER) and 15+ years of building and operating software. I work best in small, fast teams where one person is expected to understand the business and carry a product from the first version through years of operation, as the founding engineer or as the lead the team did not have yet.
In 2022 I joined Innerwell, a US mental-health telehealth startup, as its first engineer. I shipped the first production version in three months and grew it into a platform serving 10,000+ patients: architecture, payments, integrations with EHR, pharmacy and insurance systems, AWS infrastructure, the AI features, and a team of 4–6 engineers I hired and led, as part of the leadership team working directly with the CEO.
Since 2016 I have also run Stillwater, my own engineering company, building products for clients who stay for years: a construction company’s operations platform (nine years), a yacht charter marketplace, a catamaran charter operator, two hotels.
One engineer, with AI tooling I set up and maintain myself, covers today what used to need a team. That is how I work.